Volume 10, Issue 1

The thermal degradation behaviors of PC/PMPSQ (polymethylphenylsilsesquioxane) systems were investigated by thermogravimetric analysis (TGA) under non-isothermal conditions in nitrogen atmosphere. During non-isothermal degradation, Kissinger and Flynn-Wall-Ozawa methods were used to analyze the thermal degradation process. The results showed that a remarkable decrease in activation energy ( E ) was observed in the early and middle stages of thermal degradation in the presence of PMPSQ, which indicated that the addition of PMPSQ promoted the thermal degradation of PC. Flynn-Wall-Ozawa method further revealed that PMPSQ significantly increased the activation energy of PC thermal degradation in the final stage, which illustrated that the PMPSQ stabilized the char residues and improved the flame retardancy of PC in the final period of thermal degradation process

Konjac Glucomannan (KGM) nanocrystals were prepared from the disruption of KGM by acid hydrolysis. Effect of hydrolysis time on the degree of hydrolysis of KGM and the size of nanocrystals were investigated. Results from Infrared spectroscopy (IR) showed that KGM nanocrystals were still composed of mannose and glucose like the raw KGM. Results from X-ray diffractometer (XRD) revealed that the amorphous state of raw KGM had changed into a typical β-type crystalline state of KGM nanocrystals. Results from transmission electron microscopy (TEM) indicated that irregularly oval shape nanocrystals with the mean size of 15-40 nm were observed.

The as-formed structure of gel-spun polyacrylonitrile (PAN) fiber from the solvent mixture system has been probed exploiting AFM techniques developed in the membrane industry. The surface structure of PAN membranes, prepared by phase transition under different casting conditions, was investigated by tapping mode atomic force microscopy. The results obtained show that the size and the density of these aggregates are dependent on the casting solution, namely on the type and concentration of the non-solvent. In the present work, tapping mode atomic force microscopy is used to comply with the main objective of differentiating surface morphologies of membranes.

Poly(D,L-lactic acid)-co-poly(ethylene glycol) copolymer (D,L-PLEG) synthesized by melt polycondensation was irradiated using low energy electron beam (EB) in the presence of triallyl cyanurate (TAC) and tetraallyl pentaerythritol (TAPE) as crosslinking agents. The tensile strength of D,L-PLEG/TAC and D,L-PLEG/TAPE samples increases up to 48 MPa and 28 MPa at dose of 80 kGy and 60 kGy, respectively, and decreases with further increase of dose, whereas the elongation at break decreases continuously with increasing dose. The glass transition temperature ( T g ) is improved to some extent due to the formation of molecular chain network. Degradation of D,L-PLEG is retarded with introduction of cross-linked network. The results suggest that the physical properties of crosslinked D,L-PLEG can be adjusted easily by varying irradiation dose.

A 3-dimensional finite element model is developed to simulate and analyze the temperature and degree of cure field of epoxy casting part during cure process. The present model based on general finite element software ABAQUS is verified by literature example and experimental data. The numerical results show good agreement with literature example and measured data, and are even more accurate than the simulation of literature. After modeling successfully, the influences of heat convection coefficients and temperature cure cycle ramps have on the temperature and degree of cure gradient are investigated. Moreover, the effect of non-uniform temperature and degree of cure field within epoxy casting part on mechanical properties is demonstrated. The present model provides an accurate and novel method that allows further insight into the process of cure for epoxy resin.

Graft modification of polylactic acid (PLA) with acrylic acid (AA) using double initiators was studied. The composition of the graft copolymer (PLA-AA) was characterized with Fourier transform infrared (FTIR) spectroscopy and introduction of AA was demonstrated. Differential scanning calorimetry (DSC) analysis indicated that due to the increasing graft efficacy the modified PLA had better interfacial adhesion with starch compared to neat PLA. Fracture surfaces of starch/PLA and starch/PLA-AA were observed using scanning electron microscope (SEM) and the results also demonstrated the better interfacial adhesion of the latter composite. Graft modification of PLA matrix and introduction of starch played important roles in enhancing the mechanical properties (strength and modulus) while remaining good degradability of the composite.

Coaxial-electrospinning is a new method used in tissue engineering and drug delivery field. It can spin nanofibers with shell-core structure through electrospinning of two polymer solutions. In this study, collagen was used as the outer layer or the shell and thermoplastic polyurethane (TPU) was used as the inner layers or the core. A series of tests were conducted to characterize the compound nanofiber and its membrane. Morphology and microscopy of the ultrafine fibers were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), whereas the fiber diameter distribution was understood using image visualization software (ImageJ) and measurements of solution viscosity and conductivity. Mechanical measurements were carried out by applying tensile test loads to samples which were prepared from electrospun ultra fine non-woven fiber mats. The results demonstrated that these composite nanofibers had the characters of native extracellular matrix and they could be designed as the scaffold for tissue engineering and functional biomaterials.

The miscibility and crystallization kinetics of the blends of poly(e- caprolactone) (PCL) and bezoxazine (B-m) resin was investigated by differential scanning calorimetry (DSC) and polarized optical microscopy (POM). It was found that PCL/B-m blends were miscible in the melt. Thus the blend exhibited a single glass transition temperature ( T g ), which increased with increasing B-m composition and the crystal equilibrium temperature ( T m o ) depressed with the addition of B-m from the Hoffman-Weeks equation analysis. The freezing crystallization temperature ( T fc ) for the nonisothermal crystallization on the cooling process, and the spherulitic growth and overall crystallization rates of PCL for the isothermal crystallization were depressed with the addition of B-m component, attributing it to the dilution of PCL concentration due to the addition of B-m.

Polypyrrole is a widely studied conducting polymer with excellent optical and electrical properties. Polypyrrole thin films in the pristine and iodine doped forms have been prepared by ac plasma polymerization. The in situ doping of iodine during the process of plasma polymerization modified the optical absorption behaviour of the thin films due to the incorporation of charged defects in the film structure. Optical band gap and related constants are estimated from optical absorption studies. The Urbach tail analysis of the pristine and doped thin films shows that more defect levels are created, when the polymerization was carried out in the iodine atmosphere. The electrical properties of these thin films were estimated from the conductivity measurements. It is found that in the case of iodine doped films, the optical band gap decreased and electrical conductivity enhanced when compared to the pristine ones. The results are correlated with the structural differences of the pristine and doped thin films with the help of Fourier Transform Infrared Spectroscopy (FTIR) analysis.

Optically active poly(ester-imide)s (PEIs) containing upper rim calix[4]arene were prepared in good yield by polycondensation reactions of distal calix[4]arene diol with some optically active diacid chlorides. Pyromellitic dianhydride (3) was reacted with chiral amino acids (4a-4e) to obtain the resulting imide-acids (6a-6e). The compounds (6a-6e) were converted into the corresponding diacid chlorides (7a-7e). The polycondensation reactions of calixarene diol with optically active compounds 7a-7e were carried out by two methods: bulk polycondensation under microwave irradiation and solution polycondensation in a system of triethyl amine (TEA)/dichloromethane (CH 2 Cl 2 ). The optically active PEIs had good yield and moderate inherent viscosity ranging between 0.18-0.38 dL/g. The extraction ability measurements of PEIs towards alkali metal cations (Na + , K + , Cs + ) and Ag+ showed a remarkable efficiency and selectivity toward Ag + .

Radical copolymerization of 4-vinylbenzocyclobutene (VBCB) with styrene (St) afforded the copolymer (4-vinylbenzocyclobutene-co-styrene) (VBCBSt). Reaction of VBCB-St and divinyl tetramethyl disiloxane-bisbenzocyclobutene (DVSBCB) gave the oligomer (VBCB-St-DVSBCB), which was subsequently subjected to the cure reaction. The structures of VBCB-St and oligomer (VBCB-St- DVSBCB) were characterized by FTIR and 1 H NMR, which are in agreement with the proposed structures. Molecular weights of the synthesized polymers were estimated by gel permeation chromatography (GPC). Differential scanning calorimetry (DSC) showed that VBCB-St exhibited glass transition temperature (T g > 95 °C) however it is not the case for the oligomers (VBCB-St-DVSBCB). TG measurements indicated that the polymers had the good thermal stability with decomposition temperatures (T D > 370 °C). The polymer resin possessed good film planarization in the AFM images and the process of oligomer curing on a wafer without fusion and flow. These results indicated that the oligomer (VBCB-St- DVSBCB) is a promising film material with a relatively low cost.

Elastomeric composites based on Ethylene-Propylene-Diene-Monomer (EPDM) filled with multi-wall carbon nanotubes (MWNTs) have been prepared, showing improved mechanical properties as compared to the pure EPDM matrix. The results have been discussed using the Guth model. The main focus of the study was on the electrical behavior of these conductive polymer composites (CPCs), in view of possible sensor applications. A linear relation has been found between conductivity and deformations up to 10% strain, which means that such materials could be used for applications such as strain or pressure sensors. Cyclic experiments were conducted to establish whether the linear relation was reversible, which is an important requirement for sensor materials.

Polystyrene latexes were prepared, in the presence of, vinyl benzyl chloride (VBC) monomer. These particles were synthesized in surfactant-free batch radical emulsion polymerization of styrene and VBC monomer mixture, with 2,2’- azobis(2-amidino propane)di-hydrochloride (V50) initiator. The polymerization kinetics was found to be rapid, as a function of VBC monomer concentration in the polymerization recipe. It is interesting to notice that high VBC amount leads to marked coagulum formation. The final hydrodynamic particle size was found to be slightly sensitive to the VBC concentration in the investigated range. The presence of VBC at the surface of the particles was investigated by XPS analysis.

Films of polyvinylidene fluoride (PVDF) were treated in a dielectric barrier discharge (DBD) in helium, for different exposure times. Modification of PVDF properties was followed by: contact angle measurements, ATR-FTIR spectrometry and scanning electron microscopy. The applied treatment led to the obtainment of polar surfaces, with biocompatibility characteristics. These enhancements in PVDF properties after plasma exposure, associated with the possible increase of the polymer roughness, could lead to an enhanced adhesion with other materials, condition which has to be fulfilled for a series of applications (e.g.: biosensors).

The submicron ion-exchange fibers (IEF) of polystyrene (PS) and styrene-isoprene-styrene block copolymer (SIS) blends (80/20, w/w) obtained by electrospinning technology were further sulfonated with sulfuric acid to produce strong acidic cation ion exchange fibers. Scanning electron microscopy (SEM) images showed that there were obvious increase in the diameters, scratches, cracks, and micro-pores on the rough IEF surface. Fourier transform infrared (FTIR) spectroscopy analysis showed there were many sulfonated acid groups introduced onto the benzene wreath of styrene. The maximum adsorption capacity and the adsorption rate of copper ions were carried out and their removal rate determined by spectrophotometry. The results of the adsorption for copper ions showed that submicron IEF from PS/SIS blends with a high porosity (85%) and a high specific surface (760 m 2 /g) possess a rapid adsorption rate and a high ion adsorption amount (305.9 mmg/g). This high adsorption capacity suggests that the IEF can be efficiently applied to filter out toxic metal ions, and has excellent efficiency to remove copper ions from aqueous solution.

Ethylene homopolymerization and copolymerizations with 1-hexene by three types of MgCl 2 -supported catalysts were compared. Cat-1 contains no internal electron donor (ID), Cat-2 contains phthalic anhydride (PA) as ID, and Cat- 3 contains anisole as ID. The influences of two kinds of ID on comonomer effect, the role of hydrogen, polymerization kinetics in ethylene/1-hexene copolymerization were investigated. The addition of ID improves the catalysts activities in ethylene polymerization. In comparison with ethylene homopolymerization, these ethylene/1-hexene copolymerization systems all showed strong comonomer effects. However, internal donor, especially anisole, weakens the extent of comonomer activity enhancement. When the concentration of 1-hexene is 0.6 mol/L, catalysts activities increase remarkably with adding a small amount of hydrogen. But, the addition of ID reduces the sensitivity of catalyst activity to hydrogen. The introduction of anisole increases the homo-polymerization rate rapidly at the initial stage, but makes it decay earlier. In ethylene/1-hexene copolymerization with hydrogen, the addition of phthalic anhydride as ID can stabilize the polymerization rate, but anisole accelerates the decaying trends. The results are discussed based on a kinetic mechanistic model of the ID effect on ethylene copolymerization.

Since the first contributions by Gedye and Giguere in 1986, growing attention has been registered on the use of microwave heating in organic synthesis. However still many aspects need to be clarified especially about the so called “microwave effect” and the possible degradation phenomena that may be recognized during polymer synthesis. In this work the complex cone -25,27- dipropyloxy-26,28-dioxo-calix[4]arene titanium (IV) dichloride ( 1 ) has been tested for the ring opening polymerization of L -lactide, comparing the effect of conventional heating with a possible microwave assisted strategy. The polymers obtained were fully characterized (NMR, IR, HPLC-SEC, DSC, MALDI-TOF and WAXD analysis). As expected the use of microwave irradiation induced an increase of the polymerization rate. On the other side the use of microwaves resulted in a slight loss of the control over molecular weight and molecular weight distribution if compared with a conventional thermal treatment.

Carboxylated Single Walled Carbon Nanotubes (SWNT-COOH) were functionalized using different types of amines as modifier agents to improve the compatibility with the epoxy matrix. Covalent attachment was proved by XPS and Raman spectroscopy. TGA showed that only long chain modifier agents improved the thermal stability of modified SWNTs. Epoxy-based composites were synthesized using diglycidyl ether of bisphenol A (DGEBA) as polymer matrix and modified SWNTs as reinforcing agent.

Microscratch experiments were performed to evaluate effects of uniaxial stretching by 200 % in low density polyethylene (LDPE) along parallel and perpendicular directions with respect to stretching. Penetration depth, healing depth and viscoelastic recovery have been determined. Clear orientation effects are seen. The direction parallel to the extension axis shows strong resistance to scratching and also the highest recovery (a memory effect). Unoriented material exhibits behavior intermediate between that of oriented samples in parallel and perpendicular directions. The sliding wear was determined by multiple scratching along the same groove and here also was found orientation dependence. Polarized micro-Raman experiments on the oriented LDPE samples were carried out. Since scratching and sliding wear results are strongly affected by polymer orientation, one can use both kinds of tests as a measure of orientation - and also to vary orientation to control tribological properties.

Potassium diphenyl sulfonate (KSS) and polymethylphenyl silsesquioxane (PMPSQ) were proved to be effective flame retardants for PC by the LOI test and UL-94 measurements. The thermal degradation behaviours were investigated by TGA and flame-retardant mechanism of KSS/PMPSQ/PC system was studied by the kinetic analysis methods including Kissinger method and Flynn- Wall-Ozawa method. The results showed that the activation energies of flameretardant PC (FRPC) were lower than that of pure PC at lower degree of conversion, which indicated that the KSS and PMPSQ both promoted the thermal degradation of PC in the early and middle stages. Flynn-Wall-Ozawa method further revealed that the addition of the flame retardant PMPSQ increased the activation energy of FRPC thermal degradation in the final stage, which illustrated that the PMPSQ stabilized the char residues and improved the flame retardancy of FRPC in the thermal degradation. Therefore, the improved flame-retardant behaviours of KSS and PMPSQ on PC were achieved.

The ring-opening polymerization of octamethylcyclotetrasiloxane (OTS) was carried out in an Winsor I system with dodecylbenzene sulfonic acid, sodium salt (DBSNa) as emulsifier and sulfuric acid as initiator, to clarify the mechanism of the polymerization, especially focusing on the nucleation loci, the rate of generation of nonvolatile molecules and the average diameter of generated polymer droplets. In the system where DBSNa concentration is higher than the critical micellar concentration (CMC), nonvolatile molecules were generated in the aqueous phase and their generation rate became higher with an increase in DBSNa concentration, while nonvolatile molecules were not generated at emulsifier concentrations lower than the CMC. These experimental results support that nucleation did not take place in the true aqueous phase, but originated from the micelles.

Dihydroxy-terminated poly(ethylene glycol) and MgH 2 form an efficient initiating system for the ring opening polymerization of ε-caprolactone and Llactide. Polycaprolactone- block -polyethylene glycol- block -polycaprolactone and polylactide- block -polyethylene glycol- block -polylactide were synthesized in bulk at 120 °C for 16 h under argon. MgH 2 provided a faster polymerization rate compared with other initiating systems based on non toxic metals used under vacuum. Molecular weight of copolymers varied according to the monomer / ethylene oxide units ratio. The developed procedure led to easy polymerization with better control of the design, molecular weight and polydispersity of the final material. Copolymers were characterized by SEC, DSC, 1 H and 13 C NMR and IR. Micelles in aqueous solutions were prepared by finding balance between hydrophobic polyester and hydrophilic polyethylene glycol blocks. Interest for this method is since the use of MgH 2 , environmental chemical, absence of solvent and vacuum techniques and the possible recovery of solid material without further operation.

The products of hydroxyalkylation of N,N’-bis(2-hydroxypropyl)urea (BHPU) with large molar excess of propylene carbonate (PC) posses enhanced thermal stability. These products and 4,4’-diphenylmethane diisocyanate were used as substrates for obtaining rigid polyurethane foams, which had high thermal stability and low water uptake.

Starch films were obtained by incorporating sorbitol and FeCl 3 .6H 2 O by casting. The films were exposed to pyrrole vapors to promote polymerization. PPy/starch films were characterized by rheology, elemental analysis, electrical dc conductivity measurements, X-Ray diffraction, thermogravimetry, SEM and FTIR. Optimal synthesis conditions were obtained with starch films containing 5 % w/w of FeCl 3 .6H 2 O and 10 h of exposure to pyrrole vapors. The method allowed obtaining smooth, homogeneous films, with electrical conductivity values up to ca. 3.5 x 10-6 S.cm -1 . The results suggest that a complex of starch and ferric chloride is formed properties of which are not influenced by the presence of polypyrrole. No chemical interactions were observed between polypyrrole and starch in the film.

Tetrahydrofuran-soluble block copolymer of 2,2-dimethyltrimethylene carbonate with adipic anhydride [poly(DTC -b- AA)] containing 64.7/35.3 DTC/AA in molar ratio with Mn of 12.3 104 and Mw/Mn of 1.64 was synthesized by lanthanum tris(2,6-di- tert -butyl-4- methylphenolate) catalyst at 25 C in 32 min. The copolymer was characterized by SEC, 1H NMR and DSC. Copolymers with AA block from 8.5 % to 50.8 % were prepared by changing the solvent and feeding ratio of DTC/AA.

Modification of polypropylene (PP) properties by the addition of particulate fillers has been of interest for several years. In the recent years, the simultaneous use of nanofillers and conventional reinforcing fillers and study of the effect of these hybrid systems on various properties of composite has gained the attention of many researchers. In this paper, nanocomposites based on PP/Talc/Nanoclay were prepared at various filler levels via melt compounding of the ingredients in a twin-screw extruder. Here, a polypropylene grafted maleic anhydride (PP-g-MA)/Nanoclay master batch was prepared at 140 oC. The masterbatch was then used to prepare ternary compounds through a simultaneous feeding system, in a ZSK extruder at 210 °C. The extrudate was granulated and then re-extruded through a slit die, to prepare the test specimens. SEM and XRD analysis were used to characterise the systems. Rheological behaviour of the specimens was studied using a parallel plate rheometer. In the ternary blend on comparing with the neat PP, the complex viscosity (η*) is increased with increasing overall filler content; however, at low frequencies this increase is governed by the content of nano filler while at high frequencies it is mainly determined by talc content. A similar trend was also observed for the variations of storage modulus (G′) and loss modulus (G″) with frequency. The results showed that the simultaneous use of nano and micro size fillers considerably affects the melt elasticity. It is believed that the hybrid system increases the hydrodynamic effect of filler particles in the molecular motion of the polymer.

Modification of synthetic cis -1,4-polyisoprene (PI) into bromoalkylfunctionalized polyisoprene (PIBr), an ATRP macroinitiator, was investigated by two-step chemical reaction. The PI was partially epoxidized into epoxidized polyisoprene (EPI) using m -chloroperbenzoic acid, then the EPI was transformed into PIBr by reaction with 2-bromo-2-methylpropionic acid. The results from 1 H NMR revealed that the addition product occurs in competition with epoxide ring rearrangement. The amount of bromoalkyl functionalized units was determined from 1 H NMR spectra. The graft polymerization of MMA using ATRP technique from macroinitiator units in PIBr was investigated using three different ligands, i.e. N -( n -octyl)-2-pyridylmethanimine (NOPMI), N -( n -octadecyl)-2-pyridylmethanimine (NODPMI) and 1,1,4,7,7-pentamethyldiethylenetriamine (PMDETA), resulting in formation of graft copolymer of PI and PMMA. The PMMA grafts were successfully separated from the PI backbone using acidolysis for studying their number-average molecular weights (M̄̅̅ n,SEC ) and polydispersity indexes (PDI). All of the ligands used give a increase of M̄̅̅n with MMA conversion. Comparing between 3 ligands, Cu(I)Br complexed with NOPMI shows first-order kinetic plot.

Dyeable fine polypropylene (PP) fibre has remained a problem for decades. In this paper, blends of PP with P(St-EGDMA)/P(St-MMA-BA-MA) [poly(styrene-ethylene glycol dimethacrylate)/poly(styrene-methyl methacrylate- butyl acrylate-methyl acrylate)] core shell particles, have been used for the preparation of dyeable fine PP fibres. Dyeing experiment showed that the incorporation of the designed core shell particles markedly enhanced the dyeability of fine PP fibres with three distinct disperse dyes and the shades of these dyed fine fibres were deep and bright. Mechanical tensile tests showed that the particles had slight effect on the mechanical properties of fine PP fibres. The designed core shell particles were relatively monodispersed with nanoscale, and were stable during the melt-spinning process. Spinning possibility of the blends and crystallinity and orientation of the dyeable fine PP fibres were also investigated. The possible reasons for the increased depth of shade were proposed.

A series of blend membranes of quaternized polysulfone (QPSF) and polyvinylpyrrolidone (PVP) were obtained by a novel method. The procedure of quaternization of chloromethylated polysulfone and the process of blend are synchronous. These blend membranes, prepared with quaternized polysulfone (QPSF) and polyvinylpyrrolidone (PVP), were characterized by FTIR, X-ray diffraction (XRD), tensile tests and scanning electron microscopy (SEM). The degrees of swelling of the membranes in some solvent were also measured. The ionic resistances of the membranes were measured too. With the increasing of PVP content, the properties of the membranes have changed. The tensile strength of blend membrane dropped while the degrees of swelling of the membranes in water increased. The ionic resistance of the membrane dropped with the PVP content increasing in blend membranes. The polyvinylpyrrolidone (PVP) has good compatibility with quaternized polysulfone in blend membranes.

Recent futuristic applications of flexible electret loudspeakers have garnered much interest for these novel loudspeakers. To increase the loudspeaker properties, a processing method was developed to improve the electret and mechanical properties of porous PTFE film. Taking a thin porous PTFE film as the base material, a cyclic olefin copolymer (COC) was coated to a base material to form a PTFE/COC composite film. Results show that the composite material improves the advantageous characteristics when used as an electret diaphragm for loudspeakers. By measuring the surface potential decay and the elastic modulus, properties of a standard porous PTFE film were compared to an improved composite PTFE/COC film. Experimental results showed that the composite PTFE/COC possess the following advantages: (1) 80% higher surface potential after 10 days at room temperature, (2) a better thermal resistance of charge storage, and (3) a 643% higher elastic modulus. Therefore, our novel composite material can be used to create a much improved electret diaphragm for flexible electret loudspeakers.

Preparation and characterization of novel composites, consisting of polypropylene (PP) fibres in a random poly(propylene-co-ethylene) (PPE) matrix, were investigated. These composites possess unique properties, due to chemical compatibility of the two polymers allowing creation of strong physico-chemical interactions and strong interfacial bonds. The difference between the melting temperatures of PP fibre and PPE was exploited in order to establish processing conditions for the composites. Suitable conditions were chosen so that the matrix was a liquid, to ensure good wetting and impregnation of the fibres, though the temperature must not be high enough to melt the fibres. The morphology of the composites was investigated using optical and scanning electron microscopy. Optical microscope images showed that transcrystallization of the matrix was observed on PP fibre surfaces. SEM photographs displayed a thin layer of matrix on the reinforcement, attributed to good impregnation and wetting of the fibres. Adhesion between PPE matrix and PP fibres was characterized using a microbond test inspired by a fibre pull-out technique. The results showed that adhesion was appreciably increased when PP fibres were used instead of glass fibres in the matrix. Nevertheless, thermal processing conditions of the composites caused reduction in mechanical behaviour of the reinforcement.

Hyperbranched polyurethane (HBPU) elastomers were synthesized from dimer fatty acid-ethylene glycol polyester diol (DFA-EG), toluene diisocyanate (TDI) and glycerol (GLY) by a two-step, solvent-free process. The effect of glycerol on phase separation was studied by Fourier transforminfrared (FT-IR) and differential scanning calorimetry (DSC). The thermal and viscoelastic properties of the HBPU were investigated by thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA), respectively. The transparent HBPU elastomers presented a typical amorphous morphology, with a single glass transition temperature (Tg) about -25 °C. All TGA curves showed two distinct stages of degradation with the onset decomposition temperature at 275 °C. It was found that the increasing content of GLY resulted in a decrease in the thermal stability between 295 °C and 445 °C. The results for DMA revealed that HBPU crosslinked with GLY had high elasticity up to 5.12 MPa at 100 °C. The best mechanical and viscoelastic properties were achieved at the n NCO(TDI) /n OH(DFA-EG+GLY) of 0.95, with its hardness and tensile strength values of 83 A and 13.2 MPa, respectively and the storage modulus value of 32.8 MPa. In addition, the lowest water absorptivity was 0.24% when the n NCO(TDI) /n OH(DFA-EG+GLY) equalled 1.05.

Response Surface Methodology (RSM) is a collection of statistical and mathematical techniques useful for developing, improving, and optimizing processes. RSM was used to model and optimize the electrospinning parameters for the spinning of blend CS/PVA nanofibers. In this study, chitosan (CS)/polyvinyl alcohol (PVA) blend solutions (CS (M w =1 X 10 6 ) in 2% acetic acid and PVA (M w =12 X 10 3 ) in deionized water) with different blend ratio ranging from 10/90 to 50/50 were electrospun. CS/PVA (25/75) blend ratio was chosen as base and optimum ratio due to its suitable morphological properties and diameter. In a constant ratio of blend SEM analysis shows that the diameter of nanofibers changed by varying the voltage and extrusion rate in the electrospinning process. Voltage (10-25 KV) and polymer solutions extrusion rate of (0.2-1 ml/hr) from the nozzle were chosen as variables to control the fiber diameter at similar spinning distances (10 cm). Fiber diameter was correlated to production variables by using a second order polynomial function. The predicted fiber diameters were in good agreement with the experimental results.

The aim of this study was to prepare a biocompatible and biodegradable nanoparticulate drug delivery system to increase the efficiency and bioavailability of oral drugs. Chitosan nanoparticles containing salicylic acid (SA) were prepared by emulsion method. The morphology of nanoparticles was characterized by scanning electron microscopy (SEM). Particle size distribution was examined by laser light scattering. The drug released and drug content was examined by UVspectroscopy. The effects of different initial drug loading on the drug content and drug released were investigated. The nanoparticles were spherical and the average size of them was 300 nm, the drug content was in the range of 20-35%. All the nanoparticles had a burst release initially and the burst release behavior of them conformed best to higuchi model. The release of SA from chitosan nanoparticles was Fickian.

Hollow fiber membranes of polyamide-6(PA6) with porous structure were prepared by a thermally induced phase-separation method. N-Ethyl-o/p-toluene sulfonamide was chosen as diluent. On the basis of scanning electron microscopy (SEM) images, porosity, bubble point pore diameter and pure water flux, the influential factors including polymer concentration, coagulation bath temperature, post-stretching were investigated. The results indicate that with the increasing of PA6 concentration ‘slit-shaped’ pores in inner surfaces and cellular structure in cross-sections disappear, correspondingly, the properties of membranes such as porosity and pure water flux become poor. As the coagulation bath temperature varied from 20 °C to 50°C, the pure water flux of membranes is improved from 136 to 244 L·m -2 ·h -1 . Post-stretching make the ‘interfacial micro-pores’ expand due to ‘stress concentration’ phenomenon, thus changing the structure and improving the properties of membranes. PA6 hollow fiber membranes with rational structure and high performance could be obtained by altering polymer concentration, coagulation bath temperature and post-stretching.

Poly(propylene carbonate) (PPC) is a new biodegradable aliphatic polycarbonate with poor thermal stability and mechanical properties which shows difficulty in forming film by melt-extrusion technology. Through the addition of polystyrene (PS), the melt-extrusion film processability, thermal stability and mechanical properties of PPC was improved largely. PPC/PS films were prepared in the the melt-extrusion process successfully. DSC data showed that there was some degree of miscibility between PPC and PS. SEM showed good dispersion of PS particles into PPC matrix. Improved mechanical properties and thermal stability of PPC/PS blends were attributed to homogeneous dispersing and stronger interfacial interaction of PS and PPC. These results indicate that blending PPC with PS is an efficient and convenient method to improve the properties of PPC, and the composites can be used as a common packaging material for a wide range of applications.

A model hyperbranched polymerization involving irreversible reactions between functional groups A and B in a mixture of comonomers AB x and B n ( x = 2, 3,…; n = 1, 2, …) has been studied. An algorithm simulating the reactions in computer memory was developed and converted into computer code. Simulations were applied to optimize the procedure of feeding monomers AB 2 and B 2 .

Functionalized textiles and especially cosmetotextiles are increasingly used in the cosmetics and pharmaceutical industries. A cosmetotextile allows the administration of active molecules simply and controllably. It can also be used to change the surface properties of a fabric in order to make it self-cleaning, hydrophobic or lipophobic. Different techniques have been developed over recent years to functionalize fabrics: microencapsulation, plasma, sol-gel. The adhesion of the molecules, drugs and particles that functionalize textiles can be achieved physically or chemically. This article reviews the current state of the art concerning functionalization techniques and the methods used to characterize a functionalized fabric. Based on existing results and the authors’ reflections, it provides discussion and suggestions related to choosing processes. This review also reveals the surprising lack of publications on the functionalization of textile supports.

The fire retardancy mechanism of aluminium diethyl phosphinate (AlPi) and AlPi in combination with melamine polyphosphate (MPP) was investigated in glass-fibre reinforced polyamide 6 (PA6/GF) by analysing the pyrolysis, flammability and fire behaviour. AlPi in PA6/GF-AlPi partly vaporises as AlPi and partly decomposes to volatile diethylphosphinic acid (subsequently called phosphinic acid) and aluminium phosphate residue. In fire a predominant gasphase action was observed, but the material did not reach a V-0 classification for the moderate additive content used. For the combination of both AlPi and MPP in PA6/GF-AlPi-MPP a synergistic effect occurred, because of the reaction of MPP with AlPi. Aluminium phosphate is formed in the residue and melamine and phosphinic acid are released in the gas phase. The aluminium phosphate acts as a barrier for fuel and heat transport, whereas the melamine release results in fuel dilution and the phosphinic acid formation in flame inhibition. The higher amount of aluminium phosphate in PA6/GF-AlPi-MPP stabilised the residue in flammability tests in comparison to PA6/GF-AlPi, so that this material achieved a V-0 classification in the UL 94 test.

Fiber-reinforced concretes (FRCs) have a wider application range than ordinary concretes. Properties of FRCs necessarily depend on the characteristics of the aggregates used. We have studied first effects of gamma radiation on mechanical properties of hydraulic concretes containing Portland cement, silica sand, marble, water and Nylon fibers. Compressive strength and dynamic elasticity modulus are of particular importance. In the second stage we have analyzed the changes in these mechanical properties after storage of our concretes for three years. The long storage results in a 97 % of increment in the compressive strength and simultaneous lowering by 35 % of the dynamic elastic modulus. We find a larger influence of the Nylon fibers than those of silica sand and marble on mechanical properties of the concretes.

Five methods of preparation of macroporous hydrogels are described and compared: precipitation polymerization, polymerization in presence of salt, polymerization in presence of gas-releasing compound, lyophilization and electrospinning. Crosslinked copolymers based on 2-hydroxyethyl methacrylate were selected as model hydrogels. Hydrogels were characterized by SEM microscopy, porosity, communicating/non-communicating pore ratio, pore sizes and their distributions. The advantages and drawbacks of the methods of preparation, modification of hydrogel properties, reproducibility and issues related to their preparation are discussed. The most convenient method was preparation in presence of salts. One type of porous hydrogel was based on a hydrogel matrix composed of nanofibers prepared by electrospinning method. The nanofibers have shown unique properties due to their large specific surface. The least suitable method seems to be the preparation of porous hydrogels by polymerization using gas (nitrogen) releasing initiator, 2,2´-azobisisobutyronitrile. The use of prepared porous hydrogels is intended especially for scaffolds in tissue engineering.

Block and random copolymers containing N -isopropylacrylamide and (α- D-glucofuranosyl)-6-methacrylamido units were analyzed according to their temperature dependent aggregation behavior. Whereas a 45:55 random copolymer does not exhibit any LCST behavior below 100 °C due to the incorporation of the hydrophilic glyco monomer units, the phase transition could be retained in the physiological range in block copolymers even at a glyco monomer content above 55 mol%. DSL studies revealed that the aggregates of about 50 nm are stabilized above the transition temperature when the glyco monomer block dominates, whereas a glyco block molar ratio of 45% is not sufficient to prevent precipitation of the polymers as evidenced by turbidity measurements. Temperature dependent DLS studies revealed further that below the phase transition temperature an equilibrium between single macromolecules and aggregates is formed.

As a tissue engineering biomaterial, fibrin possesses outstanding biodegradable and biocompatible features except for its weak mechanical strength which limits its ranges of further application. In this study, hybrid scaffold was obtained by mixed fibrinogen and thrombin solution homogeneously in the presence of various amounts (0, 1, 2, and 4 mg, respectively) of non-woven fabric of PLGA fiber through traditional freeze-dried method to improve the mechanical strength while keeping its biological characters. The observation by scanning electron microscopy (SEM) showed that all the fibrin sponges have porous and interconnected pore structure, irrespective of the amount of PLGA fiber incorporated. In the measurement of the scaffold shrinkage, the percent of shrinkage of fibrin sponge incorporating PLGA fiber decreased when the amount of PLGA fiber incorporated increased compared with the fibrin sponge without PLGA fiber. The compression test suggested that compression modulus of PLGA fiber incorporated fibrin sponge significantly increased against the fibrin sponge without PLGA fiber; the incorporation of PLGA fiber enabled the mechanical strength of fibrin sponge to be effectively enhanced. Rat mesenchymal stem cells (rMSCs), which is of high potential to induce tissue regeneration, was selected to seed and culture in the fibrin scaffolds with or without PLGA fiber, and the number of rMSC was tested by DNA assay and calculated to examine which sponge was more favourable for rMSC to proliferate. The results reveal that the incorporation of PLGA fiber reinforced the fibrin scaffolds and maintained their intraspace. MSCs proliferated in fibrin scaffold with PLGA fiber was obviously on average more than that without PLGA fiber in vitro.

ZnO/PMMA inorganic/organic composite microspheres were synthesized with a yield of 83 wt% via soap less emulsion polymerization. The hydrophobic ZnO nanoparticles were modified by oleic acid (OA), which could improve the compatibility between ZnO nanoparticles and methyl methacrylate (MMA) monomer in emulsion system. The existence of ZnO was indicated by the XRD characteristic peaks of the composite microshperes. The TEM micrographs showed that the morphology of the composite microspheres was uniform and ZnO nanoparticles could be encapsulated in the PMMA polymer microspheres. When the ZnO nanoparticles participated in the polymerization process, the surface morphology of composites microspheres changed from smooth to grooved which was characterized by FESEM. In addition, the fluorescence property of the ZnO/PMMA composites became stronger with the increasing amount of ZnO nanoparticles and the fluorescence absorption was stronger than that of pure ZnO.

The crystallization and thermal degradation behaviors of polyhydroxybutyrate (PHB) grafted with maleic acid (MAc) and exo-3,6-epoxy-1,2,3,6-tetrahydrophthalic anhydride (ETA) are analyzed with differential scanning calorimetry (DSC), dynamic thermogravimetric analysis (TGA), and gel permeation chromatography (GPC). It is obtained that the PHB grafted with MAc or ETA has a faster crystallization rate, larger crystallinity, and better thermal stability than the as-received PHB. The thermal stability of specimens are in the order of the as-received PHB < PHB grafted with ETA < PHB grafted with MAc. The grafting ratio of MAc is larger than that of ETA. The thermal stability of PHB can be greatly improved by grafting a small amount of MAc. The activation energy of the PHB degradation reaction are little affected by the grafted chemicals, nonetheless, the reaction order and frequency factor are significantly affected by the grafted MAc.

We reported the synthesis of nanosilica/poly(acrylate) (PA) core-shell hybrid latexes via emulsion polymerization with nanosilica as the core and acrylic copolymer as the shell. Firstly, the nanosilica was surface-functionalized with the coupling agent 3-aminopropyltriethoxysilane (APTS). Then the nanosilica tethered APTS (SIAP) further connected to acrylate monomer by covalent bond during emulsion polymerization, leading to the formation of nanocomposite PA latexes. The microstructures of obtained nanosilica/PA hybrids (SIAP/PA) were characterized by attenuated Total Reflection Fourier Transform Infrared (ATRFTIR), FT-IR imaging, transmission electron microscopy (TEM) and atomic force microscopy (AFM) in detail. The FT-IR imaging indicated the perfect compatibility between the core and the shell. Additionally, the properties of hybrid films were investigated by water contact angle analysis and mechanical property measurement. The SIAP/PA composites exhibit hydrophobic behavior, enhanced tensile strength (about 1.5 times) and high elongation (1262%).

Well-defined copolymer of methyl methacrylate (MMA) and 2-methylacrylic- acid-2-{ethyl-[4-(4-methoxy-phenylazo)-3-methyl-phenyl]-amino}-ethyl ester (MAMP) bearing pendent azobenzene groups, was synthesized via reversible addition-fragmentation chain transfer polymerization (RAFT). Copolymers with different contents of azobenzene moieties, e. g. from 12 mol % to 100 mol %, were obtained by varying the feed molar ratios of MAMP and MMA. The reactivity ratios of these two monomers were measured and calculated via the modified Kelen- Tüdos method. Glass transition temperature of the copolymers was measured by differential scanning calorimetry (DSC). Photoinduced trans-cis isomerization of azobenzene moieties in the copolymer was studied at room temperature. Films cast from the functional copolymers were characterized by photo-induced birefringence and surface relief grating (SRG).

Polymer blends comprising an unsaturated polyester resin and dispersed particles were prepared. Rubbery particles were synthesized by sequential emulsion polymerization and had core-shell morphology. Curing of materials was carried out at ambient temperature and subsequently post cured at elevated temperatures to obtain materials of consistent properties. Materials made of different particle content were prepared and their tensile properties evaluated. Effect of matrix ductility was investigated by inclusion of ethyl acrylate in the polyester resin composition. Deformation mechanisms involved in these materials were examined using transmission electron microscopy (TEM) and real-time small angle X-ray spectroscopy (RT-SAXS). Incorporation of rubbery particles in the polyester resin was found to generally improve the tensile properties of the materials. Furthermore, the deformation mechanisms were found to involve cavitation/debonding processes as evidenced from stress whitening in the failed specimen and from real-time small angle X-ray scattering experiments.

The microwave-assisted synthesis of poly(glycolic acid-co-lactic acid) (PGLA) copolymers by ring-opening polymerization of glycolide (GA) and L-lactide (L-LA) was studied. The microwave irradiation time and feed ratios on the molecular weights, as well as the thermal properties of the copolymers were discussed. These copolymers were characterized by 1 H-NMR, GPC and DSC. It was found that the largest molecular weight ([η]: 0.8745 dL/g) of PGLA5050 was obtained at the irradiation time of 5 min. The color of the copolymers changed from white to light brown, and the yield was higher with the extension of the irradiation time. The molar component ratio of GA in PGLA (F G ) was higher than the initial GA feed ratio (nGA) in the raw materials. As the nGA content increased, the glass transition temperature ( T g ) of the copolymers decreased and the melting temperature ( T m ) of the copolymers increased.

Several copolymers formed by acrylamide and diallyldimethyl ammonium chloride containing different fractions of charged diallyl residues, x, were synthesized. Solution properties of linear samples of these copolymers were studied by size exclusion chromatography coupled to differential refractive index and light scattering detectors, which allowed the determination of molecular weight averages, molecular dimensions, scaling law coefficients, and unperturbed dimensions. The results were compared with those of the corresponding homopolymers i.e., polyacrylamide and poly(diallyldimethylammonium chloride). On the other hand, crosslinked samples of the copolymers were prepared and their swelling in water was studied. The correlation between the solution properties of the linear samples and the swelling behaviour of their crosslinked counterparts can be illustrated through the relationship between the characteristic ratio of the unperturbed dimensions and the equilibrium degree of swelling since both magnitudes exhibit a similar dependence on x. Moreover, this dependence is not linear and it passes through a maximum at ca. x ≈ 0.5.

PP/nano-CaCO 3 composites with different interfacial interaction were prepared by addition of compatibilizers with the same polar groups but different backbones. The non-isothermal and isothermal crystallization behavior of PP/nano- CaCO 3 composites was investigated using differential scanning calorimetry (DSC). The results indicated that the interfacial interaction between PP and nano-CaCO 3 increased the crystallization temperature and crystallization rate of PP due to the heterogeneous nucleation of nano-CaCO 3 . The interfacial interaction between nano- CaCO 3 and compatibilizer further increased the crystallization temperature and crystallization rate of PP and induced the formation of β-crystal of PP due to the synergistic effect of heterogeneous nucleation between nano-CaCO 3 and compatibilizer. This synergistic effect of heterogeneous nucleation between nano- CaCO 3 and compatibilizer depended on the interfacial interaction between compatibilizer and PP matrix. The increased compatibility between compatibilizer and PP matrix favoured the heterogeneous nucleation between nano-CaCO 3 and compatibilizer

Conducting polyaniline (PANI) nano particles doped with HCl was synthesized by a sonochemical method. Polyaniline/poly(styrene-alt-maleic acid)/polystyrene composites with different polyaniline content were developed by solution-dispersion blending method. The influence of poly(styrene-alt-maleic acid) concentration in composite structure was also investigated. The composite dispersed solution in tetrahydrofuran (THF) was cast to fabricate conductive films with evaporation of the solvent. With only a mixing procedure and without any dispersant added, the PANI nanoparticles were well dispersed in the matrix polymer as indicated by scanning electron microscopy (SEM) images. The conductivity of obtained composites was measured with four probe technique. All of obtained composites have conductivity and between them, the maximum electrical conductivity was 2.4 S/cm. The obtained composites were characterized by FT-IR and UV-Vis spectroscopy.

The compatibilizing effect of T-shaped graft copolymers between two incompatible homopolymers A and B was studied by using the external potential dynamics (EPD) method based on dynamic self-consistent field theory. We specifically focus on the role of the concentration and the junction position of the graft copolymer on the compatibility. The blend containing compatibilizers exhibits slow dynamics during the phase separation. We observed that the compatiblizers are particularly efficient when the graft point is close to the free end of the backbone chain.

Multicompartment disks with bumpy edges could be synthesized controllably by dissolving a linear ABC amphiphilic triblock copolymer of polystyrene-b-polybutadiene-b-poly (2-vinylpridine) (PS 440 -b-PBd 1020 -b-P2VP 114 ) in selective solvent mixtures of toluene and methanol. The disk size was controllable by the initial copolymer concentration. Diameter of the disks increased with the increase of the copolymer concentration. Interestingly, through adding a homo-PS to the system morphological transition took place from multicompartment disk with bumpy edges to sphere, and to hollow sphere with bumpy surfaces. Furthermore, the diameters of the hollow spheres increased with the increase of the homo-PS content, whereas the diameters of the hollows remained unchanged. Moreover, the PB block could be cross-linked by UV irradiation, stabilizing the preformed structure.

In the presence of titanium dioxide (TiO 2 ) nanoparticles, emulsion polymerization of styrene with sodium dodecyl sulphate (SDS) as an emulsifier and potassium persulphate as an initiator was investigated in detail. It was shown that SDS concentration influences the morphology of the composite particles in higher degree. Moreover, the effects of operating variables such as emulsifier concentrations, initiator concentration, monomer concentration, and polymerization temperature on the kinetic features were also examined. The kinetic data showed that at conditions studied, the rate of polymerization over interval II was proportional to the 0.68 power of the initial emulsifier concentration, to the 2.2 power of the initial initiator concentration and to the 1.6 power of the initial monomer‟s concentration. The initiator concentration has a dominant effect on the rate of the polymerization. The appropriate conditions for polymerization were obtained when emulsifier concentration of 6.5×10 -3 mol·L -1 , initiator concentration of 4.4×10 -3 mol·L -1 , the polymerization temperature of 75 °C and the initial monomer‟s concentration of 0.288 mol·L -1 were used. The polymerization rate obtained is more favorable than that of the conventional emulsion approach. The experimental results can be reasonably ascribed to the nucleation mechanism of “TiO 2 /SDS” micelles in the emulsion polymerization of styrene.

Biomimetic formation of extracellular matrix (ECM) like coatings on artificial biomaterials provides a promising route to gain bioactive materials for tissue engineering applications. Organic ECM is also a template for apatite mineralization in bone tissue. This study was aimed at designing a multilayer film containing an ECM-like molecule on biomaterial surfaces to direct apatite mineralization and to develop biomimetic biomaterials for bone tissue engineering. A multilayer film consisting of gelatin and poly(ethylenimine) molecules was formed on a poly(L-lactic acid) substrate via electrostatic self-assembly technique. Bonelike apatite coating was formed on the multilayer film modified poly(L-lactic acid) substrate in simulated body fluids (SBFs). The amount of forming apatite could be controlled by the Ca2+ and HPO4 2- concentrations in SBF and also through the mineralization time. Gelatin terminated multilayer film can induce the apatite formation with a weak orientation in the (002) plane and the apatite is similar in composition to the natural bone. The gelatin multilayer film/apatite composite coating may serve as a promising microenvironment for bone tissue formation and growth.

UV-curable Resin/ZnO composite film, which has advantages including UV-curable property and pH buffering ability, was prepared through incorporation of pre-made ZnO nanoparticles and UV-curable resin. The resins we used in this paper were R1 and R10. R1 was Bisphenol A epoxy diacrylate (EA) dissolved in propylene glycol monomethyl ether acetate (PGMEA), and R10 was synthesized by EA, pyromellitic dianhydride (PMDA) and 2-hydroxyethyl methacrylate (HEMA), and then followed by characterization using FTIR and GPC. The ZnO nanoparticles were prepared from Zinc acetate and Sodium hydroxide in 1-butanol by hydrothermal method. “Physical Adsorption” and “Mixture Coating” were two ways to prepare the Resin/ZnO composite film. Then, the pH buffering ability of the Resin/ZnO composite film was evaluated by soaking the film in the pH4 or pH10 solution, and the variation of pH value was recorded with time. The result shows that F10/ZnO composite film obtained from R10/ZnO by “Physical Adsorption” method could be a good buffering material to justify either pH4 or pH10 solution to pH7.4 in 5 min and F10/ZnO composite film by “Mixture Coating” method could be a long time pH buffering material.

Two novel methacrylate monomers, (4-((methacryloyloxy)-hexyloxy)- benzylidene-hydrazine)-N-(4-alkyloxy)-benzene-1,8-naphthalimide (NAOPH) and (4-((methacryloyloxy)-hexyloxy)-3,5-dimethoxy-benzylidene-hydrazine)-N-(4-alkyloxy)- benzene-1,8-naphthalimide (NA3OPH) were synthesized. The polystyrenes containing 1,8-naphthalimide chromophores were prepared by copolymerization of styrene with NAOPH or NA3OPH. The obtained copolymers were characterized by GPC, 1 H-NMR and TLC. The third-order NLO properties of the monomers and copolymers were measured by Z-scan technique. Results show that both monomers and copolymers have reverse saturable absorption (RSA) and selfdefocusing effects. For monomers, NA3OPH has larger third-order NLO susceptibility χ (3) than NAOPH due to introduction of two more methoxy groups. For all copolymers, larger χ (3) is observed when content of 1,8-naphthalimide chromophores was higher.

Effects of gamma radiation and the marble particle size on compressive properties and the dynamic elastic modulus of polymer concretes (PCs) were studied. The PCs had a composition of 30 % of unsaturated polyester resin and 70 wt. % of marble as aggregate. Different types of PC were developed with the combination of one, two or three marble-particle sizes. The materials were submitted to 5, 10, 50, 100 and 150 kGy of radiation doses. Both the compressive properties and the dynamic elastic modulus values depend on the combination of the marble-particle sizes and the applied radiation dose. Higher numbers of dispersed particles per unit volume provide more resistance to crack propagation. On the other hand, longer particles give more reinforcement. As a result of these two competing effects, medium size marble particles provide the highest compression modulus

In this study, plasticized polylactide (PLA) was prepared by blending PLA with high stereoregularity and poly(ethylene glycol-co-propylene glycol) (PEPG) in a batch wise mixer and pressed into films. The influence of annealing temperature on the thermal properties and tensile properties of quenched plasticized PLA was investigated by DSC, DMA and tensile tests. It was found that plasticized PLA after cold crystallization can keep its high flexibility with an elongation at break over 300% by choosing a proper annealing temperature. The difference of crystallization morphology formed at the different annealing temperature was thought as a possible reason for this result.

Phosphorus-containing tri(acryloyloxyethyl) phosphate (TAEP) was blended with triglycidyl isocyanurate acrylate (TGICA) in different ratios to obtain a series of UV curable intumescent flame retardant resins. The fire properties of the cured films were characterized by limited oxygen index (LOI), UL 94 and Cone Calorimeter. A distinct synergistic effect was found between TAEP and TGICA. The sample TAEP2 had the highest LOI (44) value among all resins. The cone calorimeter results showed that the sample TAEP2 had the lowest peak heat release rate (297 KW/M 2 ). The thermal degradation was monitored by thermogravimetric analysis (TGA) and real-time Fourier transform infrared spectroscopy (RT-FTIR). The degradation mechanism is suggested in which the phosphate group in TAEP first degraded to form poly(phosphoric acid)s, which further catalyzed the degradation of the material to form char with emission of nitrogen volatiles from TGICA, leading to the formation of expanding char.

Chitosan was chemically modified with bulky structure, cis-5- norbornene-2,3-dicarboxylic anhydride and the characteristics of this modified chitosan was studied. Fourier Transform Infrared results show that the anhydride monomer was successfully bound to amine group of chitosan. Thermal analysis of the modified structure provides N-acylated chitosan with improved thermal stability whereas X-ray Diffraction Analysis reveals reduction in crystallinity level after modification. Scanning Electron Microscope micrograph shows the physical nature and microstructure of N-acylated chitosan with less agglomeration

Nitroxide-terminated 4VP AN copolymers have been synthesized at 125 o C using an alkoxyamine (MAMA-SG1) as a unimolecular initiator. Their compositions were compared with those published for the conventional radical 4VP-AN copolymerization. To verify the initiation potential of the copolymers containing nitroxyl end groups, they were employed in chain extension with styrene (S). Both the prepared statistic copolymer macroinitiators and related diblock copolymers, poly(4VP- co -AN) and poly(4VP- co -AN)- block -poly(S), respectively, were quaternized with methyl iodide in N,N -dimethylformamide or methanol at ambient temperature. The size-exclusion chromatography and NMR were used for the characterization of the polymers; the completeness of the quaternization was checked by the IR spectrometry.

The kinetics and equilibrium of Indanthrene Olive Green (IOG) adsorption on chitosan, from aqueous solutions, have been investigated. The chitosan was characterized by XRD, average degree of deacetylation (DD), TGA/DTG, IR, SEM and specific BET surface area. Batch adsorptions experiments were carried out in different pH and dye concentration. An acidic pH condition (4.0 to 6.0) was favorable to the adsorption process. The adsorption followed secondorder rate kinetics and the experimental equilibrium data followed Langmuir isotherm, suggesting that chemisorption might be the major adsorption mode. The adsorptions also occurred on chitosan fibers, being significantly lower than that of crushed chitosan. Thermodynamic parameters ( ΔG°, ΔH°, and S°) were calculated. The positive values of ΔH° (161.7 kJ mol -1 ) and S° (559.9 J mol -1 K -1 ) suggest that the adsorption is endothermic and that during this adsorption process the randomness of the system increases. A simplified adsorption model is also proposed.

A novel polydimethylsiloxane containing two primary hydroxyl groups at one single chain end was synthesized by five-step reactions which included esterification, hydroxyl protection, anionic ring-opening polymerization, hydrosilylation and deprotection. The prepared compounds in each step were characterized. The results showed that at each step synthesis was successfully carried out and objective products could be achieved.

The swelling of the low density polyethylene in organic liquids (cyclohexane and benzene) was studied. The area of swelling was measured as a function of temperature and time. The experimental data were used for calculating the diffusion coefficients and the activation energies of this process.

Shrimp shells from Penaeus Vannamei species were hydrolyzed for chitin extraction by a chemical and a papain enzymatic method. Composition of shells was analyzed and their microstructure was characterized before and after hydrolysis by microscopy. Chitin fibers arrangement in the tissue was preserved after chemical extraction, but after papain hydrolysis the tissue presented structural disarrangement indicating that papain reacts indistinctly with peptidic and N -acetyl linkages. Although chemical purification is very effective, by-products are not recoverable. Conversely, papain hydrolysis yields partially purified chitosan but permits aminoacids isolation, which is important in food industry. This method has other advantages such as low cost and easy accessibility of papain. Chitin and chitosan were characterized by thermogravimetric analysis, infrared spectrophotometry and capillary electrophoresis. Degree of N-acetylation (DA) was determined by cross-polarization magic angle spinning nuclear magnetic resonance (CPMAS 13 CNMR) or potentiometry and crystallinity was measured by X ray diffraction.

Carbon nanofiber (CNF)-polyethylene terephthalate (PET) blends were previously prepared by melt blending and, subsequently, melt spun in order to obtain nanostructured fibers characterized by high flame retardant properties and resistance to the combustion. The morphological analysis showed that CNFs are homogeneously distributed and finely dispersed within PET matrix. The mechanical properties in tensile testing of the fibers change in the presence of CNFs: the elongation at break increases, whereas the tenacity and the tensile strength decrease. The combustion tests by cone calorimetry reveal a relevant decrease of heat release rate, total heat evolved and total smokes released by the nanocomposites as compared to neat PET.

A series of new π-conjugated donor-acceptor copolymers, based on a naphthalene-bisimide moiety as the electron-acceptor and connected to either thiophene or dialkylfluorene as the electron-donor, were synthesized. The polymers are soluble in common organic solvents. The UV-Vis spectra of the copolymers in chloroform showed two absorption maxima at higher energies (ca. 301 - 364 nm), assigned to the π-π * transition, and at a lower energy (ca. 512 - 595 nm), ascribed to the intramolecular charge transfer between donor and acceptor units. Cyclic voltammetry revealed that the polymers were susceptible to both electrochemical oxidation and reduction, and they had a LUMO and HOMO levels ranging from -4.07 to -3.80 eV and -6.13 to -5.64 eV, respectively. The energy band gaps were estimated to be 1.48 - 2.06 eV. These results represent a positive step towards making novel compounds suitable for electronic applications.

To evaluate calcium chloride coagulation technology, two kinds of raw natural rubber samples were produced by calcium chloride and acetic acid respectively. Plasticity retention index (PRI), thermal degradation process, thermal degradation kinetics and differential thermal analysis of two samples were studied. Furthermore, thermal degradation activation energy, pre-exponential factor and rate constant were calculated. The results show that natural rubber produced by calcium chloride possesses good mechanical property and poor thermo-stability in comparison to natural rubber produced by acetic acid.

Enantiomeric star-shape block copolymers of ε-caprolactone and lactide with different molar masses and compositions were synthesized using pentaerythritol/tin(II) 2-ethylhexanoate as initiating system. Stereocomplex formation between pair of enantiomeric blocks of star arms was investigated. Thermal properties of both copolymers and obtained stereocomplexes were examined. A rise of above 50 °C of melting temperature of polylactide phase was observed as a consequence of stereocomplex creation.

Phosphorylcholine-containing poly(L-lactide) (PLLA-PC) is a kind of amphiphilic copolymer synthesized with L-lactide (LLA) as monomer and glycerophosphorylcholine as ring-opening reagent. In this paper, self-assembly nanoparticles of PLLA-PC were prepared with solvent evaporation method. The factors that affected the properties and stability of nanoparticles were investigated. Transmission electron microscope (TEM) indicated that PLLA-PC nanoparticles presented typical core/shell structure. The critical micelle concentration (CMC) was determined with fluorescent probe method. The results showed that the CMCs were quite low (< 1×10 -3 g/l) and were dependent on LLA units in the copolymer. The size of the nanoparticles was detected by dynamic light scattering (DLS). The results indicated that the size could be affected by LLA units, the amount of solvent and water in the preparation process. On the other hand, the obtained nanoparticles were stable while being stored at 4 °C, and hardly changed over the dilution with water, which was of great importance in venous injection. The solubility of clofazimine was better in aqueous solution of PLLA-PC nanoparticles than in pure water. This preliminary study suggested that PLLA-PC nanoparticles had a great potential as delivery system for hydrophobic drug.

Thermoplastic polyolefin (TPO) containing 70 wt% polypropylene and 30 wt% styrene-ethylene-butadiene-styrene grafted maleic anhydride and its nanocomposites filled with 1-5wt% silicon carbide nanoparticles (SiCp) were prepared by melt processing followed by injection molding. Tensile tests show that both Young’s modulus and tensile strength increase with increasing SiCp loading. Essential work of fracture (EWF) method was used to evaluate the fracture toughness of resulting nanocomposites. EWF test demonstrates that the fracture toughness of TPO blend generally decreases with increasing SiC p content. Shield yielding and fibrillation are the main fracture mechanisms for TPO blend and composites. SiC p are found to improve the heat deflection temperature of the TPO blend.

A kind of poly(hydroxybutyrate) complexed polymer with soy protein isolate (PcSg) was prepared using glycerol as a medium. Effect of content of SPI on thermal, mechanical properties and water absorption of the PcSg polymer was investigated. The results indicated that SPI not only is miscible with PHB, but also may improve tenacity. The PcSg polymer displayed single glass transition ranges on their differential scanning calorimetry (DSC) curves. The fracture stress and Yang’s modulus of the PcSg increased with PHB concentration, but fracture elongation declined. Water absorption of the PcSg was estimated by water absorption rate of the polymers. By the ratio of hydrophobic PHB and hydrophilic SPI, water absorption of the PcSg was efficaciously modified. It was proposed that the effect on the PcSg mainly was because of intermolecular interactions between PHB and SPI.

Chemically cross-linked chitosan (MC) containing 1,2,4,5- benzenetetracarboxylic acid (BCA) as the cross-linking agent was prepared to improve the metal ions absorption capacity of native chitosan (NC) and limit its biodegradability. The Fourier transform infra-red (FTIR) and proton neutron magnetic resonance ( 1 H NMR) results showed that BCA was successfully linked onto N-position of NC. The crystalline nature of NC was reduced significantly after cross-linking as examined by X-ray diffraction (XRD) analysis. Therefore, the glass transition temperature (T g ) of MC was higher than NC as reported by differential scanning calorimetry (DSC). Moreover, thermogravimetric (TGA) analysis showed that, MC had better thermal stability than NC. Morphology changes on the surface of NC and MC were characterized by field emission scanning electron microscopy (FESEM) and showed that MC had more porous surface than NC. In pH medium of 3 to 6, MC had excellent Cu (II) ions absorption capacity with a maximum 16 % higher than NC.

Aqueous two-phase copolymerization of acrylamide (AM) and dimethylaminoethyl methacrylate methyl chloride (DMMC) was carried out in polyethylene glycol 20000 (PEG 20000) aqueous solution and with 2,2'-azobis(2- amidinopropane) dihydrochloride (V-50) as the initiator. The effects of the temperature, the PEG 20000 concentration, the DMMC/AM molar ratio and the V- 50 concentration on the initial monomer copolymerization rate (Rp), the total monomers conversion and the molecular weight of copolymers were systematically investigated. The initial copolymerization rate increased with an increase of temperature and V-50 content, contrary to the concentration of the PEG 20000 and DMMC. The molecular weight of the copolymers decreased with increasing the reaction parameters above mentioned. The apparent copolymerization activation energy of the system was calculated to be 65.7 kJ·mol -1 according to Arrhenius equation. The optimal PEG 20000 content of the system was 15%~25% (based on the raw materials). The relationship between the initial copolymerization rate (Rp) and the initiator concentration was discussed, and the kinetics equation was Rp~ [I] 0.94 .

In the present work, the crystallinity and dimension of crystal lattice of two series of ethylene-propylene copolymers with different propylene contents, which were prepared by a fluorinated bis(phenoxyimine) Ti catalyst (FI-EP copolymers) and a conventional Ziegler-Natta catalyst (ZN-EP copolymers), respectively, were studied. It is found that the overall propylene content and crystallization condition have more marked effects on the crystallinity of the FI-EP copolymers with a random comonomer distribution than that of the ZN-EP copolymers with a heterogeneous comonomer distribution. The dimension of a -axis of the PE crystals increases more rapidly with the overall propylene content in the FI-EP copolymers, indicating that more propylene units are included into the PE crystals, whereas the a -axis of the PE crystals remains unchanged for all the ZNEP copolymers. Quenching of the samples leads to more propylene units getting included into the PE crystals. The effects of comonomer content and crystallization condition on crystallinity and dimension of crystal lattice of FI-EP and ZN-EP copolymers can be explained in terms of their different comonomer distributions.

2-Bromoisobutyric acid 4-(2-benzothiazole-2-yl-vinyl)-phenyl ester (BPBVE) was used for the heterogeneous atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) with a copper(I)bromide/2,2’-bipyridine catalytic system. Factors such as the reaction temperature and mole ratio of catalyst to initiator, which could affect the ATRP system, were discussed in the paper. The functional end group was characterized via UV-vis and 1H NMR spectroscopy. The rates of polymerizations exhibited first-order kinetics with respect to the monomer, and a linear increase in the number-average molecular weight with increasing monomer conversion was observed for these initiation systems. The polydispersity indices (PDI) of the polymer were relatively low (1.07- 1.23) up to high conversions. This PMMA with BPBVE as end group shows strong emission at blue-light area whether in solution or in solid. In particularly, emission was decreased (or quenched) with appearance of metal cations (Zn 2+ , Co 2+ , Ni 2+ , Pb 2+ , Mn 2+ , Cu 2+ , Fe 3+ , Ag + ) in DMF solution.

The insolubility in neutral condition is a major problem that confronts the further development of processing and uses of chitosan. Special emphasis has been put on the chemical modification of chitosan to explore its full potential. Studies on these methods are also encouraging and many kinds of water-soluble and alcohol-soluble derivatives have been prepared. In this article, hydroxybutyl chitosan, a new type of thermosensitive polymer, was prepared through the chemical modification of 1,2-epoxybutane. According to the FT-IR spectra, hydroxybutyl chitosan has the same basic structure as chitosan, and hydroxylbutyl group has been linked in the main chain. XRD shows that the solubility of hydroxybutyl chitosan has been improved. Hydroxybutyl chitosan solution underwent sol/gel phase transition at a certain temperature lower than 20 °C, however, at high temperature, hydroxybutyl chitosan can form hydrogel with a certain mechanical strength. Hydroxybutyl chitosan could be an ideal thermosensitive material which can be applied in drug delivery system.

A third-order nonlinear optical (NLO)-active initiator (NA3PH) was synthesized to prepare a NLO-active polystyrene (NA3PH-PSt) via atom transfer radical polymerization (ATRP). The polymerization initiated by NA3PH was studied and the third-order NLO properties of the obtained NA3PH-PSt were investigated by Z-scan technique in comparison with NA3PH. Results show that the endfunctionalized polystyrene possesses third-order nonlinear optical susceptibilities (10 -11 esu) close to NA3PH. In addition, NA3PH-PSt has good thermal stability and solubility, which holds potential for further application in NLO devices.

Phase transitions of kappa and iota carrageenan in KCl, NaCl, and CaCl, solutions were separately studied during heating and cooling processes by using fluorescence technique. Scattered light, I sc and fluorescence intensity, I was monitored against temperature to determine the critical transition temperatures and exponents. Kappa and iota carrageenans with monovalent (KCl, NaCl) salt system presented only coil to double helix (c-h) and double helix to coil (h-c) transitions upon cooling and heating processes, respectively. Two transition regions were observed in both heating and cooling of the iota carrageenan in CaCl 2 solution while in kappa carrageenan only (c-h) and (h-c) transitions was detected. During heating, dimers decompose into double helices by making (d-h) transition. At the high temperature region (h-c) transition takes place. During cooling, back transitions repeat themselves. A hysteresis was observed between (h-c) and (c-h) for the kappa and iota carrageenan salt system (except CaCl 2 ), respectively. Dimer to double helix (d-h) and double helix to dimer (h-d) transitions were observed for iota carrageenan in CaCl 2 salt. The gel fraction exponent b was measured and found to be in accord with the classical Flory-Stockmayer Model for both kappa and iota carrageenan salt systems

Long chain semiaromatic polyamides were synthesized by the reactions of decanediamine with various aromatic diacids, and characterized by Fourier transform infrared spectrum (FT-IR) and nuclear magnetic resonance (1H-NMR). The thermal behaviours were determined by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The solubility, dynamic mechanical, physical and mechanical properties of the polyamides were also investigated. The resultant polyamides have intrinsic viscosity ranging from 1.7 dL/g to 2.1 dL/g. Their melting temperatures range from 305 °C to 343 °C, and the glass transition temperatures fall in the range of 125 °C - 130 °C. The tensile strength of the polyamides is above 100 MPa.

A series of cationic perfluoralkyl acrylate copolymer latices were prepared by two-stage emulsifier-free emulsion polymerization method. Perfluoroalkylethyl acrylate (FEA) and [2-(methacryloxy)ethyl] trimethyl ammonium chloride (DMC) were used as fluoromonomer and cationic monomer, respectively. The structure and composition of copolymer were characterized by Fourier transform infrared (FTIR) and differential scanning calorimetry (DSC). Thermal stability of copolymer latex film was investigated by thermogravimetic analysis (TGA). The relationships of polymerization conditions between the conversion and coagulation ratio were discussed in detail and the optimal polymerization condition was identified. The water and oil repellency performance of perfluoralkyl acrylate copolymer latices applied to textiles is significantly investigated. Increasing the FEA amount in the emulsion will lead to increase in the contact angle and water and oil repellency on cotton fabrics. When the FEA dosage was 3.9%, the static contact angles of water and liquid paraffin on the surface of cotton fabrics treated were 142.5° and 126.5°, respectively.

Several novel ether or thioether linkage containing aliphatic polyesters and poly(alkylene dicarboxylate)s were synthesized for comparison and characterized in terms of chemical structure and molecular weight. The thermal behavior was examined by thermogravimetric analysis and differential scanning calorimetry. All the polymers showed a good thermal stability, even though lower for the ether or thioether linkage-containing polyesters. The decrement of the thermal stability appears to be more relevant in the case of the presence of sulphur atoms. At room temperature the samples appeared semicrystalline, except PTTDG and PDEDG, which were viscous oils; the effect of the introduction of ether or thioether group was an increment of the T g value, a decrement of the melting temperature and a significant decrease of the crystallization rate. The entity of the variations was found to be affected by the kind of group introduced, and the trend observed can be explained on the basis of atom electronegativity and dimensions

Poly( -hydroxy acids), especially poly(glycolic acid) (PGA), poly(lactic acid) (PLA) and their copolymers poly(lactic-co-glycolic acid) (PLGA) are novel class of commodity polymers, also used in biomedical applications. They can be synthesized with a controlled biodegradation rate and are biocompatible, bioresorbable and approved by US Food and Drug Administration (US FDA) for clinical use. Lactic acid polymers are developed in medicine (sutures, implants, orthopaedics, tissue engineering), pharmacy (controlled drug delivery systems) as well as in packaging, agriculture (mulch films, seed preservation), food applications, etc. The paper reviews recent literature data concerning lactic acid polymers synthesis (polycondensation, ring opening polymerization), physical (thermophysical, solubility, miscibility), mechanical properties, degradation behaviour, emphasizing on the poly(α -hydroxyacids) and lactic acid polymers applications in medicine and pharmacy.

It is a novel approach to the synthesize Poly(aniline) / V 2 O 5 nano composite by free radical polymerization method under different experimental conditions such as variation in time, temperature and concentration of aniline and initiator. It was indicated that V 2 O 5 itself could catalyze the oxidative polymerization of aniline. This can be attributed to the internal doping effect, which introduced flexibility to the rigid PANI backbone. TGA counseled the thermal stability of PANI. Through FTIR study, the structure of PANI was established. Comparison of polymerized aniline composite with two different initiators was done.

The phase diagram of the polypropylene (PP)/poly(ethylene- block ethylene oxide) (P(E- b -EO) blends exhibiting upper critical solution temperature (UCST) was experimentally established by using small amplitude oscillatory shear rheology, in which the binodal line was obtained by dynamic temperature ramps and the spinodal temperatures were quantitatively estimated on the basis of the theory developed by Ajji et al. The measurements were carried out in the linear viscoelastic regime in which the material functions are sensitive to phase separation.

Novel photocrosslinkable poly(ether sulfone)s copolymers with allyl pendants (AS-PES) have been synthesized from 3,3’-diallyl-4,4’-dihydroxydiphenyl sulfone (DA-DHDPS), 4,4’-dihydroxydiphenyl sulfone (DHDPS) and 4,4’- dichlorophenylsulfone (DCDPS). The resulting polymers could be photocrosslinked in the presence of thiol at room temperature. The crosslinking process was monitored by “Real Time Fourier Transform Infrared Spectroscopy” (RTIR). It proves that a small amount (1.0 wt%) of the thiol crosslinker addition is sufficient to form a chemical network under UV irradiation. After UV curing, AS-PES-20 coating showed high T g , good thermal stability and excellent resistance to the acid, salt, and alkali. Accordingly, this method could successfully provide a new approach to make rapidly photocrosslinking poly(ether sulfone) coatings without losing their good thermal properties.

The synthesis and characterization of branched polymers derived from poly (monomethyl itaconate) (PMMI) are reported. Important changes in the properties of the functionalized products were found with respect to the base polymer, establishing a close relationship with the hydrophobic/hydrophilic balance of the products. The intrinsic viscosity of the branched PMMI showed an increment in its hydrodynamic volume due to the insertion of branched molecules, which correspond to a first generation of dendrons. Their incorporation into the polymer chain caused a change in the surface energy values of the sample films and enabled the products to form stable monolayers at the air-water interface

In our earlier works, a new and viable strategy for bulk polymerization of methyl methacrylate (MMA) and styrene (St) with copolymers of poly(AMS-co- GMA) (PAG) of α-methyl styrene (AMS) and glycidyl methacrylate (GMA) has been reported. Herein, we report on the achievements of the compatibilization of the blend system of polypropylene (PP) and Nylon 6 (Ny6) and the functionalization of PP with PAG. The graft reactions of PAG onto PP in solution and molten state were investigated respectively, and the functionalized production was confirmed by the FT-IR spectra. Through SEM, the in-situ compatibilization of PP/Ny6 blends with PAG was observed. And the block copolymers of PP-b-PAG-b-Ny6 in the blends were characterized by FT-IR, which confirmed the “compatibilizing effect” of PAG in the blend system.

An amphiphilic graft copolymer having an average of 7-8 carboxyesterterminated poly(ethylene oxide) grafted sequences on each polydimethylsiloxane main chain was obtained by a multistep procedure. Through fluorescence, surface tension and laser diffractometry methods the graft copolymer was proved to undergo micellization in aqueous media. In water, the critical micellization concentrations (CMC) are dependent on pH. Two CMC values were established for pH = 4, i.e. CMC 1 = 1.01 g/L and CMC 2 = 1.73 g/L corresponding to the transition from single chain to multiple chain micelles and to intermicellar aggregation, respectively. Between CMC 1 and CMC 2 , the dimensions of micelles increased from 18 nm to 46 nm. The graft copolymer was proved to efficiently act as surfactant in the preparation of magnetite particles with a hydrophobic siloxane shell.

In this study, polypropylene/clay nanocomposites were prepared by melt blending method and their thermal conductivity and the thermal conductivity of polypropylene/multi-wall carbon nanotube (MWCNT) nanocomposites were investigated and modeled. It is found that the thermal conductivity of the PP/Clay and PP/MWCNT nanocomposites is increased with increasing temperature. The thermal conductivity of the nanocomposites is improved due to incorporation of nanoclay and MWCNT compared with pure PP matrix

Polypropylene/kaolin and unplasticised poly(vinyl chloride)/kaolin composites were prepared by directly melt mixing polypropylene (PP) and unplasticised poly(vinyl chloride) (UPVC) with maleic anhydride (MAH) and low cost kaolin via in situ extrusion process. The influences of kaolin particles and MAH in PP and UPVC matrix were discussed through investigating the flexural and morphological properties of filled PP and UPVC composites. The extrudates obtained from the extrusion process were carefully collected in order to investigate the elastic properties (extrudate swell and melt fracture). Results revealed that the above mentioned properties are strongly dependent on the presences of kaolin and MAH in both composite systems. Observation on scanning electron microscopy (SEM) analysis showed that the kaolin books (stacks of kaolin particles) were successfully delaminated thus lead to a well dispersed of kaolin particles in PP and UPVC matrix.

In this study, crystallization at different depth in the injection-molded iPP, filled with β-nucleating agent (β-NA), was investigated. According to WAXD result, one observes that the fraction of β-crystals unevenly distributes along the depth of the injection-molded parts. For iPP with lower content of β- NA, larger amount of β-crystals near the surface is shear induced; meanwhile, for the parts with higher content of β-NA, larger amount of β crystals away from the surface is β-NA induced. From the results, it could be suggested that the traditional role of nucleation agent, i.e., heterogeneous nucleation, under complex thermo-mechanical conditions during injection molding, might be suppressed.

Evolutions of molecular conformation and fiber orientation in fiber suspensions are investigated by collocated finite volume method on unstructured triangular meshes. FENE-P (Finite Extensible Nonlinear Elastic Dumbbell model with Peterlin’s approximation) model which is microstructure-based is chosen to describe the polymeric matrix and TIF (transversely isotropic fluid) model is used to calculate the fiber contribution in order to realize the coupling of flow and fiber orientation. Microstructures of molecule and fiber are obtained by analyzing the information of molecular conformation tensor and second-order fiber orientation tensor respectively. Two numerical examples are considered, namely, a planar contraction flow and a planar flow past a confined cylinder. Present results are hoping to give more insight into the microscopic details of complex flows and thus be more helpful for industrial application.

Differential scanning calorimetry (DSC) was used to investigate the crystallization behavior of polyethylene oxide (PEO) and carbon nanofiber (CNF) filled PEO systems under non-isothermal experimental conditions. The dispersion and distribution of CNF of the composites were studied using scanning electron microscopy. Studies showed the uniform segregation of CNFs in PEO. Different crystallization kinetic models (the modified Avrami equation and the combined approach of Avrami and Ozawa) were used to study the dependence of crystal nucleation on the filler content. Analysis showed that inclusion of CNF to PEO retards the crystallization of PEO at all CNF loading under study

Vinyl polymer/polyurethane hybrid latex particles with various compositions were successfully prepared via emulsion polymerization of vinyl monomer in the presence of self-emulsified polyurethane dispersion without using any surfactant. Studies were carried out on polymerization kinetics, characterization of the hybrid particles and the physical properties of nano-sized vinyl polymer particle/thermoplastic polyurethane blends. It was found that the maximum content of vinyl polymer in polyurethane hybrid particles was up to 80 percent and all of the vinyl polymer/polyurethane hybrid particles were less than 120 nm. Infrared spectroscopy, thermal gravimetric analysis and differential scanning calorimetry analysis indicated the influence of vinyl polymer on the polyurethane hybrid particles. With the polyurethane shells outside and, therefore, good compatibility with polyurethane matrix, the hybrid particles can be easily blended into polyurethane matrix. Some unusual changes of dynamic mechanical properties in the low temperature region were found in the blends of hybrid particles and thermoplastic polyurethane. With the addition of only 3%, the mechanical properties of these blends did not show a significant change. This study provided a new method to prepare hybrid particles in the absence of surfactant and made an attempt on application of vinyl polymer/polyurethane hybrid particles in the blending modification

We have studied friction, scratch resistance and electrical resistivity in high density polyethylene (HDPE) + carbon black (CB) composites in relation to electric resistivity percolation threshold. Below the threshold, CB addition lowers dynamic friction by providing a smaller surface area of contact of the composites with the pin surface; the effect is stronger at higher loads. Above the percolation concentration, an increase in friction is seen due to formation of CB agglomerates and thus an increase in the area of contact. The recovery depth in scratch testing behaves similarly as dynamic friction and for the same reasons, particularly so at high loads, with a minimum at the percolation threshold. Thus, at the threshold we have simultaneously superior scratch resistance, low dynamic friction and low electric resistivity.

In this work, polystyrene (PSt) nanocapsules were successfully prepared by one-stage redox Interfacial-initiated inversed micro-emulsion polymerization of styrene (St), the cumene hydroperoxide (CHPO) and tetraethylenepentamine (TEPA) as the redox initiation pairs. The water-soluble TEPA acted as the reducing component and the oil-soluble CHPO as the oxidant component of the redox initiation system. The primary radicals were produced mainly at the oil/water interface to initiate the polymerization of styrene (St). Core-shell polymeric PSt nanocapsules were obtained by one-stage polymerization via this method, which was supported by the techniques of transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM). The particle size and polydispersity index (PDI) of nanocapsules were determined by dynamic light scattering (DLS). The results demonstrated that interfacial-initiated inversed microemulsion polymerization to form core-shell nanocapsules containing liquid cores by one-stage is successful.

The sulfonated polysulfone (SPSU)/phosphotungstic acid (PWA)/silica (SiO 2 ) hybrid membranes were researched for proton exchange membranes. The influence of silica content on the properties of composite membranes was studied in detail. The study displays that inorganic silica particles have a great influence on membrane properties, such as membrane durability, PWA extraction, proton and methanol transport behavior, thermal stability and water uptake. Interestingly, the hybrid membrane with 2 wt.% silica content showed the best results: low PWA extraction, long membrane life time under oxidative condition, high proton conductivity, and low methanol permeability. However, excessive silica content caused a large aggregation of SiO 2 particles, leading to the deterioration of membrane properties.

MALDI-MS methodology is nowadays considered as a very reliable technique to determine the chemical structures and the molecular weight distribution of a synthetic polymer. At variance, ESI-MS occupies only a small segment in the analysis of polymers mainly because of the formation of multiple charged ion distributions, which interfere with the molecular distribution in the mass spectra of synthetic polymers. In the present communication, we want to demonstrate that, when applied to fragile polymer samples, both techniques can lead to misinterpretation since in source decomposition of the ionized oligomers can sometimes not be avoided. An accurate knowledge of the source parameters and their influences is therefore a prerequisite prior to start the analysis of the MS data. Moreover, we would like to propose that the best MS methodology to analyze fragile synthetic polymers is to associate the data obtained by both the MALDI-MS and ESI-MS techniques.

Bicyclic [2,2,1] heptane di-carboxylate (commercial product name: HPN- 68) is a novel nucleating agent with high nucleation efficiency for isotactic polypropylene (iPP). In this paper, the non-isothermal crystallization kinetics of virgin iPP and iPP nucleated with HPN-68 were investigated by means of a differential scanning calorimeter (DSC).The Caze method was used to analyze the non-isothermal crystallization kinetics. The results show that addition of HPN-68 can increase the crystallization peak temperature (T p ) of iPP greatly under the same cooling rate. Under non-isothermal conditions, the addition of HPN-68 changes the spherulite growth pattern of iPP. For virgin iPP, the growth pattern is mainly spontaneous nucleation followed by three-dimensional spherulite growth, while for iPP nucleated with HPN-68, the growth pattern is mainly heterogeneous nucleation followed by three-dimensional spherulite growth.

Poly(butylenes terephthalate) (PBT)/polycarbonate (PC)/poly(ethylenebutylacrylate- glycidyl methacrylate copolymer) (PTW) blends containing PTW as toughening modifier were obtained by extrusion and injection molding. The effect of PTW on the melt rheology of PBT/PC blend was examined by means of capillary calorimetry. The rheological properties of the blends suggested high reactivity between epoxy groups in PTW and terminal carboxylic acid group and/or hydroxyl group of PBT inhibited transesterification between PBT and PC. The effect of PTW on the crystallization of PBT in the PBT/PC/PTW blends was investigated by crystallization kinetics analysis under isothermal and nonisothermal conditions. Isothermal crystallization experiments were performed at crystallization temperature and analyzed based on the Avrami equation. A decrease of the half time of PBT crystallization t 1/2 , as well as an increase of the overall crystallization rate of PBT in the PBT/PC/PTW blends have been observed. Nonisothermal crystallization experiments were performed at given cooling rate. The Ozawa analysis is used to describe its nonisothermal crystallization behavior. It is observed that at a given cooling rate, the PTW increases the overall crystallization rate of PBT in the PBT/PC/PTW blends. This is consistent with the result obtained under isothermal crystallization condition.

Metal containing polymers are of great interest as they have proven to be the most promising materials for applications such as microelectronics, holography and magnetic recording of information. Metal containing polymers also provide an alternative to even the specialty glass materials conventionally used for optical applications. Metals such as barium, lead and lanthanum have been used to improve the optical properties such as refractive index and mechanical properties such as hardness of optical plastics. The metal-containing optical plastic materials with improved refractive index of as much as 1.60 along with the Abbe number of more than 30 have been successfully designed using these metals by the authors of this paper. To further increase the refractive index without any drop in Abbe number and to improve the hardness of the polymer matrix, titanium would be the most promising metal. Incorporation of titanium in plastic matrices to form homogeneous and optically clear compositions is a challenging task. This paper reviews the state-ofthe- art by which titanium can be dispersed in polymer matrices to form metal containing composites as optical plastics.

PET-PCT copolyesters were prepared from terephthalic acid (PTA), ethylene glycol (EG) and 1,4-cyclohexane dimethanol (CHDM) through direct esterification and the subsequent polycondensation. The chemical composition and sequence length distribution of the copolyesters were investigated by 1H-NMR and 13C-NMR. The dynamic rheological behavior and dynamic mechanical property were studied by means of ARES-RFS and DMA. The results demonstrated that the obtained PET-PCT copolyesters were random block copolyesters and the content of PCT units incorporated was always greater than the feed and the numberaverage sequence length of each block in the copolyesters was in proportion to its content. The relation between storage modulus (G’) and frequency (freq) deviated from linearity as the frequency (freq) tend to zero (the terminal region effect), and the frequency band where the terminal region effect appeared would shift to higher value with the increasing content of PCT, suggesting the presence of phase separations. Moreover, two glass transition temperatures were observed from DMA curves, which revealed the incompatibility of PET segments and PCT segments, i.e. the micro-phase separation took place in PET-PCT copolyesters.

A novel amphoteric hydrogel with semi-interpenetrating polymer networks (semi-IPNs), was prepared by entrapping linear poly[2-[(methacryloyloxy) ethyl]trimethylammonium] chloride (PDMC) into lightly crosslinked starch phosphate- graft-acrylic acid (St-OPO 3 -g-AA) network in aqueous solution. The influences including the degree of substitution (DS) of starch phosphate, the doses of crosslinker, AA and PDMC were investigated with respect to the swelling capacity. The swelling capacity of hydrogel reached 2016 g/g in deionized water and 121 g/g in 0.9 wt% NaCl solutions, respectively. The swelling behaviors of hydrogel in various salt solutions and different pH buffer solutions were discussed. The amphoteric semi-IPN hydrogels exhibited pH-sensitivity and salt-resistance.

Elastomer toughened PA6 hybrids reinforced with short glass fiber and organoclay were fabricated by melt mixing and injection molding. The structure, mechanical and hygrothermal aging behaviors of such hybrids were investigated. XRD patterns showed the absence of clay diffraction peaks in low angle region. TEM observation showed that the organoclay platelets are fully exfoliated in the PA6 matrix of hybrids. Mechanical tests demonstrated that the incorporation of organoclay into PA6/SEBS-g-MA/SGF composite lead to a significant enhancement in the elastic modulus of hybrids. However, the clay additions reduced the tensile ductility and fracture toughness of hybrids. The tensile stiffness and strength of the clay reinforced hybrids deteriorated but the tensile ductility enhanced markedly upon exposure to hygrothermal aging.

Porcine dermal collagen is successfully digested by clostridium histolyticun collagenases (CHC) at varying compositions and conditions. Collagen fragments thus prepared, with significantly low molecular weight but visible denaturation temperatures and/or triple helix structures, may be useful for clinical applications. As evidenced by Sodium dodecyl sulfate - polyacrylamide gel electrophoresis (SDS-PAGE) and gel permeation chromatography (GPC) analyses, relatively high molecular weights of α 1 , α 2 subunit, β 1 , β 2 dimmers and γ trimmers of the collagen fragments gradually disappear as their incubation temperature and/or time values increase. The time values corresponding to the disappearance of sigmoid plots in the denaturation curves, denaturation endotherm in DSC thermograms and γ bands in SDS-PAGE patterns of digested collagen specimens are the same and reduce significantly as their incubation temperatures increase. Fourier transform infra-red analyses results suggest that the percentages of preserved triple helix structures present in collagen molecules of digested collagen specimens also reduce significantly with increasing the incubation temperature and time values. Possible reasons accounting for the degradation, denaturation and physicochemical properties of digested porcine dermal collagens are explored in this study.

The surface characteristic of multi-walled carbon nanotubes (MWNTs) plays an important role in the crystallization of polyamide 6 (PA6). In this paper, 1,6-hexamethylenediamine(HMD) are grafted on MWNTs. The MWNTs before and after modification are used to fabricate PA6 composites through melt-blending. The nucleating effect of MWNTs with different surface characteristic is investigated by differential scanning calorimetry (DSC), polarized optical microscopy (POM) and Xray diffraction (XRD).The heterogeneous nucleating ability of MWNTs determined by the Dobreva method are higher for pristine than amine-functionalized MWNTs/PA6 composites with 1.0 wt% MWNTs. Addition of MWNTs induce more heterogeneous nucleation and retards the crystal growth of PA6. The presence of MWNTs facilitates the formation of α crystalline form, while amino-functionalization weakens this trend. MWNTs act as effective nucleation agents for PA6, resulting in the increased number and decreased size of spherulites. MWNTs facilitate the formation of α crystalline form of PA6. Amino-functionalization decreases the crystallization and nucleating effect of MWNTs on PA6

In this article, a series of graft polymer dispersants were conveniently prepared by the grafting through method, among which the macromonomer was synthesized with one-pot through CCTP technology. Rheology and transmission electron microscopy (TEM) were utilized to study the influence of amide content on the carbon black (CB) dispersing ability of these polymers in xylene. When the tertiary amino groups on the backbone were partly quaternized, the apparent viscosity of the obtained CB suspensions decreased remarkably and the flocculation of the CB particles are effectively suppressed. TEM observations showed that the CB particles were well dispersed by the quaternized dispersant. It could be concluded that the graft polymers with a certain amount of quaternized amino groups (20 wt.%) are an efficient dispersants of CB in organic solvent.

A modified solvent casting/particulate leaching (SC/PL) method was developed to fabricate thick three-dimensional poly(lactic acid) (PLA) scaffolds with controlled pore size and porosity, and much shorter processing time. The pasty mixture of PLA/CHCl3/NaCl was sealed in a Buchner funnel by a piston with a suction flask connected. A vacuum pump was used to facilitate the volatilization of solvent. The scaffolds were obtained by subsequent removal of NaCl in deionized water. The pore size within the scaffold was in good accordance with the particle size of NaCl (< 210, 210~310, 310~420 and 420~500 μm), all of which had more than 89 % of porosity, 1.95 ± 0.2 MPa of compressive modulus and non-cytotoxic to L929 cells. To demonstrate the applicability of the SC/VV/PL method, thick cylindrical and tubular porous scaffolds have been produced in this study. Compared with the traditional SC/PL without vacuum volatilization, the modified method, namely, solvent casting/vacuum volatilization/particulate leaching (SC/VV/PL) method, provide a more efficient way to fabricate thick scaffolds.

Three novel water soluble chitosan derivatives: N,O-(acetyl)-N- (trimethyl) chitosan chloride (ATMCS), N,O-(benzoyl)-N-(trimethyl) chitosan chloride (BTMCS), N,O-(chloracetyl)-N-(trimethyl) chitosan chloride (CATMCS) were successfully synthesized. All the derivatives were soluble in water at pH 7. The antifungal properties of the derivatives against two plant fungus Gloeosporium theae-sinensis (G. theae-sinensis) and Phomopsis asparagi (P. asparagi) were studied. The results indicated that the antifungal activities of ATMCS, BTMCS and CATMCS enhanced compared with that of N-(trimethyl) chitosan chloride (TMCS). Against G. theae-sinensis and P. asparagi, BTMCS and CATMCS exhibited much better activities than ATMCS which was may be due to the phenyl and chlorine respectively. Generally speaking, acyl modification of TMCS was effective.

The starch/natural rubber composite was prepared by blending the modified starch by esterification with natural rubber latex. The modified starch particles are homogenously distributed throughout the natural rubber (NR) matrix. In comparison with the host NR, the thermal stability of composite is significantly improved. The thermal degradation temperatures (T) and reaction activation energy (E) of composite are higher than those of the pure NR. The hardness, stress at 500%, tensile strength, permanent deformation and tear strength of composite increase linearly with the increment of dosage of modified starch.

Dendritic-linear amphiphilic block copolymer, G 1 -b-PEG, was synthesized through a convergent method. The first generation benzylic dendritic polyether, G 1 -Cl, was synthesized, and benzylic dendritic polyether, G 1 -Cl, was used to react with linear monohydroxyl terminated MPEG in alkaline solution via a convergent method. The copolymer was characterized by 1 H-NMR. The amphiphilic block copolymer could self-assemble into micelles in aqueous solution, which were used as templates to prepare dispersed silver nanoparticles in water. The morphology and structure of the hybrids were characterized by transmission electron microscopy (TEM) and ultraviolet spectroscopy (UV), 1 H-NMR. An absorbance peak at 406 nm appeared after reduction in the UV spectrum. The average diameter of G 1 -B-PEG /Ag hybrid micelles was 186 nm, and the sliver nanoparticles are stable in aqueous solution due to the stabilization of the dendritic-linear micelles.

In this study, nine ternary polymer blends based on polypropylene (PP)/polycarbonate (PC)/styrene-ethylene-butylene-styrene triblock copolymer (SEBS) with the same compositions (70%wt PP, 15%wt PC, 7.5%wt SEBS and 7.5%wt maleic-anhydride grafted SEBS (SEBS-g-MAH) as a compatibilizer) are prepared using twin screw extruder at different levels of die temperature (235-245- 255 °C), screw speed (70-100-130rpm) and blending sequence (M1-M2-M3) . In M1 procedure, all of the components are dry blended and extruded simultaneously using Brabender twin-screw extruder. In M2 procedure, PC, SEBS, and SEBS-g- MAH minor phases are first pre-blended in twin screw extruder and after granulating are added to PP continuous phase in twin screw extruder. Consequently, in M 3 procedure, PP and SEBS-g-MAH are first pre-blended and then are extruded with other components. The influence of these parameters as processing conditions on mechanical properties of PP/PC/SEBS ternary blends is investigated using L9 Taghuchi experimental design. The responding variables are impact strength and tensile properties (young modulus and yield stress) which are influenced by the morphology of ternary blend and the results are used to perform the analysis of variance (ANOVA). It is shown that the resulted morphology, tensile and impact strength are influenced by extrusion variables. Additionally the optimum processing conditions of ternary PP/PC/SEBS blends from Taguchi analysis was achieved.

Relations between the critical conversion of gelation αc and the conditions of polymer formation by living and terminated polymerization were studied. It was shown that the weight average functionality of the initial system given by the formula,Φ 22 (0)=∑ i(i-1)m i where mi is the initial concentration of an i-functional monomer, is the parameter determining the value of αc. Formulas relating the critical conversion to the kinetic parameters of polymerization processes are presented. For polycondensation processes the kinetic equation based on the concept of bond blocks is proposed. It allows for estimating the gel point even for systems in which the substitution effect takes place for one of the components. The equation α ∑ i(i-1)n i=1 is , where α is the current conversion and ni are the values specifying the concentrations of i-functional blocks. The latter values are functions of α and may be calculated kinetically.

(2,2'-(Dimethylsilanediyl)bis(oxy)bis(ethane-1,2-diyl)bis(2-methylacrylate) (Type A cross-linker), (2,2'-(methyl) (phenyl) silanediyl)bis(oxy) bis (ethane-1,2- diyl)bis(2-methylacrylate)) (Type B cross-linker), and (2,2'-(diphenylsilanediyl)bis (oxy)bis(ethane-1,2-diyl)bis(2-methylacrylate)) (Type C cross-linker) three novel cross-linkers, (divinyl monomers), containing silanes and two methacrylates group (Si-DVM) were prepared by the condensation of 2-hydroxyethyl methacrylate (HEMA) with dichlorodimethyl, (DCDM) dichloromethyl phenyl (DCMP) and dichlorodiphenyl silane (DCDPS) in the presence of triethylamine (TEA). With these cross-linkers, methyl methacrylate, (MMA) can copolymerize by free-radical cross-linking copolymerization in toluene at a total monomer concentration of 3 molL -1 and at 70 °C. The experimental results show that increasing of Si-DVM concentration resulted in a decrease in gel point and swelling degree and an increase in conversion percent and weight fraction of the gels. The obtained crosslinkers were characterized by 1 H-NMR and 13 C-NMR spectroscopy and structural characteristics of the gels were examined by using equilibrium swelling in toluene solvent, gel fraction and Fourier-transform infrared (FTIR) analysis. The morphology of the copolymers was also investigated by Scanning electron microscopy (SEM).

Hydroxylated hyperbranched polyester (HBPs) of fourth and fifth generation were obtained by three methods; one step (HBP4, HBP5), step by step (HBP4P, HBP5P) and combinations of one step and step by step (HBP1-4, HBP1- 5). The HBPs were synthesized in bulk from 2,2-bis(hydroxymethyl)propionic acid (DMPA) and pentaerythritol (PE) using acid catalysis (p-toluenesulfonic acid) and characterized by infrared analysis, 1 H and 13 C nuclear magnetic resonance, gel permeation chromatography, vapor pressure osmometry, electro spray ionizationmass spectrometry, dynamic light scattering, refractive index, thermogravimetric and differential scanning calorimetric analysis. The refractive index of HBPs were low, the infrared and nuclear magnetic resonance analysis showed evidence of the occurrence of reaction between from 2,2-bis(hydroxymethyl) propionic acid (DMPA) and pentaerythritol (PE). The molar mass values of the HBPs determined by gel permeation chromatography were different to vapor pressure osmometry measurements due to small hydrodynamic volume of the HBPs. The mass spectrometry analysis showed different acyclic and cyclic units in the HBPs. The distributions of HBPs studied by dynamic light scattering were monomodal in number and volume and bimodal in intensity. The thermal stability of the fifth generation HBPs was higher than that the fourth generation. All HBPs presented amorphous behavior

Poly(ε-caprolactone) (PCL) and PCL/Poly(N-vinylpyrrolidone) (PVP) blends are shown to have the potential to be used in a range of biomedical applications and can be processed with successive in-situ polymerization procedures. In this paper, the thermomechanical analysis of PCL and PCL/PVP blends was performed using dynamic mechanical analysis (DMA). The storage and loss moduli as a function of temperature and frequency were recorded. The nonisothermal crystallization kinetics of PCL and PCL/PVP blends were analyzed using Ozawa model and Mo-Liu equation, a combination equation of Avrami and Ozawa formulas. The Ozawa analysis failed to describe the nonisothermal crystallization behavior of blends, whereas the Mo-Liu equation successfully described the nonisothermal crystallization kinetics of PCL and PCL/PVP blends. In addition, the value of crystallization rate coefficient under nonisothermal crystallization conditions was calculated. The PCL/PVP blends compared with the pure PCL and PVP had a restrain effect on the crystallization kinetics of PCL in the blends. Combining the results of DMA and DSC, PVP effectively decreased the crystallinity of PCL and enhanced its damping properties, which indicated that PCL/PVP blends could be more suitable than PCL in some biomedical applications, as it might help in the dissipation of the mechanical energy generated by the patient movements.

A phosphorus-containing biphenyl-type phenolic resin (PBP) was prepared by dehydration polycondensation of the DOPO-disubstituted 4,4’- biphenyldimethanol compound (BDCA-2DOPO) with phenol in the presence of strong Lewis acid , in which BDCA-2DOPO was prepared by the reaction of DOPO with 4,4'-biphenyldicarboxaldehyde. The PBP resin has been evaluated as the curing agent of o-cresol epoxy resins. Experimental results indicated that the PBPcured epoxy resins exhibited good thermal stability, high char yields at 700 oC and outstanding flame retardant properties. UL 94 V-0 classifications could be obtained when the phosphorus loading in the epoxy resin is higher than 1.8 wt%.

The novel approach for in situ preparation of polymer/TiO 2 composites via low-temperature in-matrix crystallization of sol-gel prepared titania was developed and successfully applied. Rigid aromatic polyimide (PI) and flexible poly(ether-urethane)acrylate (PEUA) were used as polymer matrices and the templates for titania crystallization. Structure and morphology of prepared hybrids have been characterized by WAXD, FTIR and SEM. Chemical interaction between functional groups of the polymers and reactive inorganic component were studied. It was found that the rigid PI is more perspective matrix (instead of flexible PEUA) for carrying out the low-temperature crystallization of TiO 2 . Developed crystallization technique allowed to decrease the temperature of TiO 2 crystallization from 350-500 °C to 250 °C (at atmosphere pressure) and to prepare functional crystalline TiO 2 -based polymer composites as perspective photoactive materials. Moreover, proposed approach gives also the possibility to obtain the polymer composites with enhanced compatibility between dispersed titania and continuous polymer phases.

Phase transitions in isotactic polypropylene were investigated during isothermal crystallization and heating after isothermal crystallization using various experimental techniques. The results obtained by wide angle x-ray scattering (WAXS), light depolarization technique (LDT), differential scanning calorimetry (DSC) and optical microscopy show that crystallization of isotactic polypropylene can result in simultaneous formation of two crystal modifications, α and β. There is clear experimental evidence that β phase tends to convert into α modification during crystallization as well as during subsequent heating. Experimental results are compared with numerical simulation performed according to the model of nucleation-controlled phase transitions in multiphase systems. The results of simulation show that b phase is not thermodynamically stable in any temperature range. The reason for the appearance of β phase is related to low interfacial tension of melt vs β. It has been also shown that maximum crystallinity reached in experiments does not exceed 40-50% in agreement with the concept of constrained amorphous phase.

A series of temperature and pH responsive hydrogels were synthesized by using hydroxypropylcellulose (HPC) as temperature natural sensitive material, sodium alginate (SA) as pH sensitive material. The effect of SA to LCST has been studied and the mechanism of the influence has been presented. In addition, the swelling ratio and controlling factor of swelling process were all researched in this paper. The main results obtained are as follows: the LCST decreased gradually as SA was added into HPC; the HPC/SA hydrogel responded to both temperature and pH value of the medium; the swelling ratio reached maximum value at pH value of 6.

A diamine monomer containing ester, amide and ether functional groups was prepared and its polymerization reaction with different diisocyanates to give main chain poly(ester amide ether urea)s was investigated. The monomer was synthesized via reaction of terephthaloyl chloride with 4-hydroxybenzoic acid and subsequent reaction of the resulted diacid with 1,8-diamino-3,6-dioxaoctane. The polymers were characterized by FT-IR and 1 H-NMR spectroscopic method and elemental analysis. The resulting polymers exhibited excellent solubility in polar solvents. Crystallinity of the resulted polymers was evaluated by wide-angle X-ray diffraction (WXRD) method, and they exhibited semi-crystalline patterns. The glass transition temperatures (T g ) of the polymers determined by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) were in the range of 88-112 °C. The temperatures for 10% weight loss (T 10 ) from their thermogravimetric analysis (TGA) curves were found to be in the range of 297-312 °C in air. Also the prepared polyureas showed liquid crystalline character.

The synthesis of maghemite nanoparticles coated with triethoxysilanemonomethylether- PEG (Si- m PEG), is presented in aqueous conditions, by the “ grafting to ” process. This procedure is performed in one step, starting from anchored polymer and native nanoparticles. The maghemite nanoparticles obtained were first identified by XRD and the average diameter is about 10 nm according to the Nitrogen adsorption, XRD and TEM techniques. The nature of the catalysts (acetic acid, triethylamine, NH 4 OH and dibutyl-tin-dilaurate) used for the establishment of the covalent bond between the γ-Fe 2 O 3 particles and the Si m PEG, as well as the influence of the temperature and the reaction time, were evaluated on the grafting rate of the particles in water by TGA and FTIR techniques. Using the size exclusion chromatography, SEC technique, we showed that the monomethoxy-PEG was resistant to mild acidic up to strong basic conditions. The best ratio “time/amount of polymer” for the highest grafting rate was the use of tinbased organometallic compound (DBTL) at 80 °C during 48 h. In these conditions, a grafting rate of 54 % is achieved.

There are several benefits of using the supercritical fluid microcellular injection moulding process. The part weight, melt temperature, viscosity, moulding pressure, shrink/warpage, and cooling/cycle time are all significantly reduced. The purpose of this study is to investigate the rheological behaviour of PS melt dissolved SCF of nitrogen during Microcellular Injection Moulding process applied with Gas Counter Pressure (GCP) technology. The application of gas into the mould cavity prior to the melt filling provides a counter force against the melt front advancement, restricting the foaming process during the melt filling stage. A slit cavity is designed to measure the pressure drop of polystyrene mixed with 0.4wt% supercritical nitrogen fluid under different mould temperatures (185°C, 195°C, and 205°C), injection speeds (5, 10, and 15 mm/s) as well as counter pressures (0, 150, 300 bars). It was found that melt viscosity is reduced by up to 30% when GCP is increased from 50 to 150 bar as compared to conventional injection moulding. The non-nucleation mixture melt obtained by using a GCP of 300 bar has 32~49% lower viscosity. In addition, the glass transition temperature, T g , was found to be reduced from 96 °C to 50 °C when the applied GCP is 300 bar.

The azo sulfonamide chromophores containing long aliphatic chain were used as active nonlinear optical (NLO) materials in films prepared by spin-coating on glass surfaces. The sulfonamides were: N-{4-[{4-[(pyrimidin-2-ylamino)sulfonyl]phenyl}diazenyl]phenyl} decanamide (Amid P); N-{4-[{4-[(1,3-thiazol-2-ylamino)-sulfonyl]phenyl}diazenyl]phenyl} decanamide (Amid T) and N-{4-[(4-nitrophenyl)-diazenyl]-phenyl}undec-10-enamide (Amid N). The host matrix was a copolymer of methyl and butyl methacrylate. The formation of diffraction grating by the guest-host system was successful only in the case of Amid N. The pitch and amplitude of the grating was 930 nm and ca. 45 nm, respectively. Quantum chemical calculations revealed that the chromophores were moderate NLO-fores showing static β values of ca. 110-130 m 4 /V. Two procedures were involved to align chromophores to determine first order NLO susceptibility: a) corona poling, and b) all-optical poling. The NLO coefficient d33 determined in corona poled film was 25.2, 28.6 and 93.2 pm/V for Amid P, T and N, respectively.

A series of novel crosslinked polymer electrolyte membranes were successfully prepared based on the modification of a hyperbranched poly(amidoamine) with terminal vinyl groups. The membranes possessed the different contents of proton-generating sites (i.e., protonated tertiary amine groups) and triflate (Tf 2 N-) in the crosslinked network. They showed good mechanical and thermal stability. The water uptakes of them were ca. 8.4-24.5%. Their proton conductivity was of the order of ca. 10 -5 -10 -2 S/cm in the range of 30-80 °C, and the proton conductivity increased with improving the protonation ratio. AFM results disclosed the micro-phase separation of the hydrophilic proton-generating sites and the hydrophobic domains of Tf 2 N- ions. The resulting locally continuous hydrophilic clusters could provide proton transport channels to produce the high proton conductivity. This kind of polymer electrolyte membranes may have potential applications in PEFCs and other electrochemical fields.

A novel biodegradable polymer poly(aleuritic acid) (PAA) ( M̄w 120,000) was prepared from aleuritic acid, which was obtained from renewable resources (Lac) by using tin catalyst. Aleuritic acid (AL) was protected at 9, 10 position by dimethoxy propane. The protected AL (Pro.AL) was further polymerized to obtain linear protected polyaleuritic acid (PAL) by dehydropolycondensation. Effects of various kinetic and thermodynamic parameters were studied. After polymerization, the deprotection of PAL was carried out. The synthesized PAL and PAA were characterized by using various techniques such as FT-IR, LC-MS, SEC, NMR ( 1 H and 13 C), 13 C CP/MAS (Cross Polarization / Magic Angle Spinning) of solid PAA, DSC, SEM and TEM etc. The micelle and inverted micelle -structure in polar and nonpolar solvents are highlighted.

The isothermal crystallization behavior of two different high density polyethylene grades with monomodal and bimodal molar mass distribution was investigated by means of differential scanning calorimetry. The results indicate that extensive cocrystallization between linear short chains and long chains with short branches in bimodal polyethylene grade occurred. In contrast, polymer chains of different lengths in monomodal polyethylene exhibit different tendency to crystallize. This finding was explained qualitatively based on a general discussion of the effect of molar mass and branch content/length on crystallization tendency of polymeric chains.

Surface properties of commercially available polytetrafluoroethylene (PTFE) foils of different thicknesses were examined using three different methods: AFM, study of a electrokinetical ζ -potential and measurement of a contact angle by goniometry. It was found that the front and back sides of the foils exhibit different surface morphology and roughness, different values of the ζ -potential and contact angle. The contact angle and the ζ -potential are decreasing functions of the foil thickness.

Graft-modified rubbers including maleic anhydride grafted ethylene propylene diene monomer (MAH-g-EPDM) and 49% methyl methacrylate grafted natural rubber (MMA-g-NR, i.e. MG49 rubber) were employed to toughen polypropylene (PP) and polystyrene (PS). The results showed that Charpy impact strength of the notched PP specimens and unnotched PS specimens at room temperature was improved markedly by addition of the graft-modified rubbers. Moreover, Charpy impact strength of the plastics increased with increasing graftmodified rubbers content and the incorporation of MAH-g-EPDM enhanced impact strength of the plastics more markedly than MG49. The result of thermogravimetric analysis (TGA) indicated that the addition of MAH-g-EPDM improved the thermal stability of PP, while the incorporation of MG49 reduced it. Good compatibility between the plastics and MAH-g-EPDM and saturation of EPDM could be responsible for these mechanical and thermal features. This preliminary work may also provide some information for oil-resistant modification of plastics due to the polar groups grafted onto the backbone of rubbers.

Free-radical solution copolymerization of acrylonitrile (AN) with four comonomers including itaconic acid (IA), acrylamide (AM), methyl acrylate (MA) and ammonium salt of itaconic acid (AIA) were carried out respectively. Every copolymerization process has been named as AN/IA system, AN/AM system, AN/MA system and AN/AIA system respectively, and the attained polymer is regarded as AN/IA, AN/AM, AN/MA and AN/AIA copolymer respectively. Effect of different comonomers on the polymerization kinetics and viscosity of the spinning drop are discussed in detail. The exothermic reaction of polyacrylonitrile (PAN) precursors is determined by differential scanning calorimetry (DSC), and effect of the different comonomers on the stabilization exotherm properties of PAN precursors were also studied. It has been shown that the rate of polymerization decreases distinctly with an increase of IA content, the ammonium modification can obviously increase the hydrophilicity of copolymer. The falling ball viscosity of AN/IA system is lower when compared with the other three systems, but when under the low concentration of monomer, AN/MA system has the highest viscosity. Electron paramagnetic resonance (EPR) indicates that the peak width change for the different copolymer be mainly caused by the spin-spin interaction. The copolymer of AN/AM has the lowest starting-exothermal reaction temperature and AM can alleviate the exothermic reaction and moderate the stabilization exotherm

Curing kinetics of epoxy resin/hyperbranched poly(amide amine)s (HPAMAM) system was studied by non-isothermal and isothermal differential scanning calorimetry (DSC). Non-isothermal DSC scans indicated that H-PAMAM was an effective curing agent of epoxy resin. The apparent activation energy ( E ) was 54.3 kJ/mol calculated through Kissinger method, and the kinetic parameters were determined by Málek method for the kinetic analysis of the thermal treatment obtained by DSC measurement. A two-parameter ( m , n ) autocatalytic model (Sěsták-Berggren equation) was found to be the most adequate selected kinetic model. In addition, the predicted curves from the kinetic model fit well with the nonisothermal DSC thermogram. The isothermal DSC method was used to investigate the curing process for resin at 60, 65, 70, 75 and 80 °С, respectively. Isothermal kinetic parameters, including k 1 , k 2 , m and n , were determined based on an autocatalytic mechanism proposed by Kamal. Both models were validated for a fitting to the experimental data by the Levenberg-Marquardt method. A process to determine the initial values for the fitting procedure was also proposed. The predictions of the validated models were in good agreement with the measured data, and were therefore applicable for numerical process optimization

A series of novel poly(arylene imino) containing fluorenone group (PIKF) have been synthesized via palladium-catalyzed polycondensation. The thermal properties of PIKF are detected by thermal behavior (TG) and differential scanning calorimetry (DSC). UV-vis absorption spectra, photoluminescence are investigated. PIKF exhibit good thermal stability and high Tgs(>200 °C ). The optical properties of PIKF show that PIKF are interesting materials for further investigations to be presented as possible candidates for use as an electron transport layer (n-type) in multilayer LEDs.

Preparing tailor-made hybrid photoinitiator (PI) for specific applications continues to gain momentum. The hybrid PIs comprising both H-abstraction chromophore and coinitiator moiety are the candidate materials with energy-saving and environment-protection in the photo-curing field. So two oligomeric photoinitiators (OMKs) containing benzophenone (BP) and aliphatic tert -amines chromophore in the main-chain (OMK-2) or side-chain (OMK-1) were synthesized and characterized respectively. Photophysical investigation showed that the absorption maxima of OMKs were around 340 nm, red shifted about 5-10 nm compared to BP. Their initiation efficiencies were found to be higher than that of BP and 4,4’-bis(dimethylamino)benzophenone(MK) respectively. The reaction proceeds via a simple electron-transfer/proton-transfer mechanism. Dynamic NMR data reveal that H-abstraction reacts predominantly via alpha H of aliphatic tert amines, as might be expected on the basis of the lower ionization potential and bond dissociation energy of aliphatic amines compared to aromatic amines. The reaction mechanism of H-abstraction was confirmed by using radical scavenger 2,2,6,6-tetramethylpiperidin-1-oxy(TEMPO), which acts as a probe under photolysis reaction conditions. The volatility and migration were tested under simulated conditions, the result show that OMKs exhibited very low volatility and significantly reduced migration compared to the low molecular analogs. Results showed that the OMKs are the promising candidate as higher efficient PIs with low volatile organic compounds (VOCs) emission and reduced migration. They are suitable for environmental-friendly formulations.

Copolyesters based on L,L-lactide (LA) and ε-caprolactone (CL) with different LA: ε-CL ratios were synthesized by ring opening polymerization using zinc (L-proline) as a catalyst. Ring opening polymerization results in random P(L, L-lactide-ε-caprolactone) copolymers of molecular weights between 9,800 to 30,000 and block copolymer up to 51,800 Da. 1 H NMR spectroscopy analysis was used for calculation of monomer incorporation in the copolymer. FT-IR spectra were used to differentiate between random and block copolymer using carbonyl region splitting. 13 C quantitative NMR spectroscopy analysis coupled with information from TGA and DSC allowed determination of the polymer structure. Copolymers (CP-1, CP-2 and CP-3) prepared by ROP are random copolymer (h>1), while CP-4 prepared by ROP (sequential addition of έ-caprolactone and L, L-lactide) has a multi block character (h<1). The LA number-average sequence length (L LA ) decreased from 14 to 5 for LA-CL 80:20 to 50:50 copolymers prepared by ROP. The copolymer (CP-4) prepared by sequential addition showed the number-average sequence length (L LA ) to be 83.0.

A group of films mainly composed of sericin and poly(vinyl alcohol) (PVA), using boric acid (BA) as a modifier, were prepared by a technique of solution casting. In this work, the effect of BA and sericin on the mechanical properties and water resistance of the films was analyzed, the interior morphology of the films were described by a scanning electron microscopy (SEM), the thermal stability of the films was characterized by differential scanning calorimetry (DSC), and the reaction mechanism was proposed according to the previous literature and the test of Fourier transform infrared spectrum (FTIR). Results indicated that, the properties of the membrane were the functions of the blend ratio of sercin to PVA and the content of BA. The use of BA increased the tensile strength, improved the water resistance and the thermal stability, and varied the interior morphology of the films. The content of sericin greatly influenced the combination of properties of the films, especially the mechanical properties, interior morphology, thermal stability, and water resistance reducing with the increasing of sericin content. The films have potential to be used in materials, such as skin-care coatings for beauty, percutaneous drug delivery systems for exterior intact skin, due to the characteristics of the components and the good mechanical properties of the films.

A p -cyanophenol and allylamine based benzoxazine has been synthesized and characterized. This benzoxazine has nitrile and allyl functionalities that can polymerize, resulting in a highly crosslinked material. The DSC spectra of novel benzoxazine monomer reveal that incorporation of the nitrile and allyl group greatly decreases the ring-opening temperature of oxazine rings (140°C). The IR spectra of curing process indicate that the polymerization of oxazine ring accompany with the curing reaction of allyl and nitrile groups. Benzoxazine monomers with one or none of the two functionalities were also prepared to study structure effect on thermal properties of resulted polymer. The comparison of results confirms that introducing the two functionalities improved glass transition temperature (238 °C), thermal stability of polybenzoxazine (T 5% =340 °C), and char yield (57%).

A Polyhedral oligomeric silsesquioxane (POSS) containing eight 3- chloropropyl groups was synthesized and incorporated into poly(methyl methacrylates) to form star polymer. First, octa(3-chloropropyl) POSS [(ClCH 2 CH 2 CH 2 ) 8 Si 8 O 12 ] was prepared by hydrolysis and condensation of 3- chloropropyltriethoxysilane, and then two star-shaped POSS/PMMA composites with different POSS content was synthesized at 110 °C, using octa(3-chloropropyl) POSS as an multifunctional initiator, CuCl and 2-2’ bipyridine (Bpy) as catalyst system. The structures of octa(3-chloropropyl) POSS and star-shaped POSS/PMMA composite were characterized by analytical methods including FTIR, NMR, GPC and XRD, with results showing that POSS molecule was successfully formed which accorded well with the reported work and was dispersed into PMMA matrix evenly by atom transfer radical polymerization method. The TGA results indicated that synthetic POSS molecule possessed good thermal stability, and the thermal stability of POSS/PMMA composite enhanced with the increase of POSS content, which is due to the incorporation of inorganic POSS molecule

Two grades of LLDPE were analysed by a number of methods for fractionation and molecular structure determination (molecular weight, branching density). Methods used were: preparative fractionation according to comonomer content (TREF) and molecular weight (solvent - non solvent), CRYSTAF, SEC, SEC-FTIR and NMR. We explore different ways of combining and processing data to obtain two and three dimensional results. Methods to correct for chain end effects in and construct bivariate distributions from preparative TREF + SEC + NMR data is presented. The methods studied have different drawbacks and advantages. Preparative TREF + SEC + NMR and SEC-FTIR provide most information relative to the labour requirement. In general, the most complete information is obtained from combined interpretation of results from different methods.

In the last decade, the interest in physical organogels has grown rapidly with the discovery and synthesis of a very large number of diverse molecules, which used organic solvents at low concentrations. New organogels based on poly (acrylic acid) (PAA) and cellulose acetate (CA) were prepared as thin films to study properties and swelling behavior. In organogels synthesis different crosslinking agent and initiator concentrations were studied. The swelling for PAA/CA organogels was carried out with acetone at 3 different temperatures (30°, 40° and 50 °C) and pH of 6.5 (pH acetone = 6.5). The higher swelling for PAA/CA organogels was 770% for 25PAA/75CA composition ratio with 3%wt N,N´-methylene-bis acrylamide (MBA) and 1%wt potassium persulphate (KPS) at 30 °C. The films were analyzed by FTIR and the presence of functional groups of each polymer was confirmed without secondary reactions. The DSC analysis indicated two glass transition temperatures (T g ); at 106 °C corresponding to PAA and 86 °C, corresponding to CA, respectively, indicative of phase separation, characteristic of gels. Surface morphology was analyzed by Scanning electron microscopy (SEM) showing smooth surface and small crystal forms.

The bulk polymerizations of styrene were performed in the presence of a novel trinitroxide, 2,4,6-tri(4’-oxy-2’,2’,6’,6’-tetramethyl-1’-piperidinyloxy)-1,3,5- triazine (TTPT). Typical features of controlled polymerization were observed, such as the first-order kinetics, the molecular weights ( M n) linearly increased with the conversion, and relatively narrow molecular weight distributions ( M w / M n ). The 1H NMR was used to characterize the obtained polystyrene. The most of obtained polymers at 110 °C were the polymer with two-arm linear structure, not the expected three-arm structure, which was confirmed by the analysis of degradation of obtained polymer by ascorbic acid. A proposed polymerization route of styrene mediated by TTPT was also discussed.

The insolubility in neutral condition is a major problem that confronts the further development of processing and uses of chitosan. Special emphasis has been put on the chemical modification of chitosan to explore its full potential. Studies on these methods are also encouraging and many kinds of water-soluble and alcohol-soluble derivatives have appeared. In this article, hydroxybutyl chitosan, a new type of thermosensitive polymer, was prepared through the chemical modification of 1,2-epoxybutane. Hydroxybutyl chitosan solution underwent sol/gel phase transition at a certain temperature lower than 20 °C, however, at high temperature, hydroxybutyl chitosan can form hydrogel with a certain mechanical strength. Hydroxybutyl chitosan could be an ideal themosensitive material applied in drug delivery system, tissue engineering and other biomedical fields.

In this paper we present two different techniques for the preparation of single site heterogeneous catalyst. The first method consists in the impregnation of a solution of the organometallic compound in MCM41. The second method intends to establish the in situ synthesis of the complex within the solid’s pores by the reaction of the organic ligand with the metal cation previously introduced in the support. The direct deposition of the organometallic complex in the support resulted in an active catalyst which gives polyethylene with the same microstructure as the one obtained with the related homogeneous systems. The heterogeneous catalysts obtained by reaction of the ligand with the metal already present in the support showed a lower catalytic activity.

A series of polyurethanes (PURs) were prepared by metal-free method, containing polycaprolactone (PCL) as the soft segment with molecular weights of 1600, 2400 and 2600. PCL was obtained by the ring-opening polymerization of ε- caprolactone in the presence L-alanine and L-phenyloalanine. The structure of synthesized oligoesters and PURs were spectroscopically confirmed. The molecular weights, mechanical and thermal properties of the obtained materials were reported.