Volume 6, Issue 1

The process of fabrication of carbon fibres from polyacrylonitrile (PAN) fibres is composed of two steps including oxidative stabilization at low temperature and carbonization at high temperature in an inert atmosphere. Due to the high price of the raw material (special PAN fibres), carbon fibres are still expensive. It is shown that it is possible to produce desirable carbon fibres from (cheaper) commercial PAN fibres. In order to achieve this, it is necessary to make some changes in the conventional stabilization procedure to reach complete stabilization.

3,4-Ethylenedioxythiophene derivatives with aromatic, in most cases mesogenic, side groups were synthesized and their liquid crystal behaviour was characterized. These monomers were polymerized oxidatively to charged, electrically conductive polythiophenes. X-ray and atomic force microscopy studies were performed. Films of theses polythiophenes achieved via in situ polymerization were prone to a significant increase of the conductivity by annealing.

Composites from Na-montmorillonite with a content in inorganic material ranging from 3 to 98 wt % were prepared in situ either by copolymerization of ethylene and CO or by terpolymerization of ethylene, propene and CO using a palladium(II) catalyst modified with 1,3-bis(diphenylphosphino)propane. This catalytic system is active in polar media and allowed to produce nanocomposites starting from unmodified Na-montmorillonite in water-methanol solutions. The morphological analysis, performed on samples with less than 40 wt % silicate by XRD and TEM, showed the formation of either intercalated or exfoliated (nanocomposite) structures, depending on the initial amount of the layered silicate in the reactor as well as the presence of propene as comonomer. Improved thermal stability of the hybrid materials, as compared to the corresponding organic polymers, was shown by TGA. A preliminary study of the blending of some polyketone nanocomposites with polyamide (nylon-6) was carried out by melt mixing at high temperature in a Brabender mixer.

The synthesis of a new olefin-derived acrylate monomer, 1-methyl-1-propylhexyl acrylate (1-MPHA), starting from 1-pentene, is reported. 1-MPHA was found to be polymerizable to high conversion by conventional free radical means. Homopolymerization of the monomer in benzene and toluene progressed faster in toluene than in bulk. Kinetic studies show 1-MPHA to be a relatively slow reacting monomer. The homopolymer of 1-MPHA was found to be thermally stable to about 200 °C, and soft at room temperature, with a T g of -43 °C.

Sucrose esters (SE) are surfactants with potential pharmaceutical applications because of their low toxicity, biocompatibility, and excellent biodegradability. Biodegradable and biocompatible copolymeric hydrogels based on glucose-6-acrylate-1, 2, 3, 4-tetraacetate (GATA) and methacrylic acid (MAA) were designed and synthesized. Because of the growing importance of sugar-based hydrogels as drug delivery systems, these new pH-responsive glucose-containing copolymeric hydrogels were investigated for oral drug delivery. The GATA monomer was synthesized and characterized. The copolymeric hydrogel was synthesized by free-radical polymerization. Azobisisobutyronitrile (AIBN) was the free-radical initiator employed and Cubane-1, 4-dicarboxylic acid (CDA) linked to two 2-hydroxyethyl methacrylate (HEMA) group was the crosslinking agent (CA) used for hydrogel preparations. The hydrogels were characterized by differential scanning calorimetry and FT-IR. Equilibrium swelling studies were carried out in enzyme-free simulated gastric and intestinal fluids (SGF and SIF, respectively). A model drug, olsalazine [3, 3-َazobis (6-hydroxy benzoic acid)] (OSZ) an azo derivative of 5-aminosalicylic acid (5-ASA), was entrapped in these gels and the in vitro release profiles were established separately in both enzyme-free SGF and SIF. The drug release was found to be faster in SIF. The drug-release profiles indicated that amount of drug release depends on their degree of swelling and crosslinking.

Fluorocarbon films with an exceptionally high CF 2 content were obtained by plasma polymerization using a low pressure radio frequency discharge operated with a mixture of argon and tetrafluoroethylene. Substrates were placed in a remote position downstream the discharge. Gas pressure, discharge power, substrate position, gas composition and substrate temperature were changed to alter the chemical structure of the plasma polymers. The properties of the films were characterized by X-ray photoelectron spectroscopy (XPS), spectroscopic ellipsometry and contact angle goniometry. A pronounced increase of the CF 2 content was obtained for elevated substrate temperatures and increased amounts of tetrafluoroethylene in the process gas. Applied as a model surface in studies of interfacial phenomena on polytetrafluoroethylene (PTFE), transparent PTFE-like thin films enable the use of numerous optical techniques not applicable to common PTFE foils.

A novel approach has been adopted for synthesizing composite polymer electrolytes with a blend of atactic poly(methyl methacrylate) (a-PMMA) and isotactic PMMA (i-PMMA) owing to their ability to form stereocomplex structures, especially double helix like structures. Nanocomposite polymeric electrolytes based on gel polymeric electrolyte (GPE) consisting of stereocomplex PMMA, propylene carbonate (PC) and LiClO 4 has been synthesized. For the stabilization of polymer electrolytes and for good processability, fumed silica nanoparticles have been added in different proportions up to 6 wt% to GPE resulting in composite polymeric electrolytes (CPEs). Thermally stable, low volatile CPEs without the cost on electrochemical stability can thus be obtained, being promising candidates as polymeric electrolytes in many electrochemical devices in general, and in particular electrochromic windows.

Combinatorial chemistry and high-throughput experimentation have drawn great attention in recent years because of their significant advantages in increasing the research productivity. One of the emerging fields is their application in polymer science. Herein we describe the high-throughput optimization of purification conditions for polymers prepared via atom transfer radical polymerization using an automated synthesizer. The effects of the column materials, column lengths and eluent volumes on the purification efficiency as well as the molecular weights of the obtained purified polymers were systematically investigated for the first time. The optimum purification conditions for the removal of copper catalysts are provided. As a result an online high-throughput purification workflow using SPE cartridges is now available for the utilization in automated parallel synthesizers for ATRP screening experiment.

Non-isothermal dielectric analysis (DEA) and differential scanning calorimetry (DSC) techniques were used to study the epoxy nanocomposites prepared by reacting 1,3,5,7,9,11,13,15-octa[dimethylsiloxypropylglycidylether] pentaciclo [9.5.1.1 3,9.15,15 .17,13 ] octasilsesquioxane (ODPG) with methylenedianiline (MDA). Loss factor (ε”) and activation energy were calculated by DEA. The relationships between the loss factor, the activation energy, the structure of the network, and the mechanical properties were investigated. Activation energies determined by DEA and DSC, heat of polymerization, fracture toughness and tensile modulus show the same profile for mechanical properties with respect to ODPG content.

Transmission electron microscopy (TEM), small angle X-ray (SAXS) and dynamical mechanical thermal analysis (DMTA) were used to characterize the morphology and thermo-mechanical properties of hybrid organic inorganic materials. These materials were based on polyimide (PI) and tetraethoxysilane (TEOS). Polyimide polymer is prepared from 4,4’-oxydianiline (ODA) 2,2-Bis(3- amino-4-hydroxyphenyl) hexafluoro-propane (6F-OHDA) pyromellitic dianhydride (PMDA) polyamic polymer. In one family of hybrid materials 3- isocyanatopropyltriethoxysilane (ICTS) is used as coupling agent in order to enhance the interfacial interaction between polyimide and silica. It was possible to modulate the morphology as well as the optical and thermo-mechanical properties of these hybrid materials depending on the formulation used. TEM and SAXS analysis indicated that silica domains on the nanoscale level are obtained when coupling agent is used in the formulation. Additionally the TEM and SAXS analysis indicated that miscibility of the organic and the inorganic phases on the molecular scale is obtained in the hybrid films when ICTS as coupling agent is added to the polyamic acid. These techniques show a fractal structure of the hybrid materials with coupling agent. This was confirmed with DMTA analysis which shows very high temperature relaxation (more than 450°C). From this result it could be derived that the addition of ICTS causes a morphological transformation from discrete particulate microstructure to fine interpenetrated or co-continuous phases. The intimate miscibility of the phases is accompanied at the same time by the amelioration of thermo-mechanical properties of the hybrid films.

Free radical homo- and copolymerization of the highly polar 3-( N -[2- methacryloyloxyethyl]- N,N -dimethylammonio)propane sulfonate with the nonpolar n-butylmethacrylate was investigated in the ionic liquids 1-butyl-3-methyl imidazolium tetrafluoroborate and 1-butyl-3-methylimidazolium hexafluoro phosphate, and compared to analogous polymerizations in standard solvents. Higher molar masses are obtained for the zwitterionic homopolymer when the polymerization is carried out in an ionic liquid compared to the classical reaction in water. Although homopolymerization of the sulfobetain monomer as well as of n butylmethacrylate results in phase separation during the polymerization process, copolymerization of a stoichiometric ratio of the two monomers in the ionic liquids produced transparent gels indicating that no macrophase separation occurs. The use of ionic liquids as reaction medium improved the copolymerization behavior of the two methacrylates significantly. Whereas only minor amounts of n-butyl methacrylate were incorporated in the copolymer when synthesized in acetonitrile, the content of the non-polar monomer units in the zwitterionic copolymer approached increasingly its content in the polymerization mixture when ionic liquids were employed as solvents.

The phase behavior of a melt of periodic two-scale multiblock copolymers has been theoretically studied in the framework of the Weak-Segregation Limit theory. The effect of the structural symmetry of the macromolecules on the vertex functions of the Landau free energy expansion is considered in detail. The existence of a thermodynamically stable mesophase with a two length-scale space periodicity has been revealed for a melt of monodisperse periodic heteropolymers.

The changes in the chemical structure and the physical properties of a filled crosslinked polydimethylsiloxane rubber were monitored as a function of various ageing factors. The variables included photochemical, thermal, salt-fog ageings and exposure to acid vapours. Unaged and aged samples were studied by IR spectroscopy, hardness measurements, Differential Scanning Calorimetry (DSC) and thermogravimetric analysis (TGA) coupled with IR spectroscopy. No significant oxidation was detected after all ageings, except for nitric acid treatment. The presence of aluminium trihydrate was clearly identified as responsible for the observed chemical changes. Then an important vulnerability of this filled silicone rubber towards the cross-linking reactions provoked by usual ageings was also detected. The DSC-thermoporosimetry measurements of the mesh size distribution gave a comparison of cross-linking densities for each ageing. The complementary analysis with TGAIR allowed us to differenciate the thermal stability of the formulation after various ageings and to acquire new knowledge about thermal decomposition.

The purification process of commercial organoclays and the beneficial effect of the impurities removal on the mechanical properties of the EVA exfoliated and intercalated nanocomposites are described in this paper. Mechanical properties such as Young modulus are improved, without any change in morphology in the exfoliated nanocomposites and an improvement of intercalation degree in the intercalated nanocomposite as demonstrated by rheological test is observed.

A new triblock copolymer consisted of a double-hydrophilic diblock and a fluorinated block, namely poly(ethylene glycol)-b-poly[2-(dimethyl amino)-ethylmethacrylate]-b-poly(2,2,3,3,4,4,5,5-octafluoropentylmeth acrylate) (MePEG-b-PDMAEMA-b-POFPMA), was synthesized via oxyanioninitiated copolymerization. The hydroxyl group of poly(ethylene glycol) monomethyl ether (MePEG) reacted with potassium methylsulfinyl carbanion (DMSO-K+) and converted into a potassium alcoholate macroinitiator (MePEG-K). It could initiate DMAEMA monomer to yield a hydrophilichydrophilic diblock copolymer. If not quenched, the living chain could be subsequently used to initiate a second fed monomer such as OFPMA to produce a new triblock copolymer MePEG-b-PDMAEMA-b-POFPMA. As a comparison, the analogous triblock copolymers with different lengths of PDMAEMA and identical length of POFPMA were prepared. These copolymers were characterized by the measurements of 1 H NMR, 19 F NMR, and gel permeation chromatography (GPC). The results indicated that they had relatively low polydispersities ( M w / M n ̅ :1.25 −1.27) . The comparison of the critical aggregation concentration (CAC) of diblock copolymer MePEG-b- PDMAEMA and triblock copolymer MePEG-b-PDMAEMA-b-POFPMA has been investigated by measurements of surface tension and electrical conductivity. It was also found that the lower critical solution temperatures (LCSTs) of the di- and triblock copolymers varied with different factors, including the chemical structure, the length of DMAEMA block, and the concentration of the aqueous solution.

The molecular weight of an extended metallo-supramolecular polymer, based on a α,ω- bis -terpyridine-poly(ethylene glycol) polymer linked via ruthenium(II) ions, was determined by gel permeation chromatography, viscosimetry as well as analytical ultracentrifugation. An optimized GPC method was applied for the first time to this kind of chain extended supramolecular polymers and the obtained results showed a good agreement with viscosimetry and analytical ultracentrifugation. A chain extended polymer with an average molecular weight of around 140 000 was found. These results clearly demonstrate that well-soluble high-molecular-weight metal-containing coordination polymers that are based on well-defined telechelics can be synthesized and fully characterized.

Poly(thiodiethylene terephthalate) (PSDET), poly(thiodiethylene adipate) (PSDEA), poly(diethylene terephthalate) (PDET) and poly(diethylene adipate) (PDEA) for comparison were synthesized and characterized in terms of chemical structure and molecular weight. The thermal behavior was examined by thermo gravimetric analysis and differential scanning calorimetry. All the polymers showed a good thermal stability, even though lower for the sulfur-containing polyesters. At room temperature they appeared as semicrystalline materials, except PDEA, which was an oil; the effect of substitution of ether oxygen atoms with sulfur ones was a lowering in the Tg value, an increment of melting temperature and an increase of crystallization rate. The results were explained as due to the presence of flexible C-S-C bonds in the polymeric chain.

In present paper we report on a preparation of hybrid microgels filled with gold nano-particles (AuNPs). Temperature-sensitive VCL/AAEM microgels have been used as containers for deposition of Au by in situ formation of gold nano-particles. Synthesis of AuNPs has been performed by two methods: a) reduction of chloroauric acid with sodium borhydride and b) reduction of chloroauric acid by sodium citrate under ultrasonic agitation. In both cases AuNPs were deposited directly into microgels leading to formation of composite particles which exhibit temperature-sensitive properties, tunable gold contents and high colloidal stability. The influence of Au load on microgel size, morphology, swellingdeswelling behaviour and stability is discussed.

A dimethyl dihydrogenated tallow ammonium bentonite, edge modified with 1-hydroxydodecane-1,1-diphosphonic acid, was activated by intercalation of polyethylene- block -poly(ethylene glycol). A high-density polyethylene (HDPE) nanocomposite was produced by the gradual dilution of the intercalated organoclay with HDPE, via melt mixing, until a final clay concentration of 0.3 wt% was reached. While polymer crystallinity was unaffected by the addition of the clay, polymer transparency increased dramatically. Microscopic examination of compression molded films verified that polymer nucleation increased to such an extent that the normal spherulitic structure was completely absent. A significant reduction in gas transmission accompanied the increased film clarity. Compared to the pure polymer, oxygen and water vapor permeabilities were reduced by approximately 55 and 70%, respectively. With proper dispersion, significant improvements in both physical and barrier properties are achievable by the incorporation of nanoclays into polyolefins. Additionally, it is significant that these benefits can be realized at clay concentrations consistent with those of common polymer additives, like stabilizers, clarifiers, and colorants.

N-Trimellitylimido-S-valine ( 3 ) was prepared by reaction of trimellitic anhydride ( 1 ) with S-valine ( 2 ) in acetic acid solution at refluxing temperature. This diacid was reacted with thionyl chloride and N -trimellitylimido-S-valine diacid chloride ( 4 ) was obtained in quantitative yield. The reaction of this diacid chloride with p -aminobenzoic acid was carried out in dry tetrahydrofurane and bis( p aminobenzoic acid)- N -trimellitylimido-S-valine ( 5 ) was obtained as a novel optically active amide-imide diacid monomer in high yield. The direct poly condensation of amide-imide diacid monomer with aromatic diamins such as 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ether, benzidine, 4,4'-diaminodiphenyl methane, 1,4- phenylene diamine and 2,5-diamino toluene was carried out in tosyl chloride/ pyridine/dimethylformamide system. The resulting novel optically active poly(amide-imide)s (PAIs) with inherent viscosities ranging from 0.24-0.76 dLg -1 , were obtained in good yield. All of these polymers were fully characterized with FTIR spectroscopy and specific rotation. Some elemental analysis, thermal properties and 1 H-NMR of these new optically active PAIs are also reported.

Novel photochromic polyesterimides (PEIs) with two different types of azobenzene units as side groups have been synthesized from 2,2’-{4-[(4- nitrophenyl)-azo} phenyl]iminobis(ethyl benzene-1,2-dicarboxylic acid anhydride-4- carboxylate) and diamines: 2,4-diamino-4’-methylazobenzene and 2,4-diamino-4’- (trifluoromethoxy)azobenzene. An analogous polyesterimide with one azobenzene group based on 1,3-phenylendiamine has been prepared to compare with these PEIs. Molecular structural characterization for these polymers has been achieved by FTIR, 1 H NMR and UV-Vis spectroscopy. These amorphous polyesterimides are thermally stable up to 260°C as follows from the thermogravimetric analysis (TGA). The glass transition temperatures (Tg) for the resulting polyimides have been determined from DSC thermograms and are in the range of 141-210°C. The irradiation with linearly polarized light of an Ar + laser results in the induction of optical anisotropy within the initially isotropic films. Light induced optical anisotropy in polymer films has been studied by examining the value of generated dichroism using Ar + laser (λ = 488 nm) and by holographic polarization grating recording performed at λ = 514.5 nm. The value of photoinduced dichroism is in the range of 0.15-0.26. The induction of dichroism and kinetics of grating inscription have been investigated in relation to the presence of the second type of azobenzene group in the polymer and its substitution.

Aggregation behavior of blend of poly( N -vinyl pyrrolidone) ( PVP ) and polystyrene having a sulfonic acid group at one end ( PSS ) in aqueous solution was investigated by dynamic and static light scattering (DLS, SLS) measurements and scanning electron microscopy (SEM). The angular dependence of apparent diffusion coefficients suggested that the PVP - PSS aggregate shows an anisotropic structure. Comparison of an experimental SLS profile with theoretical calculations of particle scattering functions indicated that the PVP - PSS aggregate formed rodlike structure with 1200 nm height and 20 nm cross-sectional radius. Corresponding results were obtained by SEM observations.

In this study the melt flow behavior of poly(butylene terephthalate)-clay nanocomposites produced by melt compounding was investigated. Four commercial organo-modified montmorillonites, differing mainly by the organic treatment used in the modification, were employed as nanometric fillers and blended with the poly(butylene terephthalate) (PBT) at two weight percentages each (6 and 9wt%). The process was carried out using a laboratory-scale twin-screw extruder at two different extrusion rates, in order to evaluate the effect of the shear rate during the process on microstructure and flow properties. In this regard, the nanocomposite samples were submitted to morphological analyses and rheological measurements in the dynamic regime. The effect of temperature on the flow behavior of the hybrids with respect to the neat PBT matrix was also investigated. The obtained data were related to the hybrid compositions and then to the chemical affinity between polymer and clay type. All the reported results have shown a gradual transition from a pseudo-Newtonian trend towards a pseudo-solid-like flow behavior with the increase of the clay loading and the dispersion/exfoliation level of the clay particles, due to the corresponding increase of the polymer-silicate interactions that slow the relaxation times of the PBT chains. Moreover, it was also evident that for the fillers having the higher affinity towards the PBT the nano-scale dispersion benefit from higher residence times, and therefore slower extrusion rates; on the contrary, for the fillers having poor interaction with the polymer, higher shear stress, and therefore higher extrusion rates, are needed to disrupt the clay tactoids in smaller particles. In the last part of the work, in order to verify if a relationship between flow properties and degree of exfoliation does actually exist, the rheological data were also processed using a simple semi-quantitative empirical method proposed in literature. The method failed for our systems, thus underlining the insufficiency of the rheological response alone in quantifying the exfoliation degree of an organoclay in the matrix.

The surface crystallization of three different polyhydroxy alkanoates (PHAs), poly(3-hydroxybutyrate) (PHB), PHB-co-5 weight percent 3-hydroxyvalerate (PHBV5), and PHB-co-12 weight percent 3- hydroxyvalerate (PHBV12), under different processing conditions is analyzed with depth profiling attenuated total reflection spectroscopy (ATR) and differential scanning calorimetry (DSC). The results of ATR indicate that there is a crystallinity distribution on the outer 2 microns thick surface layer. The degree of crystallinity in different penetration depths follows the order of 0.92μ > 0.41μ > 1.70μ for all three hot-pressed PHAs studied and the outer surfaces have a much greater crystallinity than the bulk. The surface crystallinity of specimens is in the order of PHB > PHBV5 > PHBV12 regardless of the different penetration depths analyzed which is consistent with the DSC results. It is also obtained that the effect of annealing in enhancing the crystallization of PHAs is more significant in the surface layer. The surface crystallinity of PHAs obtained after annealing follows the trend of Petri-dish side of solvent-cast PHB > hotpress PHB > air side of solvent-cast PHB > PHBV5 > PHBV12. The difference in crystallinity between the surface and the bulk of PHAs decreases with the addition of 3-hydroxyvalerate but increases after annealing. It is confirmed that the film forming method and the substrate contacted affect the surface crystalline state of PHAs which is attributed to the changes in crystallization conditions in the surface materials.

The influence of surfactant blend composition, organic solvent (oil) structure and cationic charge density (CCD) on stability of comonomer inverse microemulsions of acrylamide and [2-(acryloyloxy)ethyl]trimethylammonium chloride has been studied in order to obtain criteria for selecting comonomer inverse microemulsions before copolymerization resulting in copolymer inverse microemulsion useful as flocculants. Results show that optimum HLB can be explained by cohesive energy ratio theory and it increases with CCD; the higher the hydrophobic chain length of surfactants in surfactant blend, the lower the minimum surfactant blend concentrations (SBCm) needed to obtain stable inverse microemulsions; and linear organic solvents allow a decrease of the SBCm required for stabilizing comonomer inverse microemulsions.

The ion permeability of poly(p-xylylene) (PPX, parylene-N ® ) thin films was investigated using a cyclovoltammetric setup. Iron rods of different surface roughness were coated with PPX films of different thickness (140 - 700 nm) by vapour phase deposition (Gorham process). The presence of pinholes in PPX films deposited as described was analyzed by ion permeability according to cyclovoltammetric measurements. Current densities were directly related to the area of iron not covered by the polymer. It was found that films deposited on iron surfaces by the Gorham process showed significant ion permeability for film thicknesses below 500 nm and no permeability at all for films equal to or thicker than 700 nm, which indicated the absence of pinholes of PPX films of 700 nm thickness. Furthermore, films of 140 nm were deposited on iron surfaces of different roughness (the mean roughness was measured to be 10 2 nm, 10 3 nm and 10 5 nm). Current density increased by the increase in roughness, which confirmed that pinhole formation correlated with surface roughness.

A series of prototypical Co(II)-based pyridyl bis(imine) complexes {[2- (ArN=C(Me)) 2 C 5 H 3 N]CoCl 2 } (Ar = 2,6-C 6 H 3 Me 2 , 2,5-C 6 H 3 Me 2 , 2,4-C 6 H 3 Me 2 , 2,3- C 6 H 3 Me 2 ) bearing two methyl substituents on each imine aryl group are studied as precatalysts for the homopolymerization of 1,3-butadiene. They showed very high polymerization activities associated with ethylaluminum sesquichloride (EAS) as a cocatalyst. The Co(II) catalysts containing less hindered pyridyl bis(imine) ligands, say [2-(2,3-C 6 H 3 Me 2 N=C(Me)) 2 C 5 H 3 N]CoCl 2 complex, showed highest activity to give high molecular weight polymers. All catalysts yielded cis -1,4-polybutadienes up to 96.4% with cis -1,4 regular structure.

Catalyst fragmentation and polymer growth in the early stages of propylene polymerization has been investigated using different Ziegler-Natta catalysts. Polymerization was carried out in slurry under mild conditions and stopped at low yield. Scanning electron microscopy (SEM) has been used to characterize the surface and cross sectional morphology of polymer particles at different stages of particle growth. Different fragmentation behavior is observed, and it is found that the way that catalyst fragments in the early stages of polymerization is greatly influenced by the porosity of the catalyst. When a less porous catalyst was used, the resulting mass diffusion limitation causes layer-bylayer fragmentation, starting at the outer surface of the catalyst particle to the center. In contrast, for highly porous catalyst, monomer can easily penetrate into the pores of the catalyst / polymer particle. The polymer growing throughout the particle results in a coarse and instantaneous fragmentation.

Experimental results on work W(ε), heat Q(ε) and stored energy U(ε) of deformation for glassy polymers such as linear PS, PC, PMMA, Polyimid, amorphous PET, thermotropic aromatic polyesters, Vectra™ for example, crosslinked epoxy are presented. All the data was obtained by a deformation calorimetry technique. Loading and unloading of samples were performed at room temperature with strain rate έ = 10 -2 - 10 -4 sec -1 under uniaxial compression up to engineering strains of ε def = 40-50%. During straining all polymers accumulate an excess of the latent energy U(ε). Elastic fraction of the energy is released completely at sample unloading and only residual U res (ε) energy is conserved in samples. The latent energy U res (ε) grows up to ε def =20-25% and levels off then. Shapes of the U res (ε) curves are the same (S-shape) for all polymers. However, the saturation level is different for each polymer. The ratio U(ε)/W(ε) was also measured. It was found that at strains ε def < ε y (ε y - strain at the yield point) U(ε)/W(ε) ≈100%. I.e. all W is stored by sample in a form of U. The ratio decreases up to 60-30% for different polymers at higher strains. Release of the residual energy U res (DSC measurements) and strain ε res (thermally stimulated strain recovery technique) was measured for deformed and unloaded samples at heating. It was found that about 85-90% of U res stored by samples is released in glassy state of polymers (below T g ). The U res is related to a small fraction of ε res , only to 7-10%. The rest of U res and ε res are recovered at the softening (devitrification) interval, around T g . Computer modeling (molecular dynamics) of an isothermal shear deformation was performed for 2-dimentional two component atomic glass containing 500 Lennard-Jones particles of two different diameters. It was found that localized deformation events are of anelastic nature. The ε an appears at early deformation stage in a form of localized shear events (transformations). Such events are nucleated in a sample and merged and united at later deformation stages, when concentration of the events becomes high enough. Finally, merged transformations form kind of shear band crossing entire sample. On the basis of experimental data and computer modeling the deformation mechanism for glassy polymers is proposed. The first stage of the process is the nucleation of “the carriers of non-elastic strain”, anelastic shear transformations (ASTs). All these ASTs are energetically excited. The concentration of the ASTs is responsible for the amount of U res (ε) stored by a sample. It is suggested that such nucleation is the rate-controlling step in non-elastic deformation of any non-covalent glass. Saturation of the stored energy is defined by the reaching the steady state regime in carrier’s concentration. In this regime the rates of nucleation and termination (decrease of the stored local energy by AST) of carriers becomes equal. The termination proceeds spontaneously and easy (fast). The decrease of local energy of ASTs follows by local uncoiling of chains and by an appearance of new, extended chain conformers. However, such uncoiling is not the rate-controlling step for entire deformation process. Suggested mechanism very well describes all existing experimental facts. Deformation mechanisms for glasses seriously differ from that operating in rubbers and crystals.

Ab initio emulsion copolymerization of styrene with 2-hydroxyethyl methacrylate (HEMA) at weight ratios of the hydrophilic monomer of 1 and greater was investigated at various temperatures in dependence on the concentration of sodium dodecylsulfate (SDS) and potassium peroxodisulfate as emulsifier and initiator, respectively. Both the course of the polymerization and the latex properties are strongly influenced by the hydrophilic monomer. For instance, transparent or highly translucent latexes are obtained resembling the appearance of microemulsion latexes with polymer contents as high as 10 weight-% but at much lower surfactant concentration. Moreover, polymerization rate, average particle size, and particle morphology depend on the surfactant and initiator concentration, monomer feed composition, and polymerization temperature.

The thermoresponsive hydrogel microspheres were obtained by copolymerization of N- isopropylacrylamide (NIPAM) and 2-hydroxyethyl methacrylate (HEMA) crosslinked with N , N ’-methylenebisacrylamide (BIS). The hydrogel was then functionalized using 1-naphthyl glycidyl ether (NGE) to attach naphthyl chromophores, which absorb UV light and act as photosensitizers. The ability of the functionalized microspheres to photosensitize dechlorination reactions was confirmed using pentachlorophenol (PCP) as a model compound.

Functionalized polymer nanoparticles have been synthesized by emulsifier-free emulsion polymerization of styrene with amino-functionalized monomers. Two monomers were used: the well-known 2- aminoethylmethacrylate and a new monomer with a styrenic polymerizable function, 4-(2-aminoethylthio)methylstyrene. The latexes were characterized by gravimetry, dynamic light scattering and colorimetric titration in order to obtain the styrene conversion, the hydrodynamic diameter, the particle size distribution and the concentration of surface amino groups, respectively. Then, glycosydic molecules such as maltose, lactose, maltotriose and galactopyranosylethanal were covalently grafted to the nanoparticles by amidation or reductive amination.

Polyvinylpyrrolidone (PVP)/ZnO composite nanofibers were successfully prepared by a facile method called electrospinning technique. The synthetic strategy involved two steps: (1) Preparation of ZnO sol in ethanol solution. PVP molecules then added into the above sol and achieved the appropriate rheology for electrospinning; (2) Electrospun the above solution to obtain fibers of PVP/ZnO composites. Scanning electron microscopic (SEM) analysis of the composite nanofibers revealed network structures like a spider’s web. Transmission electron microscopy (TEM) showed small nanoparticles of the ZnO component with an average particle size in the range of 3 - 4 nm and a good dispersion. X-Ray diffraction results showed that a pure wurtzite phase was obtained in PVP fibers. XPS spectra proved that the Zn and O elements existed in PVP/ZnO composite nanofibers. FTIR and UV-vis spectroscopy were used to characterize the structure of PVP/ZnO composite nanofibers. The photoluminescence properties of the PVP/ZnO composite nanofibers were also investigated.

Polyoxymethylene (POM) was blended with various weight percentages of ethylene propylene diene terpolymer (EPDM) and ethylene vinyl acetate copolymer (EVA) separately in a twin screw extruder under optimum conditions. The mechanical properties of the blends such as tensile strength, impact strength and % elongation were measured. Increasing content of EPDM and EVA up to 7.5% increases the impact strength of POM. Addition of elastomer beyond 7.5% decreases the impact strength due to the poor adhesion between plastic and elastomer phase. POM/EPDM blends compatibilised with EVA showed improved impact strength. The present study reveals that the impact strength of POM can be improved by blending with EPDM and EVA. The incorporation of EVA as compatibiliser into POM/EPDM causes significant improvement in impact strength. Scanning electron microscopy (SEM) reveals enhanced adhesion of POM and EPDM in the presence of EVA up to the extent 5 parts per hundred of resin (phr) resulting in improved dispersion of the elastomer in the plastic matrix.

Chitin and chitosan are natural based non-toxic, biodegradable and biocompatible polymers and have been used in biomedical areas in the form of sutures, wound healing materials and artificial skin, and for the sustained release of drugs as well as in various industrial applications. However, practical use of these polymers has been mainly confined to the unmodified forms. Recently, there has been a growing interest in chemical modification of chitin and chitosan to improve their solubility and widen their applications. Among them, phosphorylated chitin and chitosan have attracted considerable interest because of their various advantages: anti-inflammatory property, ability to form metal complexes, blood compatibility and formation of anionic polyelectrolyte hydrogels. The purpose of this review is to take a closer look of different synthetic methods of phosphorylated chitin and chitosan and their potential applications in environmental, food, fuel cell, and biomedical fields. Based on current research and existing products, some new and futuristic approaches in this context area are discussed.

It was found that a comb-like complex consisting of poly[2-( N,N dimethylamino) ethyl acrylate] (PDAEA) and p -dodecylbenzene sulfonic acid (DBSA) formed mesomorphically ordered lamellar phase at room temperature where PDAEA and DBSA are in molten state. The lamellar phase shows optical anisotropy, although the individual components are always isotropic. In addition it is found that the optical anisotropy of the PDAEA-DBSA complex completely disappears with accompanying order-disorder transition of the lamellar morphology with elevating temperature.

The effects of blend composition on film formation is studied using the SSF and UV-visible (UVV) techniques. Latex blend films were prepared from mixtures of two types of particles in dispersion, one composed of a high-Tg (hard) pyrene (P) labeled polystyrene (PS) latex; the other a low-Tg (soft) poly(n-butyl acrylate) (BuA1). Twelve different blend films were prepared in various hard/soft latex compositions at room temperature and annealed at elevated temperatures above glass transition temperature (Tg) of polystyerene for 10 min. Fluorescence intensity (IP) from P was measured after each annealing step to monitor the stages of film formation. The evolution of transparency of latex films was monitored using photon transmission intensity, I tr . Film morphologies were examined by atomic force microscopy (AFM). The results showed that as the amount of hard component in the blend is decreased, a significant change occured in both IP and Itr curves at a certain critical weight fraction (50%wt) of PS hard latex. Above this fraction two distinct film formation stages, which are named as void closure and interdiffusion were seen in fluorescence data. However, below 50%wt PS no film formation stages were observed. Below this fraction, Itr data showed that phase separation process occurs between PS and BuA1 polymers. These results were also confirmed by AFM pictures. Film formation stages for 50-100%wt range of PS were modeled and related activation energies were calculated. There was no observable change in activation energies confirming that film formation behavior is not affected by varying the blend composition.

The influence of initiator concentration, specific flow rate of initiator addition (Q sp ), initial copolymerization temperature (Ti), aqueous phase pH and total comonomer concentration (TCC) on flocculating performance of latex particles of acrylamide and [2- (acryloyloxy)ethyl]trimethylammonium chloride copolymers with a cationic charge density of 40%, obtained by inverse microemulsion copolymerization by using a surfactant blend of Arlacel 83 and Softanol 90 as emulsifier and Rolling M-245, a mixture of n-decane and n-tetradecane in about 40/60 weight ratio, as oil phase, has been studied for high TCC, ranging from 28 to 34.5% (w/w). Comonomer inverse microemulsion copolymerizations were carried out in the semicontinuous mode by adding continuously an aqueous solution of sodium metabisulfite as initiator into stirred inverse comonomer microemulsions. Initiator concentration has a strong influence on viscosity, viscometric structuring degree (VSI) and average weight molar mass (M w ) of copolymers in the range from 5 to 25 g/L. Both viscosity and M w decrease with increasing initiator concentration. Best flocculating performance is obtained from 10 to 20 g/L, values at which VSI shows a minimum. Under the experimental conditions used, Qsp (153 to 310 mL/h/kg of comonomer), Ti (25 to 35ºC) and aqueous phase pH (2.5 to 4.5) have almost no influence on both viscosity and VSI and, hence, on flocculating performance. On the contrary, TCC has a slight influence on copolymer viscosity but a strong one on VSI which increases dramatically with TCC, being the worst flocculating performance obtained at the highest TCC studied (34.5% (w/w)). Flocculating performance results are explained in terms of copolymer structuring degree and collapsed state of copolymer chains inside latex particles as well as in terms of the composition drift with conversion.

Elution fractionations of broadly molar mass-distributed, hyperbranched poly(urea-urethane)s with OH- and Ph- end groups were carried out to obtain a number of macromolecular samples possessing different molar masses at the same chemical structure. The characterization of the polymers was performed by SEC, MALLS, 1 H-NMR, MALDI-TOF-MS and viscosity measurements. Modifications of the OH-end groups of the polymers were carried out. We observed a strong influence of the end groups on the solution behaviour of the hyperbranched samples. The molecular shape of the hyperbranched polymers in solution was compared to their linear analogue using the Kuhn-Mark-Houwink- Sakurada relationship. The calculated contraction factors between 0,15 and 0,7 depending on the molar masses correspond to a very compact structure of the modified branched polymers at high molar masses.

4-Vinylpyridine-divinylbenzene copolymer beads of ~0.3 mm in diameter were synthesized by suspension polymerization technique. The beads were made porous by dilution of the monomers with phthalate esters. The porosity was varied by changing the diluent, by varying the degree of dilution, and by varying the ratio of divinylbenzene in the monomers. Pore volume, surface area, and pore size distribution were determined by mercury penetration method, and densities of the dried copolymers were determined by a measuring cylinder and a balance. Statistical analysis of the data shows that the surface area and swelling coefficient in acetone can be estimated from the pore volume value with a reasonable good accuracy. Pore size distribution curves for the copolymers having pore volume in the range of 0.1 ml/g to 0.8 ml/g are shown. One can approximately estimate the pore size distribution if the pore volume is known. The pore volume can be estimated with a reasonable good accuracy from the density of the copolymers.

The unsaturated polyurethane (PU) was synthesized, characterized, and used in rubber compound. To study the effect of PU incorporation in the blend a systematic approach was used where PU was added to the natural rubber (NR), butadiene rubber (BR), and NR/BR blends. Different un-vulcanized and vulcanized compounds were characterized and the vulcanization process was investigated. It was observed that the synthesized PU was able to crosslink with the rubber compounds during the vulcanization process. The lowered temperature of melting indicated a better processability of the composites containing thermoplastic PU which melted at processing temperature, thereby allowing improvement in blend viscosity mold flow and to some extent in its homogeneity, although the mechanical properties such as hardness, tensile strength, modulus, and elongation at break did not differ significantly from the properties of elastomer blends without PU. The thermal stability of compounds with PU did not significantly worsen.

The relaxation processes occurring in slightly and well-entangled polydimetylsiloxane (PDMS) networks are investigated. Swelling experiments are performed in order to determine the sol fractions. The low-frequency linear rheology of the two types of networks reveal two significant relaxation processes, namely the reptation of linear species within the network and the arm withdrawal process of star arms in the sol fraction and of dangling single-chain ends attached to the network. The relaxation spectra are influenced by the stoichiometry to a large extent due to dynamic dilution effects caused by the change in the amount of dangling arms and solubles with stoichiometry. The star arm relaxation is suppressed by washing out the sol fraction which is seen as a clear example of the dynamic dilution effect arising from the small amount of non-reactive PDMS.

The synthesis of a series of bismaleimides based on diamines containing flexible units of variable length is presented. These structures were characterized by FTIR and NMR. The changes in spectra are dominated by the CH 2 stretching and deformation vibrational bands. The wavenumber of methylene provides a sensitive measure for the chain packing geometry. An attempt has been made to explain the odd-even effects at the molecular level on the basis of the article results. DSC was used to monitor the thermal properties of the samples. The melting points of the bismaleamic acids and bismaleimides are affected by odd-even effect. The reactivity of maleimide group was analyzed. Positions of signals in FTIR and NMR spectra show that BMI should be more stable as the chain length increase.

This project aims to develop and characterize a series of bismaleimide (BMI) polymers based on maleic anhydride and aliphatic-ether diamines. The effects of varying the chain length of aliphatic-ether diamines on the resultant bismaleimide systems were evaluated so that their suitability for microelectronics applications could be evaluated. The synthetic reaction and properties of the bismaleimide materials were investigated using Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), Thermo- Gravimetric Analysis (TGA), Dielectric Thermal Analysis (DEA) and rheometry. Results showed that thermal, dielectric and rheological properties were all affected by the main chain length of BMI. The magnitude of the dielectric constant at 100 kHz increases with the increasing chain length. The curing peak temperature, curing heat and degradation temperature of BMI, all decrease with the increasing chain length.

An economical strategy to prepare hyperbranched poly(sulfone-amine) modified β-cyclodextrins (HPSA-m-CDs) from natural β-cyclodextrin (β-CD) and other commercially available materials has been reported. The final product has many good properties of hyperbranched poly(sulfone-amine)s (good solubility, low viscosity etc.), while its inclusion ability can also be well kept. It is a feasible approach to prepare functionalized modified cyclodextrin at very low cost, and may have potential applications in the fields of catalysis, drug delivery, food additives, etc.

A three-step method was used to prepare a novel sulfone ether ester diamine. In the first step, reaction of 1,5-dihydroxy naphthalene with 4- nitrobenzoyl chloride afforded 5-hydroxy-1-naphthyl-4-nitrobenzoate (HNNB). By reduction of nitro group, an amino compound named 5-hydroxyl-1-naphthyl- 4-aminobenzoate (HNAB) was obtained. Reaction of HNAB (two moles) with bis (4-chlorophenyl) sulfone resulted in preparation of a novel sulfone ether ester diamine (SEED). Polycondensation reactions of the diamine with aromatic and aliphatic diacid chlorides led to preparation of new poly(sulfone ether ester amide)s. Conventional methods were used to characterize the structure of the monomer and polymers. Physical properties of the polymers were also studied. The polyamides were thermally stable and they showed improved solubility in dipolar aprotic solvents.

Liquid chromatography of polymers is traditionally a slow technique with analysis times of typically 30 min per sample. To adapt liquid chromatographic techniques to combinatorial materials research the sample throughput must be significantly increased. Preferably, the analysis time per sample is to be reduced to a few minutes. Short analysis times can be achieved using high resolution stationary phases, high flow rates, and fast gradients. The present work demonstrates that gradient HPLC of polymethacrylates can be accomplished in less than 2 min. The fast separation of poly(methyl methacrylate), poly( i -propyl methacrylate), poly( n- butyl methacrylate), poly( t butyl methacrylate), and poly( n -decyl methacrylate) is conducted on a short monolithic stationary phase using a flow rate of up to 7 mL/min. The optimization of the gradient is conducted by running a number of linear gradients and by simulating an optimum step gradient. Further modification of the simulated gradient results in the desired short analysis times.

New segmented polyurethanes (thermoplastic-elastomers) based on previously described hydroxytelechelic cis-1,4-polyisoprene (HTPI), miscellaneous isocyanates and chain extenders at various equivalent ratios were prepared by the classical one-shot method. The influence of the nature of isocyanate and chain extender, as well as their equivalent ratios, on the mechanical and thermal materials behavior was investigated. Thus, a comparative assessment of material properties was performed. Microphase separation of hard and soft segments was observed by DMTA, DSC and AFM. Moreover, according to Thermogravimetric Analysis (TGA), linear relationships depending on the isocyanate and chain extender nature were found between the weight loss (%) and the percentages of hard segments. A classification of thermal stability in terms of weight loss was established. With the aim of a thermo-mechanical comparative study, polyurethane elastomers based on HTPI and isocyanates without chain extender, were also synthesized.

A series of bismaleimide systems containing aliphatic backbone chain have been synthesized and investigated. Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), Thermomechanical analysis (TMA), rheometry and tensile test were used to characterize the thermal and mechanical properties. It was noted that backbone chain length and odd-even effect affected properties. As the chain length increases, the curing peak temperature, gel temperature of BMI all increase, but the melting point, glass transition and moisture absorption decrease. The melting points of BMI-3,5,7 reduced most significantly. The tensile properties were affected by odd even effect significantly. BMI-3,5,7 with odd number of carbons have less stress and strain than those of even ones.

Combination of Atom Transfer Radical Polymerization (ATRP) and Atom Transfer Radical Cross Coupling (ATRCC) processes as a route to prepare telechelic polymers was described. The concept is based on the activation of the dormant species at the chain ends of polystyrene (Br-PS-Br or PS-Br) prepared by ATRP and functional ATRP initiator (F-R-Br) in the absence of a monomer. Depending on the type of polystyrene used in the system, cross coupling of these active species gives α,ω-polystyrene and ω-polystyrene telechelics. Detailed investigations using a model system revealed that the efficiency of functionalization was not very high because of the self-coupling of the species derived from the polymer and functional initiator. However, the highest functionalization (X f =0.85) was achieved by introducing a small amount of styrene in the ATRCC.

Two series of polyurethanes (PUs) were synthesized from a low molecular weight diol - 4,4’-bis(6-hydroxyhexoxy)biphenyl (BH6), a high molecular weight diol - poly(1,6-hexylene adipate)diol (PHA) and 4,4’-methylenebis (cyclohexyl isocyanate) (HMDI) using two fractions of different trans,trans isomer content ( u T ), respectively: 16%, 46%. The effect of low molecular diol content ( u B ) in the total mass of the diols used for synthesis on properties of PUs was investigated by DSC, DTA, TGA, polarization microscopy, WAXS, DMTA and tensile testing. For segmented PUs microphase separation is observed and melting temperatures of hard segment (HS) microphases are almost constant within the series for u B ≥ 40%. The growth of hard segment content ( u HS ) induces rectilinear growth of crystallization enthalpy of HS microphases. PUs of u T = 46% show birefringence of HS microphases at uB B ≥ 40%. Glass transition temperatures of HS microphases shift towards lower values with a decrease of u B . PUs of u B = 80 and 100% are stiff, for 20 - 60% elastomeric properties are observed, and in absence of low molecular diol moieties ( u B = 0%) plastic behaviour is shown when stretched. Phase inversion is observed between u B B B = 60 and 80%. Thermal stability of PUs (by TGA and DTA) does not depend on u B and u T .

High molecular weight polyesters derived from pyridine-2,6-dicarboxylic acid and poly(ethylene glycol) have been synthesized under mild conditions (room temperature, atmospheric pressure) in the presence of picryl chloride and pyridine. Reaction conditions including solvent, trap agent, reaction time and amount of reagents were investigated using poly(ethylene glycol) 400 as dialcohol comonomer. Detailed analysis of the MALDI-TOF mass spectra of the obtained polyesters has revealed a predominant fraction of macrocycles for a picryl chloride/acid functions molar ratio lower than 1.5. The reaction yielded the most favourable results using 1.5 equivalents of picryl chloride with respect to the acid functions and 4-( N,N -dimethylamino)pyridine as HCl scavenger. The molecular weights of the polyesters at the peak maximum of the SEC trace are in the range of 4 800-80 000 depending on the nature of the comonomer poly(ethylene glycol). Syntheses of an aliphatic and aromatic polyester were also examined.

Novel hyperbranched polyesteramides have been synthesized from diethanolamine and maleic anhydride with ethylene glycol as a core monomer. No gelation occurred in the melt polymerization when diethanolamine and maleic anhydride were used in equimolar amount in the feed and when content of ethylene glycol was varied. Obtained products were soluble in water and in organic solvents such as NMF. The obtained polymers were characterized by using IR and NMR spectroscopies as well as GPC. It was suggested that the hyperbranched polyesteramides formed via a mechanism of a combination of esterification and addition reactions. The addition of a hydroxyl group to the - CH=CH- in maleic anhydride unit results in a formation of CH methine group. The ratio of -CH=CH- to CH in the polymers were estimated from 1 H NMR spectrum as 0.140, 0.155, 0.175, 0.190 and 0.204 for polymers P1 to P5 , respectively as the content of ethylene glycol charged decreased. The molecular weights and their polydispersities showed reverse dependences on the feed ratio of ethylene glycol to diethanolamine. The rheological properties of the polymers in aqueous solution were also examined. The polymers exhibit a steady increase of intrinsic viscosity with increasing molecular weight, and the Mark-Houwink exponent for these polymers is 0.26, which is much lower than 0.5 and suggested that these polymers possess a highly branched architecture. The polymer solutions showed a Newtonian behavior with steady shear viscosities independent of shear rate, which indicated the absence of a physical entanglement.

Double polymer networks (DNs) with poly(N-(3-sulfopropyl)-Nmethacroyloxyethyl- N,N-dimethylammonium betaine) component as a high density cross-linking agent were synthesized by thermoinitiated cross-linking polymerization. Good mechanical properties of the produced DNs were established. These, in combination with an excellent biocompatibility of polyzwitterions, open a possibility for wide biomedical applications of these materials. It is also shown that the mechanical properties could be controlled by the factors (cross-linking agent and monomer concentrations, temperature and time for the cross-linking polymerization, order of single network formation) influencing the junction point densities of the two single networks and on the microphase separation taking place during the formation of the second single network. Specific dipole-dipole interaction between polyzwitterion monomer units as a reason for this separation is a distinct peculiarity of poly(N-(3-sulfopropyl)-N-methacroyloxyethyl-N,Ndimethylammoniumbetaine)/ poly(acrylamide) double networks in comparison to poly(2-acrylamido-2-methylpropanesulfonic-acid)/poly(acrylamide) ones.

Polystyrene- block -polyisoprene with hydrogenated polyisoprene block (Shellvis 50) was sulfonated to a high degree (up to 42 mol% of styrene units) using acetyl sulfate as sulfonation agent in various chlorinated solvents. Membranes were prepared from the tetrahydrofuran solution of the sulfonated copolymer by casting. The membranes were characterized by conductivity and SAXS measurements.

Random and block copolymers containing styrene and mono n -alkyl itaconates with n = 12, 14, 16, 18 and 22 have been prepared by free radical polymerization and nitroxide-mediated radical polymerization. The molar fraction of the mono n -alkyl itaconate in block copolymers increased with increasing size of the alkyl group in the ester substituent. A calorimetric study of all these copolymers was performed. No glass transition (Tg) was observed in the temperature range - 30ºC-120ºC for random copolymers. Melting process attributed to crystalline order in the long side chains was observed for some copolymers depending on their composition and of the monoitaconate chain side length.

In this article, we synthesize a novel gelatin-based superabsorbent hydrogel via graft copolymerization of mixtures of acrylic acid (AA) and acrylamide (AAm) onto gelatin backbones. The polymerization reaction was carried out in an aqueous medium and in the presence of ammonium persulfate (APS) as an initiator and N , N' -methylene bisacrylamide (MBA) as a crosslinker. The hydrogel structures were confirmed by FTIR spectroscopy. The effect of grafting variables, i.e. concentration of MBA and APS, AA/AAm weight ratio, and reaction time and temperature, was systematically optimized to achieve a hydrogel with swelling capacity as high as possible. The swelling behavior of these absorbent polymers was also investigated in various salt solutions. Results indicated that the swelling capacity decreased with an increase in the ionic strength of the swelling medium. Furthermore, the swelling of superabsorbing hydrogels was examined in solutions with pH values ranging between 1.0 and 13.0. It showed a reversible pH-responsive behavior at pHs 2.0 and 7.0. This on-off switching behavior makes the synthesized hydrogels an excellent candidate for controlled delivery of bioactive agents. Finally, the swelling kinetics of the synthesized hydrogels with various particle sizes was preliminarily investigated.

In this paper, the composite latex particles with a polyacrylate (PA) core and a polydimethylsiloxane (PDMS) shell via 3-(methacryloxypropyl)- trimethoxy silane (MPS) as the medium to link the core and shell were prepared by semicontinuous seeded emulsion polymerization and were characterized by transmission electron microscopy (TEM), FT-IR, particle size analyzer and X-ray photoelectron spectroscopy (XPS). The TEM images indicated that the particles containing organic siloxane (D-40) displayed an evident core/shell structure. Additionally, the study by FT-IR and XPS also revealed that D4 could be grafted onto the surface of polyacrylate core because there appeared the characteristic peaks of Si-O-Si group and Si 2s and Si 2p in the spectra of FT-IR and XPS respectively. Besides, the atomic ratio of C/Si on the surface of the core/shell particles (D-40) was close to the ratio of C/Si in the latex of pure PDMS that could prove the PA particles were fully covered by PDMS and the properties of PDMS should be embodied in a maximal level. In order to testify the result, the surface properties of the films produced from the core/shell particles were also investigated by the static contact angle method. Compared with the copolymer of PA, the core/shell particles were more effective to create hydrophobic surface, so, the introduction of D4 was capable of obvious increase in water repellency.

Benzyl 9H-carbazole-9-carbodithioate (BCC) was synthesized and characterized. The single-crystal structure of BCC was first reported. The RAFT polymerizations of styrene and acrylates using BCC as the RAFT agent under conventional polymerization conditions were investigated. The results showed that the BCC was an effective RAFT agent for the polymerizations of styrene and acrylates. The well-controlled polymers were labelled with carbazole group, which was confirmed by 1 H NMR and the chain extension of the obtained polymer. Azo modified poly(methyl acrylate) (PMA) was synthesized through a postpolymerization azo-coupling scheme. The optical properties of obtained polymer were also characterized. The results showed that the carbazole group labelled polymer exhibited fluorescence and the azo polymer exhibited UV absorption behaviour in N,N-dimethyl formamide (DMF).

Nanocomposites containing poly(vinyl acetate) and montmorillonite (MMT) were prepared using a one-batch emulsion polymerization recipe, assisted by poly (vinylpyrrolidone). The relative clay concentration with respect to the other reaction partners influences drastically the morphological units in the end-products. For low [MMT], well-defined, spherical PVAc particles are formed. At the other extreme, for high [MMT], production of polymeric, water-swollen aggregates is favored. Depending on the MMT/PVP ratio, the clay will be dispersed in the final polymer matrix in variable forms, from individual platelets to agglomerates of reformed tactoids.

An iPP- g -St graft copolymer synthesized by free-radical initiated solidstate grafting polymerization of styrene in nascent spherical iPP granules was effectively fractionated by temperature gradient extraction fractionation (TGEF) into fractions of different styrene content. The fractions were characterized by FTIR, 1H-NMR, DSC, PLM and WAXD. The fraction extracted at room temperature (25 0 C) is homopolymer of styrene, and the fractions collected at 70, 90, and 105 0 C are iPP- g -St graft copolymer with decreasing degree of grafting. All the fractions of the grafting product contain a certain amount of styrene, meaning that almost all the iPP chains in the granules are accessible to the grafting monomer. The internal morphology of the iPP granules is highly porous, which enables the grafting monomer and the radicals to reach at each iPP chain during the polymerization. As styrene content of the iPP- g -St fraction increases, its crystallinity decreases, the size of iPP lamella decreases, and the crystalline morphology becomes more irregular.

The modification of poly(vinyl alcohol) (PVA) with glycidyl methacrylate (GMA) in DMSO catalyzed by TEMED is reported in this paper. PVA was dissolved in DMSO and reacted with GMA at 30 ºC in a closed vessel under N2 gas bubbling for 24 hours. The reaction was characterized by FTIR and NMR ( 1 H, 13 C/DEPT and HETCOR) spectroscopies. The reaction occurs by transesterification through the insertion of methacryloyl groups into PVA chains and probably with the formation of glycidol as a by-product. The degree of substitution (DS) that represents the number of methacryloyl groups inserted was determined through 1H NMR spectra based on the ratio between the averaged area due to the vinyl hydrogen from methacryloyl groups at δ ̣ 5.6 ppm and δ 6.0 ppm and the total area of the vinyl hydrogen and hydroxyl hydrogen of PVA. By use of response surface methodology the experimental conditions were optimized. The optimum conditions were 62 ºC with a reaction time of 6 hours. In these optimized conditions, the reactions using the molar ratios [-OH(PVA)/GMA] equal to 1/0.10, 1/0.25, 1/0.50, 1/0.75 and 1/1 were investigated. The response surface was based on the model DS= −19.70 + 6.09x10 −1 T +1.93 t − 3.89x10 −3 T 2 − 5.21x10 −2 t 2 − 2.14x10 −2 T * t, where T is the temperature (°C) and t the reaction time (hours). This model explained 99.20 % of the 99.64 % explainable statistical data. Using the optimized conditions, it is possible to produce a desired modified PVA, (or PVA-Ma), because DS raises linearly to the ratio [-OH(PVA)/GMA] up to 25 mol-% and the respective yield ranged from 83 to 92 %. It is difficult to obtain more than 50 mol-% substitution of PVA hydroxyl by methacryloyl groups even in these optimized conditions due to increased steric hindrance by the large number of the methacryloyl groups inserted into PVA.

The functional polystyrene, (Cl-PS) 2 -CHCOOCH 2 CH 2 OH (designated as XPSt and coded P2) was prepared by ATRP at 130 0 C using CuCl and bipyridine as catalysts, 2,2-dichloro acetate-ethylene glycol (DCAG) as multifunctional initiator and THF as solvent. 4-Nitoroaniline azomethine-4’ phenol (P1) as chromophores were covalently linked to the functional end groups of the polymer by using simple displacement reaction. The functional polystyrenes, namely XPSt (P2) and (PS) 2 -CHCOOCH 2 CH 2 OH, designated as X-PSt and coded P3 and their post-derivatives, namely, DXPSt (P4) and DX-PSt (P5) respectively were characterized by IR, NMR and UV spectroscopies, gel permeation chromatography (GPC) and thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), polarising optical microscopy (POM) and XRD studies. DSC showed that incorporation of chromophores in the side chains of polymers towards the polystyrene moiety increases the rigidity of the polymer and subsequently, its glass transition temperature; however the incorporation of side chain towards the alcoholic functional group decreases the glass transition temperature. The post derivatives do not play any significant role to increase the thermal stability (TGA). There was evidence for liquid crystalline properties in the resulting polymer derivative DXPSt (P4) as observed from POM study, which defines the alignment of chromophores into the polymers. The XRD study shows crystalline behaviour of the polymer derivative, P4. The polymer derivative, DXPSt (P5) does not show such behaviour and this may be due to the bonding of azomethine towards the short chain alcoholic telechelic alcoholic sides of the copolymer.

A new cellular fiber was obtained by a post-treatment of spun fibers. Cellular polymers such as poly(ethylene terephthalate) show great promise for different engineering applications due to their high density property. Recent study has shown that some high density cellular polymers possess long fatigue life and/or equivalent strengths as compared with commercial-type neat polymers. However, only few studies have focused on the process of cellular polymer fibers to date. In this paper, the effect on a cellular structure of cellular PET fibers (hereafter called “CPET fibers”) subjected to different forming processes is discussed. An ultra saturating gas method was used to fabricate the CPET fibers with different cell densities. Inert gas nitrogen (N 2 ) was saturated in PET fiber at high pressure to form a polymer/gas system. A pressure vessel was then discharged and polymer/gas solutions were foamed at a temperature controlled medium. The effect on the fiber’s cellular structure, particularly on the fiber cell density with different processing parameters such as pressure, saturation time, foaming temperature and time was investigated in detail. Experimental results showed that the cell density of the CPET fibers increased with increasing the pressure, saturation time, foaming temperature and time. The saturation time and pressure are key factors that affect the density of cells formed inside the CPET fibers. The foaming time however showed no substantial influence on the cell density of the fibers when held longer than 10s.

A simple high-performance liquid chromatographic method for the assay of ibuprofen and mefenamic acid in tablets is described. This method was developed by using self-prepared molecularly imprinted polymers (MIPs) as the stationary phase. MIPs are synthesized using non-covalent method by the free radical polymerization of template, functional monomer and an excess of crosslink monomers resulting in organic materials. The resulting bulk material was then ground into 25~44μm particles and packed into analytical columns. The effect of functional monomers/crosslinking ratio and the concentration of acetonitrile in the mobile phase were studied. Ibuprofen and mefenamic acid were efficiently resolved on the polymer. The retention time of ibuprofen and mefenamic acid were approximately 19.69±0.36min and 46.27±1.23min, respectively. Linearity was observed from 3.13-8.33g/l for ibuprofen and 0.3-0.9g/l for mefenamic acid, with the coefficients of determination (r 2 ) of 0.9977 and 0.9958. The limits of detection (LOD) of ibuprofen and mefenamic acid were found to be respectively 0.42g/l and 0.06g/l, while the limits of quantitation (LOQ) were 1.41g/l and 0.20g/l, respectively. The self-prepared MIP was successfully applied to the commercial tablet analysis and the result showed a good accuracy with -1.33 ~ -1.8% and -0.8 ~ +1.33% for ibuprofen and mefenamic acid.

The surface modification of polymeric biomaterials can be achieved by surface immobilization of bioactive molecules, increased hydrophilicity, and balanced hydrophilicity and hydrophobicity. Poly (L-Lactic Acid) (PLLA) is hydrophobic and possesses no reactive groups in the structure. In the present work, an effort has been made to blend PLLA with functionalized L-lactic acid / citric acid oligomer (PLCA) in order to improve the hydrophilicity of the PLLA. The compatibility of PLLA and PLCA was studied by using differential scanning calorimetry (DSC). The blends were also characterized for their water absorption, contact angle, tensile strength and hydrolytic degradation. The DSC results showed that PLLA/PLCA blends exhibited a single glass transition temperature (Tg), which lies in between that of PLLA and PLCA, thus asserting compatibility at the molecular level. The studies on water absorption, contact angle and hydrolytic degradation showed that addition of PLCA to PLLA enhanced the hydrophilicity of PLLA.

Hemicellulose-type polysaccharides were isolated from the delignified and ultrasonic irradiated sugarcane bagasse by a sequential two-step alkaline extraction. It was found that the successive extractions with 15% and 18% KOH for 2 h, 15% and 18% NaOH for 2 h, 8% and 10% KOH for 15 h, and with 8% and 10% NaOH for 15 h resulted in a total dissolution of 89.6%, 92.8%, 94.9%, and 97.3% of the original hemicelluloses, respectively. Sugar analysis revealed that xylose was the predominant sugar composition of all the hemicelluloses, comprising 57.4- 68.6% of the total sugars. Arabinose (12.3-18.4%) and glucose (10.8- 14.6%) appeared as the second and third major sugar constituents. Galactose (3.9-8.7%), uronic acids, mainly 4- O -methyl-glucuronic acid (2.7-5.8%), rhamnose (1.2-2.6%), and mannose (0.2-1.3%) were observed as minor constituents. The structural studies by 13 C-NMR spectroscopy showed that L-arabino (4- O -methyl-D-glucurono) xylans were the major constituents of the hemicellulosic polymers. Furthermore, the current results also showed that the four alkali-soluble hemicellulosic fractions, isolated during the first step treatment with relatively lower concentrations of alkalis, were more branched and acidic, and had larger molecular weights (M w , 23100-34500), but lower thermal stability than the other four alkali-soluble hemicellulosic preparations (M w , 21700-28700), extracted during the second stage treatment with relatively higher concentrations of alkalis.

The course of anionic hexano-6-lactam polymerization initiated with magnesium compounds differs in some parameters from that initiated with lactam alkali salts. This may be attributed to the coordination of magnesium compounds with functional groups on polymer chains. Supposed coordination effects were proved on model compounds of N-ethylacetamide and N-butyryl-hexano-6-lactam with magnesium bromide. Based on interpretation of Raman and NMR spectra, the interaction between magnesium bromide and both types of ligands as an electron donating coordination of carbonyl groups was proposed. N-butyryl-hexano-6-lactam is more distinctly coordinated to magnesium atom through the carbonyl group located in the cyclic constitution unit.

We have explored the influence of nematic order coupling on the swelling and phase diagram of polymer networks in nematogenic low molar weight LC solvent, in view of the increasing importance of such systems in advanced optical devices. Firstly, one isotropic polyacrylate network and one nematic sidechain polyacrylate network is prepared. Immersing these two networks in nematic LC solvent lead to the formation of well-defined polymer gels with LC solvents and allow us to establish the phase diagram of these relatively new materials in the concentration-temperature frame. Results were critically analysed as a function of temperature and network nature (isotropic or nematic). We demonstrate that in the case of gel made from an isotropic polymer network, the LC solvents fails to form a nematic phase inside the gel due to the lack of anisotropic coupling. Moreover, in that case the gel shrinks below T NI Solvent because of a strong “entropic” incompatibility between the isotropic flexible coils and the LC nematogens. However, the situation is drastically different in the case of LC side-chain network due to a strong coupling of the nematic order between the mesogens of the solvents and those of the polymer backbone. In that case, tremendous distortions appear in the phase-diagram, in which we especially emphasize the apparition of a stable nematic gel phase and a miscibility gap between T NI Solvent and T NI Gel . Finally, results are critically examined and compared to the few studies found in the literature.

Cellulose-based plastic films were prepared in homogeneous media with a range of lauroyl fatty acid attachments by ester formation, expressed as the degree of substitution (DS). The esters were cast to form films and their mechanical properties studied. This study showed a surprising relationship between DS and elastic modulus as well as DS and tensile strength, where a peak was observed at DS 2.4. The unexpected variation of static elastic modulus (E) was confirmed by dynamic mechanical analysis (DMA) and this trend was also observed for glass transition temperature (T g ). These results are discussed in relation to sample cohesion.

This paper is devoted to the preparation and characterization of new phenanthroline-triether copolymers with rotaxane architecture by reaction of complexes of α- or β- cyclodextrin and tri(ethylene glycol) ditosylate with 2,9-di(4-hydroxyphenyl)-1,10- phenanthroline, which is large enough to prevent dethreading of cyclodextrin molecules. Comparative 1 H-NMR analysis of tri(ethylene glycol) ditosylate complexes and of rotaxane copolymers evidenced the lower cyclodextrin content in rotaxane copolymers as compared to the calculated values. The rotaxane copolymers present bimodal molecular weight distributions attributed to the separation of the fractions with different content of cyclodextrin threaded on the copolymer chain. As evidenced by thermogravimetric analysis, the rotaxane copolymers show higher thermal stability than its non-complexed homologue.

This article describes simple preparation methods of poly(methyl methacrylate) (PMMA)/synthetic montmorillonite nanocomposites by single-step in situ polymerizations. Compatibility between PMMA and the silicate was ensured by an addition of (3-acrylamidepropyl) trimethylammonium chloride (AAPTMA). The work also compares how different synthetic routes, namely emulsion and solution polymerization, affect the structure as well as thermal and mechanical properties of obtained nanocomposites. The results of structural investigations clearly show, that both the techniques lead to intercalated nanocomposites, but emulsion polymerization allows more effective deflocculating and intercalating of the clay with acrylic copolymers. The addition of small amounts of layered silicates causes an increase in thermal stability and stiffness of the materials. It is demonstrated that at 5 wt. % of the filler, the temperature of 10 % weight loss was shifted up by nearly 50 K in comparison to the neat PMMA. In the same sample, the Young’s modulus of the material was found to be increased by 26 %.

The synthesis of poly(dihalophenylene oxide)s by thermal decomposition of Fe(II), Ce(III) and Ce(IV) phenolato complexes with pyridine as neutral ligands were achieved at different temperature ranges (140 o - 250 o C) with different time intervals (3 - 48 hr) via atom transfer rearrangement radical polymerization (ATRRP). The complexes were characterized by FTIR, DSC, UV-Visible, mass spectroscopy, magnetic susceptibility and elemental analyses. Structural analyses of polymers were performed by 1 H and 13 C-NMR, FTIR spectroscopic analyses, Tg by DSC and the molecular weights by viscometrical method. 1H-NMR spectra of polymers are quite similar in pattern except the relative intensities of two main peaks, all having branched structures. The lowest percent conversion values were observed for polymers synthesized from Fe(III) complexes compared to Ce(III) and Ce(IV) complexes. The glass transition temperature of the polymers were quite high indicating they are rigid polymers (162 o to 187 o C).

The synthesis and characterization of an optically active quinquethiophene monomer 3,3””-didodecyl-4’,3”’-di[(S)-(+)-2-methylbutyl]- 2,2’:5’,2”:5”,2”’:5”’,2””-quinquethiophene [(S)-(+)-DDDMBQT], bearing at the C-β positions of thiophene rings both linear C12 alkyl chain and chiral, enantiomerically pure, alkyl group is described. The polymerization of [(S)-(+)-DDDMBQT] by oxidative mechanism has been optimized in terms of yield of soluble polymer with high molecular weight. The obtained polymeric derivative displays enhanced conjugation extension with respect to similar poly(3-alkylthiophene)s reported in the literature and optical activity in the spectral region related to the chromophore absorptions when in the microaggregate state, indicative of the presence of supramolecular chiral conformations.

The polymerization of ethylene in the presence of vanadium catalysts supported on zeolite NaY, HY and charcoal was examined. The catalysts were prepared by the incipient wetness method and characterized by a variety of techniques to determine the oxidation state of the vanadium species inside the zeolite. In all the catalysts that were prepared vanadium is not in a single oxidation state. These catalysts were active in the polymerization of ethylene with activities of the order of magnitude 105 gPE/molV.[M].h for the zeolite catalysts and 103 gPE/molV.[M].h for the charcoal systems. No polymer could be obtained in the absence of alkylaluminum or aluminoxane in the experimental conditions used. The kinetics of ethylene polymerization reactions using the vanadium catalysts was studied. A kinetic model based on a proposed mechanism for these reactions was used to fit the experimental data. The application of this model resulted in very good fittings and the kinetic rate constants of each elementary step could be estimated. Since the polyethylene that was produced is closely bound to the zeolite catalysts, the thermal and mechanical properties of the PE/zeolite composites were measured, indicating that the presence of zeolite improved the mechanical properties of the polymers produced.

Poly(ether urethanes) based on aromatic diisocyanates and poly(propylene glycol) of different molecular weight and different hard segment content have been synthesised. The extent of the photooxidation of UV exposed samples has been evaluated by FTIR spectroscopy. The results proved that both the isocyanate chemical nature and polyol molecular weight play an important role in the photooxidation behaviour of these systems.

A series of poly(vinylidene fluoride)s (PVDFs) is synthesized in supercritical carbon dioxide (sc-CO 2 ). The influences of polymerization pressure, molecular weight distribution and H-H defect concentration on the crystallization of PVDF have been studied in combination with differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXRD) and Fourier transform infrared spectroscopy (FT-IR) measurements. The result shows that the morphology, molecular weights, polydispersity and head-to-head (H-H) defect concentrations of the PVDFs are affected by the reaction pressure and good solubility generated from sc-CO 2 . Especially, the sc-CO 2 polymerization has greatly improved the crystallization mode of the obtained PVDFs such as the complete degree of crystallinity, crystallinity and the crystal phase. This will create more comprehensive application fields for PVDF.

In previous studies, we discussed the use of water as an environmentally benign blowing agent for foaming of polystyrene beads, resulting in so-called WEPS, viz. water expandable polystyrene foam. Several grades of precursors to WEPS have been prepared by varying the water content and the molar mass, to control the melt strength of the polystyrene matrix. Additionally, we have used (endcapped) poly(2,6-dimethyl-1,4-phenylene ether) (PPE) to control both the meltviscosity and the glass transition temperature Tg. The advantage of using the blend PS/PPE is that the processing window for foaming is increased in view of the difference between the Tg and the boiling point of water. Using the novel WEPS route with some adjustments, for the first time a water expandable homogeneous blend of polystyrene and end-capped PPE was successfully obtained.

Different epoxy amine networks based on a mixture of diamine hardeners have been studied and their kinetic behaviour was modelled in order to understand the global and particular behaviour of each diamine in such blends. 4,4’-Diaminodiphenylsulfone (DDS) and 4,4’-methylenebis-(3-chloro-2,6- diethylaniline) (MCDEA) were used for this study by varying the DDS molar ratio from 0% to 50%. The determined kinetic model allowed us to calculate the composition for each diamine of the reactive epoxy-amine system in the whole range of epoxy conversions. Then the influence of 10% thermoplastic additive was checked and it was found to be negligible in the kinetic behaviour.

Part 2 of the study investigates morphologies of epoxy thermoset / thermoplastic blends obtained with formulations of the thermoset hardeners. The thermosetting matrices are composed of one epoxy resin crosslinked by a mixture of two aromatic diamine hardeners, namely MCDEA+DDS or MDEA+DDS (DDS is 4,4’-diaminodiphenylsulfone, MCDEA is 4,4’-methylenebis-(3-chloro-2,6- diethylaniline), MDEA is 4,4’-methylenebis-(2,6-diethylaniline). The blends are made at a fixed concentration of thermoplastic (poly(vinyl methyl ether), PVME, 10wt%) whereas three different cure temperatures are chosen and the matrix composition is varied by the ratio of DDS. DDS is a PVME-insoluble diamine whereas MDEA or MCDEA are PVME-soluble diamines. The domain size of the PVME nodules is tuned from a few micrometers down to sub micron sizes, typically between 50 and 80 nm. We attempt to explain this evolution thanks to the difference in the reactivity of the amines with the epoxy oligomer coupled to the difference in miscibility of each amine towards PVME. The kinetic study developed in Part 1 of this work is used to calculate the concentrations of each amine along the reaction time and their rate of incorporation in the polymer network. The latter parameter is shown to be the limiting factor for obtaining a nano phase separation.

Cardanol was extracted from technical Cashew Nut Shell Liquid (CNSL), a naturally occurring meta-substituted long chain phenol and oligomerized by heating at 140 °C. Products were characterized by rheology, infrared and 1 H NMR spectroscopy and thermogravimetric analysis (TGA). Increase in viscosity and the flow activation energy was found with increasing time of heating. The relative absorbance of double bond of the hydrocarbon chain decreased with time of heating and indicated that the oligomerization is taking place through the unsaturation of the side chain. Decrease in internal double bond as well as in vinyl bond, observed by 1 H NMR, pointed out to the participation of these two kinds of unsaturation as well as monoene, diene and triene. The oligomerization is a slow process. With 40 h of heating, the average molecular weight increases only by 46%. Great differences were found in TGA curves of cardanol with different times of oligomerization. Thermal stability increases with time of heating. The degree of oligomerization could be determined from relative mass loss of the first event of TG, or from flow activation energy.

A series of pH- and ionic sensitive semi-interpenetrating polymer network (semi-IPN) beads of chitosan (CS) and poly(vinyl pyrrolidone) (PVP) were prepared using glutaraldehyde as crosslinking agent and characterized for the release of coenzyme A (Co A). The swelling behavior of the semi-IPN beads and the influential factors, such as the component ratio of CS and PVP, the loaded amount of Co A, the pH and ionic strength of the release medium on Co A release were studied. The results showed that within 48 h the cumulative release rate of Co A decreased with Co A loading content, ionic strength increase or crosslinking time increase; when the weight ratios of CS to PVP in the drug-loaded beads were 100:0, 80:20, 60:40, 50:50, 40:60 and 20:80, the cumulative release rates of Co A at pH 2.1 solution were 95.2, 72.1, 73.2, 74.2, 86.5 and 80.1%, respectively, and they were 22.7, 30.1, 28.0, 33.1, 38.4 and 35.2% at pH 7.4 solution, respectively. All the results indicated that the CS/PVP semi-IPN beads were suitable for drug delivery systems.