Home Effect of post-compaction heating on characteristics of microcrystalline cellulose compacts
Article Open Access

Effect of post-compaction heating on characteristics of microcrystalline cellulose compacts

  • Shadi F. Gharaibeh EMAIL logo , Wasfy M. Obeidat and Nizar Al-Zoubi
Published/Copyright: May 30, 2022
Download Article (PDF)
Become an author with De Gruyter Brill
Submit Manuscript Author Information
e-Polymers
From the journal e-Polymers Volume 22 Issue 1

Abstract

Compacts of microcrystalline cellulose were prepared at applied compression pressures of 21, 32, 43, 53, and 64 MPa. Compacts were subjected to elevated temperatures of 125°C, 150°C, and 175°C according to a 5-min heating program. The effect of these thermal treatments on compact volumes, densities, porosities, tensile strengths, and weight loss was determined. There was no change in the volumes of the compacts due to thermal treatments in most of the conditions. However, the densities of the compacts decreased while the porosities increased as a consequence of weight loss. Moreover, there was no difference (p > 0.05) between the tensile strengths of the compacts without heat treatment and those subjected to heat treatment in most of the conditions. This was indicative of the preservation of the magnitude of the interparticulate bonds in the compacts. Weight loss of the compacts was affected by the heat treatment temperature and their porosities.

Keywords: tensile strength; microcrystalline cellulose; heat treatment; porosity; compact

1 Introduction

The compression of a powder results in particle deformation and possibly a consolidation into a compact. The characteristics of the formed compact are affected by the nature and properties of the compacted powder, moisture content, and applied compression pressure (1–3). In addition, post-compaction heating of tablets could influence their properties. Heating could induce the transition of amorphous components into a crystalline structure, leading to an increase in the tensile strength of a tablet (4–6). In addition, the evaporation of the moisture available in the tablet could enhance tensile strength by the crystallization of any dissolved components leading to the formation of additional interparticulate bridges (7,8). Therefore, a wet compression method was suggested in which a wet mass of lactose was compressed at relatively low pressure followed by an appropriate heat exposure to form rapidly disintegrating tablets (9). Moreover, tablet porosity and disintegration time could be influenced by post-compaction heating. It was found that tablet pore size, hardness, and disintegration time increased after heating erythritol and xylitol compacted mixtures at the melting point of xylitol (5). The increase in tablet hardness was attributed to the melting and post-heating crystallization of xylitol in the compacts. In addition, the heating of tablets containing a polymer above the glass transition temperature was shown to improve the polymer networking, thus enhancing the retardation of drug release (10,11).

Microcrystalline cellulose (MCC) powder is used as a binder in the manufacturing of tablets by direct compression. According to the United States Pharmacopeia-National Formulary, MCC contains less than 0.25% of its weight as water-soluble substances (12). MCC deforms under pressure predominantly by plastic behavior (2). It has also been suggested that the degree of crystallinity affects its compaction behavior. It was reported to have apparent crystallinity values in the range of 37–93% depending on the used X-ray method (13). Dry powder of MCC has been reported to have three glass transition temperatures at 132°C, 159°C, and 184°C (14). Moreover, it was found that adsorbed water affects the mechanical properties of compacts of MCC by acting as a plasticizer (1).

Several properties of MCC compacts were previously investigated. For example, it was found that compacts of MCC powder prepared at compression pressures between 8 and 106 MPa had tensile strength values in the range between 2 and 12 MPa depending upon the applied compression pressure and the used grade of MCC powder (15). In addition, it was found that the porosity under pressure of compacted MCC powder decreased as the compaction pressure increased. Moreover, the porosity under pressure was reported to reach below 0% at compaction pressures above 150 MPa. This was indicative of interparticulate changes along with increased density under pressure (16). Researchers also investigated the thermal properties of compacted MCC powder. It was found that MCC powder did not show morphological change in the crystal structure during heating to a temperature of 200°C. In addition, it was found that thermal conductivity and volumetric heat capacity of the compacts were dependent upon the relative density and temperature (17). To the best of the authors’ knowledge, no research prior to this study investigated the effect of post-compaction heating on the characteristics of MCC compacts.

The effect of post-compaction heating on the mechanical properties of lactose tablets has been previously investigated (8). The researchers subjected lactose tablets to 100°C for a period of 24 h. They noted that the tensile strength of the compacts increased markedly with thermal exposure. They attributed this increase in tensile strength to the transition of amorphous content of lactose to the crystalline form and to the evaporation of water that led to the crystallization of the dissolved materials, thus forming extra interparticulate bonding.

The aim of this study was to investigate the effects on compact volumes, densities, porosities, tensile strengths, and weight loss by subjecting MCC compacts prepared at various compression pressures to elevated temperatures for a relatively short period of time.

2 Materials and methods

2.1 Materials

MCC powder (Avicel PH-101 NF) was obtained from DuPont Nutrition USA, Inc. (USA). Magnesium stearate (magnesium octadecanoate) was purchased from Junsei Chemical Co., Ltd. (Japan). Ethanol (>96%) was obtained from Unicol Limited (Pakistan).

2.2 Characterization of MCC powder

Particle size analysis was performed using a Winner Laser Particle Size Analyzer model 2308C (Jinan Winner Particle Instrument Stock Co., Ltd, China). The analysis was performed using the dry mode. Three grams of the powder were placed in the sample area of the equipment. Multiple particle size distributions were collected for the sample during the run. An average of ten consequent distributions was used to determine the particle size (D10) at which 10% of the particle size distribution lies under, the median (D50), and the particle size (D90) at which 90% of the distribution lies under. The true density of the powder was determined using a gas pycnometer model Ultrapyc 1200e (Quantachrome Instruments, USA). Nitrogen was used as the purging gas. The true densities of three samples were determined and for each sample the result was the average of five runs. The result was presented as the average and standard deviation of the three samples.

Simultaneous thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were performed on a simultaneous thermal analyzer model STA 409 PC (Netzsch-Gerätebau GmbH, Germany). Five milligrams of each sample were weighed in an aluminum pan and placed in the sample carrier. The thermal analyses were performed under the continuous flow of nitrogen gas at a flow rate of 50 mL·min−1. The heating rate was set at 10 K·min−1 with a range between 30°C and 320°C. The TGA data were used to determine the percentage weight loss between the starting point and 175°C. The average and standard deviation of the results of triplicate samples were calculated. Moreover, samples of the powder without heat treatment and heat treated at 125°C, 150°C, and 175°C were analyzed using a multipurpose XRD system model Ultima IV (Rigaku Corporation, Japan). Continuous scanning was performed at a voltage of 40 kV and a current of 20 mA. The scanning range was obtained between 2θ equal to 5° and 80° at 0.02 step.

2.3 Preparation of compacts

Cylindrical compacts were prepared by compression of 0.50 g of MCC powder using a 15T manual hydraulic press (SCO Tech, Germany). The used die had a cavity diameter, outer diameter, and height equal to 14, 70, and 36 mm, respectively. The upper and lower punches were flat faced with lengths of 36 and 10 mm, respectively. The clearance between the punches and the die wall cavity was less than 0.1 mm. The die wall cavity was lubricated with a 5% magnesium stearate in ethanol suspension prior to each compression. Ethanol was allowed to evaporate leaving a layer of magnesium stearate on the die wall cavity before the die cavity was filled. This lubricant layer would ease the ejection of the compacts from the die cavity after compression. Applied compression pressures were 21, 32, 43, 53, and 64 MPa and the dwell time for each compression was 10 s. Five compacts were produced at each applied compression pressure which were kept at room temperature for 15–30 min before further analyses in order to match the time of the heat treatment procedure. Five other compacts were produced at each applied compression pressure for analyses at each of the heat treatment conditions.

2.4 Heat treatment

Heat treatment was performed using a moisture analyzer model BM-60 (Phoenix Instrument, Germany). The heat treatment conditions were programmed with the maximum temperature set at 125°C, 150°C, or 175°C. The heating procedure followed a 5-min heating program from which less than 30 s were needed to reach the maximum temperature. The temperature remained constant for the rest of 5 min. Following the heating program, the temperature dropped down to below 50°C in approximately 10–25 min depending on the maximum temperature setting. Five compacts prepared at each of the applied compression pressures were analyzed. Each compact was individually heat treated in the analyzer immediately after being produced. The weights of the samples before heat treatment (Wb) and at the end of the heat treatment program (Wh) were recorded. The percentage weight loss (% WL) was calculated using the following equation:

(1) % WL = Wb − Wh Wb × 100 %

Further analyses were performed immediately after the heat treatment procedure. Powder samples of MCC weighing about 0.5 g were also subjected to similar heat treatments at 125°C, 150°C, or 175°C for X-ray diffraction analysis. The % WL of the powder was calculated using Eq. 1.

2.5 Determination of compact dimensions, volumes, densities, and porosities

The diameters and thicknesses of five compacts without heat treatment and of five compacts before and after heat treatment prepared at each of the applied compression pressures were determined using an electronic digital caliper model WT 4171 (Worksite Tools & Equipment, China). The volumes were calculated from the measured dimensions of the cylindrical compacts. Compact density was determined by dividing the weight of the compact by its volume. Porosity (ε) was calculated according to the following equation:

(2) ε = 1 − ρ compact ρ true

where ρ compact is the density of the compact and ρ true is the true density of the powder.

2.6 Determination of Heckel’s yield pressure (P y )

The out-of-die Heckel analysis was performed on MCC compacts based on the following equation (18):

(3) ln 1 ε = K P + A

where P is the applied compression pressure, and K and A are constants. P y is equal to the reciprocal of K. Accordingly, the reciprocal of the slope of the fitted line of ln(1/ε) vs P is equal to P y .

2.7 Determination of compact tensile strengths

A tablet hardness tester model YD-3 (Biobase Group, China) was used to measure the crushing strengths (F) of five compacts prepared at each of the applied compression pressures. The following equation was applied to calculate the tensile strength (TS):

(4) TS = 2 F π D t

where D is the diameter of the compact and t is the thickness.

2.8 Statistical analyses

Results were statistically compared using the t-test add-on feature in Microsoft Excel. The mean values of the volumes, densities, and porosities of the compacts before and after heat treatments were compared using the two-tail paired t-test. An independent two tail t-test assuming equal variances was used to compare the mean values of the tensile strengths of compacts without heat treatment with those that were heat treated. A p-value less than 0.05 was considered a statistically significant difference in the performed tests.

3 Results and discussion

3.1 Characteristics of MCC powder

The true density of MCC powder was found to be equal to 1.597 ± 0.005 g·cm−3. According to the particle size analysis, the powder had D10 = 44 µm, D50 = 74 µm, and D90 = 103 µm. A noticeable percentage weight loss of the powder between the starting temperature and 175°C was observed on the TGA plot (Figure 1). This percentage weight loss was found to be equal to 5.61 ± 0.08%. In addition, there were no peaks on the DSC plot (Figure 1) that would indicate melting or decomposition of the powder at temperatures below 200°C. The diffractograms of MCC powder without heat treatment and heat treated at 125°C, 150°C, and 175°C (Figure 2) had peaks at similar 2 theta locations with similar intensities. This is indicative of the powder maintaining its crystallinity after the heat treatments. Crystallization from the amorphous form and polymorphic transitions were reported for cellulose when heat treated at elevated temperatures (19). However, such transitions were reported for heat treatments under pressure and for longer periods of time compared to our study. The slope of the fitted line of the out-of-die Heckel plot (Figure 3) was found to be equal to 0.013 (1/MPa). The yield pressure (P y ) was calculated to be equal to 77 MPa.

Figure 1 A representative plot of overlaid TGA-DSC analyses of MCC powder.
Figure 1

A representative plot of overlaid TGA-DSC analyses of MCC powder.

Figure 2 Diffractograms of MCC powder without heat treatment and heat treated at 125°C, 150°C, and 175°C.
Figure 2

Diffractograms of MCC powder without heat treatment and heat treated at 125°C, 150°C, and 175°C.

Figure 3 Out-of-die Heckel plot of MCC compacts.
Figure 3

Out-of-die Heckel plot of MCC compacts.

3.2 Effect of heat treatment on volumes, densities, and porosities of compacts

Statistical comparison between the mean values of the volumes of the compacts before and after heat treatment showed no significant difference (p > 0.05) in almost all the cases. Statistically significant differences were obtained when the compacts were heat treated at 125°C and the applied compression pressures were 43 MPa (p < 0.05) and 64 MPa (p < 0.05). In both of these cases, the differences between the averages of the volumes of the compacts before and after heat treatment were less than 1.6%. A change in volume after heat exposure was not observed for almost all of the heat-treated compacts. It seems like the distances between the consolidated particles did not change as a result of the heat treatment. However, there was a statistically significant difference (p < 0.05) between the mean values of the densities of the compacts before and after heat treatment in all of the cases. A decrease in the compact densities after heating was observed. This change in the densities was due to the compacts losing weight as a result of moisture evaporation during heat treatment while maintaining their volumes. In addition, there was a statistically significant difference (p < 0.05) between the mean values of the porosities of the compacts before and after heat treatment in all of the cases. An increase in porosity after heat treatment was observed. The increase in porosity was also due to the weight loss of the compacts as a result of the heat treatment. Therefore, the volume of the voids in any given compact relative to its volume increased. Figure 4 shows relations between the percentage increase in compact porosity after thermal exposure and compact thicknesses at different heat treatment temperatures. It can be seen that the highest percentage increase in porosity (10–12%) was obtained for the compacts with the smallest thicknesses. This increased effect of evacuation of pores was due to the smaller volumes of the compacts.

Figure 4 Relations between percentage increase in compact porosity and thickness of compacts at different heat treatment temperatures.
Figure 4

Relations between percentage increase in compact porosity and thickness of compacts at different heat treatment temperatures.

3.3 Effect of heat treatment on tensile strength of compacts

The tensile strengths of the compacts heat treated at 125°C, 150°C, and 175°C were comparable to those of the compacts without heat treatment for most of the applied compression pressures (Figure 5). The statistical comparison between the mean values of the tensile strengths of the compacts without heat treatment and those heat treated showed no significant difference (p > 0.05) for most of the heat treatment and applied compression pressure conditions. This finding indicates no change in the extent of interparticulate bonding. This is probably due to the preservation of the crystal structure of MCC (Figure 2) during the heat exposure and lack of any dissolved substance that might have crystallized during moisture evaporation. Nevertheless, statistical significance was obtained when the compacts were heat treated at 150°C and prepared at 53 MPa (p < 0.05) and 64 MPa (p < 0.05) with a decrease in the average tensile strength for the heat-treated compacts equal to 13% and 8%, respectively. Furthermore, statistical significance between the mean values of the tensile strength of compacts without heat treatment and those heat treated at 175°C was also obtained for compacts prepared at an applied compression pressure of 53 MPa (p < 0.05) with a decrease in the average tensile strength for the heat-treated compacts equal to 11%. The decrease in tensile strength after heat exposure is indicative of a reduction in the overall magnitude of interparticulate bonding. It is possible that the evolution of entrapped air in the compacts led to this finding. Researchers estimated that entrapped air in tablets could have pressure values that reach up to 20 times the atmospheric pressure (20). Upon heating, this pressure could increase to a point where it is sufficient to break the surrounding bonds to be released. This effect would be more pronounced at higher heat treatment temperatures (150°C and 175°C) and applied compression pressures (53 and 64 MPa).

Figure 5 Comparisons between the averages of the tensile strengths of compacts without heat treatment and compacts heat treated at 125°C, 150°C, and 175°C prepared at various applied compression pressures. Error bars represent + standard deviation, n = 5.
Figure 5

Comparisons between the averages of the tensile strengths of compacts without heat treatment and compacts heat treated at 125°C, 150°C, and 175°C prepared at various applied compression pressures. Error bars represent + standard deviation, n = 5.

3.4 Effect of heat treatment on % WL

The magnitude of the weight loss of MCC powder at the heat treatment temperature of 175°C (Table 1) was comparable to that obtained from the TGA analysis. However, it was found that the heat treatment temperature and porosity of compacts affected the magnitude of % WL (Figure 6 and Table 1). Some compacts had lower % WL compared to that of the powder. At the heat treatment of 125°C, the % WL of all compacts were smaller than that of the powder. This difference reached about 29% when compacts were prepared at 64 MPa. Compaction of the powder resulted in a less porous structure which increased the resistance to moisture escape. For heat treatments of 150°C and 175°C, some compacts had lower % WL while others had similar % WL compared to that of the powder heat treated at the same temperature (Figure 6 and Table 1). At the heat treatment of 150°C, the % WL of compacts decreased at lower values of porosities. The % WL of heat-treated compacts were lower than that of the powder by a magnitude of 18% when the compacts were prepared at 53 or 64 MPa. Additionally, compacts heat treated at 175°C and prepared at 53 MPa had a % WL that was 12% lower than that of the powder subjected to similar heat treatment conditions. Moreover, it was found that linear correlations between the % WL of the compacts and the heat treatment temperature can be made (R 2 > 0.91) for the compacts prepared at each of the different applied compression pressures (Figure 7). Compacts were heated in the analyzer which utilizes a heating element located above the sample in the chamber. This element heats up to the designated temperatures for the required period (5 min). The extent of weight loss is expected to depend upon the amount of heat transferred through the compact and the ability of moisture to escape through the porous structure during the treatment time. Compacts prepared at higher compression pressures are expected to have improved heat flow due to smaller thicknesses and lower porosities leading to higher thermal conductivity (17,21). On the other hand, these compacts could offer higher resistance for the moisture to escape. Figure 8 shows the relation between % WL normalized with compact thickness (i.e., % WL/t) and compact porosities before heat treatment. A trend of increased magnitude of % WL/t as the porosity decreased can be seen. Therefore, a combination of factors such as the heat treatment temperature, thermal conductivity of the compact, compact thickness, and resistance to moisture escape affected the magnitude of % WL.

Table 1

Averages of % WL of MCC powder at different heat treatment temperatures, n = 5

Heat treatment temperature % WL (%) Standard deviation
125°C 5.20 0.14
150°C 5.27 0.20
175°C 5.56 0.31
Figure 6 Relations between average values of % WL of compacts and compact porosity before heat treatment at different heat treatment temperatures. Error bars represent ±standard deviation, n = 5.
Figure 6

Relations between average values of % WL of compacts and compact porosity before heat treatment at different heat treatment temperatures. Error bars represent ±standard deviation, n = 5.

Figure 7 Relations between average values of % WL of compacts and heat treatment temperature at the applied compression pressures of 21, 32, 43, 53, and 64 MPa.
Figure 7

Relations between average values of % WL of compacts and heat treatment temperature at the applied compression pressures of 21, 32, 43, 53, and 64 MPa.

Figure 8 Relations between average values of % WL/t of compacts and compact porosity before heat treatment at different heat treatment temperatures. Error bars represent ± standard deviation, n = 5.
Figure 8

Relations between average values of % WL/t of compacts and compact porosity before heat treatment at different heat treatment temperatures. Error bars represent ± standard deviation, n = 5.

4 Conclusion

Heat treatment of compacts of MCC at 125°C, 150°C, and 175°C did not significantly affect their volumes in almost all of the applied compression pressure and heat treatment conditions. However, the densities of the compacts decreased while porosities increased due to weight loss associated with the heat treatments. In addition, the tensile strengths of the compacts did not significantly change for most of the heat treatment and applied compression pressure conditions. Therefore, the interparticulate bonding in the compacts was not affected under most of the conditions. Finally, a combination of factors resulting from both the applied compression pressure and heat treatment temperature affected the magnitude of weight loss of the compacts.

tel: +962-79-6302889, fax: +962-2-6350520

Acknowledgment

The authors would like to thank DuPont Nutrition USA, Inc. (USA) for the kind donation of Avicel PH-101 powder that was used in this study.

  1. Funding information: Authors state no funding involved.

  2. Author contributions: Shadi F. Gharaibeh: conceptualization, data curation, formal analysis, investigation, methodology, resources, supervision, writing – original draft; Wasfy Obeidat: data curation, investigation, methodology, resources, writing – review and editing; Nizar Al-Zoubi: data curation, investigation, methodology, resources, writing – review and editing.

  3. Conflict of interest: Authors state no conflict of interest.

  4. Data availability statement: Data generated during this work will be provided upon request.

References

(1) Amidon GE, Houghton ME. The effect of moisture on the mechanical and powder flow properties of microcrystalline cellulose. Pharm Res. 1995;12:923–9. 10.1023/A:1016233725612.Search in Google Scholar

(2) Doelker E. Comparative compaction properties of various microcrystalline cellulose types and generic products. Drug Dev Ind Pharm. 1993;19:2399–471. 10.3109/03639049309047196.Search in Google Scholar

(3) Wray PE. The physics of tablet compaction revisited. Drug Dev Ind Pharm. 1992;18:627–58. 10.3109/03639049209058556.Search in Google Scholar

(4) Alderborn G, Ahlneck C. Moisture adsorption and tabletting. III. Effect on tablet strength-post compaction storage time profiles. Int J Pharm. 1991;73:249–58. 10.1016/0378-5173(91)90417-M.Search in Google Scholar

(5) Kuno Y, Kojima M, Ando S, Nakagami H. Evaluation of rapidly disintegrating tablets manufactured by phase transition of sugar alcohols. J Control Rel. 2005;105:16–22. 10.1016/j.jconrel.2005.01.018.Search in Google Scholar PubMed

(6) Sebhatu T, Elamin AA, Ahlneck C. Effect of moisture sorption on tabletting characteristics of spray dried (15% amorphous) lactose. Pharm Res. 1994;11:1233–8. 10.1023/A:1018973923831.Search in Google Scholar

(7) Chowhan ZT. Role of binders in moisture-induced hardness increase in compressed tablets and its effect on in vitro disintegration and dissolution. J Pharm Sci. 1980;69:1–4. 10.1002/jps.2600690102.Search in Google Scholar PubMed

(8) Csobán Z, Kállai-Szabó B, Kállai-Szabó N, Sebe I, Gordon P, Antal I. Improvement of mechanical properties of pellet containing tablets by thermal treatment. Int J Pharm. 2015;496:489–96. 10.1016/j.ijpharm.2015.10.040. Cited: in: PMID: 26475969.Search in Google Scholar PubMed

(9) Bi Y, Yonezawa Y, Sunada H. Rapidly disintegrating tablets prepared by the wet compression method: mechanism and optimization. J Pharm Sci. 1999;88:1004–10. 10.1021/js990061z.Search in Google Scholar PubMed

(10) Azarmi S, Ghaffari F, Löbenberg R, Nokhodchi A. Mechanistic evaluation of the effect of thermal-treating on Eudragit RS matrices. Il Farmaco. 2005;60:925–30. 10.1016/j.farmac.2005.07.009.Search in Google Scholar PubMed

(11) Omelczuk MO, McGinity JW. The influence of thermal treatment on the physical-mechanical and dissolution properties of tablets containing poly(DL-lactic acid). Pharm Res. 1993;10:542–8. 10.1023/A:1018993818206.Search in Google Scholar

(12) United States Pharmacopeia 42-National Formulary 37. Rockville, MD: The United States Pharmacopeial Convention, Inc.; 2019.Search in Google Scholar

(13) Terinte N, Ibbett R, Schuster K. Overview on native cellulose and microcrystalline cellulose I structure studied by X-ray diffraction (WAXD): comparison between measurement techniques. Lenzing Berichte. 2011;89:118–31.Search in Google Scholar

(14) Picker KM, Hoag SW. Characterization of the thermal properties of microcrystalline cellulose by modulated temperature differential scanning calorimetry. J Pharm Sci. 2002;91:342–9. 10.1002/jps.10018.Search in Google Scholar

(15) Kothari SH, Kumar V, Banker GS. Comparative evaluations of powder and mechanical properties of low crystallinity celluloses, microcrystalline celluloses, and powdered celluloses. Int J Pharm. 2002;232:69–80. 10.1016/S0378-5173(01)00909-7.Search in Google Scholar

(16) van Veen B, Bolhuis GK, Wu YS, Zuurman K, Frijlink HW. Compaction mechanism and tablet strength of unlubricated and lubricated (silicified) microcrystalline cellulose. Eur J Pharm Biopharm. 2005;59:133–8. 10.1016/j.ejpb.2004.05.009.Search in Google Scholar

(17) Krok A, Vitorino N, Zhang J, Frade JR, Wu C-Y. Thermal properties of compacted pharmaceutical excipients. Int J Pharm. 2017;534:119–27. 10.1016/j.ijpharm.2017.10.018.Search in Google Scholar

(18) Heckel RW. Density–pressure relationships in powder compaction. T Metall Soc AIME. 1961;221:671–5.Search in Google Scholar

(19) Atalla RH, Ellis JD, Schroeder LR. Some effects of elevated temperatures on the structure of cellulose and its transformation. J Wood Chem Technol. 1984;4:465–82. 10.1080/02773818408070662.Search in Google Scholar

(20) Zavaliangos A, Katz JM, Daurio D, Johnson M, Pirjanian A, Alvarez-Nunez F. Prediction of air entrapment in tableting: an approximate solution. J Pharm Sci. 2017;106:3604–12. 10.1016/j.xphs.2017.09.001.Search in Google Scholar

(21) Tsotsas E, Martin H. Thermal conductivity of packed beds: a review. Chem Eng Process Process Intensif. 1987;22:19–37. 10.1016/0255-2701(87)80025-9.Search in Google Scholar
Received: 2022-03-03
Revised: 2022-04-24
Accepted: 2022-05-03
Published Online: 2022-05-30

© 2022 Shadi F. Gharaibeh et al., published by De Gruyter

This work is licensed under the Creative Commons Attribution 4.0 International License.

Articles in the same Issue

  1. Research Articles
  2. The effect of isothermal crystallization on mechanical properties of poly(ethylene 2,5-furandicarboxylate)
  3. The effect of different structural designs on impact resistance to carbon fiber foam sandwich structures
  4. Hyper-crosslinked polymers with controlled multiscale porosity for effective removal of benzene from cigarette smoke
  5. The HDPE composites reinforced with waste hybrid PET/cotton fibers modified with the synthesized modifier
  6. Effect of polyurethane/polyvinyl alcohol coating on mechanical properties of polyester harness cord
  7. Fabrication of flexible conductive silk fibroin/polythiophene membrane and its properties
  8. Development, characterization, and in vitro evaluation of adhesive fibrous mat for mucosal propranolol delivery
  9. Fused deposition modeling of polypropylene-aluminium silicate dihydrate microcomposites
  10. Preparation of highly water-resistant wood adhesives using ECH as a crosslinking agent
  11. Chitosan-based antioxidant films incorporated with root extract of Aralia continentalis Kitagawa for active food packaging applications
  12. Molecular dynamics simulation of nonisothermal crystallization of a single polyethylene chain and short polyethylene chains based on OPLS force field
  13. Synthesis and properties of polyurethane acrylate oligomer based on polycaprolactone diol
  14. Preparation and electroactuation of water-based polyurethane-based polyaniline conductive composites
  15. Rapeseed oil gallate-amide-urethane coating material: Synthesis and evaluation of coating properties
  16. Synthesis and properties of tetrazole-containing polyelectrolytes based on chitosan, starch, and arabinogalactan
  17. Preparation and properties of natural rubber composite with CoFe2O4-immobilized biomass carbon
  18. A lightweight polyurethane-carbon microsphere composite foam for electromagnetic shielding
  19. Effects of chitosan and Tween 80 addition on the properties of nanofiber mat through the electrospinning
  20. Effects of grafting and long-chain branching structures on rheological behavior, crystallization properties, foaming performance, and mechanical properties of polyamide 6
  21. Study on the interfacial interaction between ammonium perchlorate and hydroxyl-terminated polybutadiene in solid propellants by molecular dynamics simulation
  22. Study on the self-assembly of aromatic antimicrobial peptides based on different PAF26 peptide sequences
  23. Effects of high polyamic acid content and curing process on properties of epoxy resins
  24. Experiment and analysis of mechanical properties of carbon fiber composite laminates under impact compression
  25. A machine learning investigation of low-density polylactide batch foams
  26. A comparison study of hyaluronic acid hydrogel exquisite micropatterns with photolithography and light-cured inkjet printing methods
  27. Multifunctional nanoparticles for targeted delivery of apoptin plasmid in cancer treatment
  28. Thermal stability, mechanical, and optical properties of novel RTV silicone rubbers using octa(dimethylethoxysiloxy)-POSS as a cross-linker
  29. Preparation and applications of hydrophilic quaternary ammonium salt type polymeric antistatic agents
  30. Coefficient of thermal expansion and mechanical properties of modified fiber-reinforced boron phenolic composites
  31. Synergistic effects of PEG middle-blocks and talcum on crystallizability and thermomechanical properties of flexible PLLA-b-PEG-b-PLLA bioplastic
  32. A poly(amidoxime)-modified MOF macroporous membrane for high-efficient uranium extraction from seawater
  33. Simultaneously enhance the fire safety and mechanical properties of PLA by incorporating a cyclophosphazene-based flame retardant
  34. Fabrication of two multifunctional phosphorus–nitrogen flame retardants toward improving the fire safety of epoxy resin
  35. The role of natural rubber endogenous proteins in promoting the formation of vulcanization networks
  36. The impact of viscoelastic nanofluids on the oil droplet remobilization in porous media: An experimental approach
  37. A wood-mimetic porous MXene/gelatin hydrogel for electric field/sunlight bi-enhanced uranium adsorption
  38. Fabrication of functional polyester fibers by sputter deposition with stainless steel
  39. Facile synthesis of core–shell structured magnetic Fe3O4@SiO2@Au molecularly imprinted polymers for high effective extraction and determination of 4-methylmethcathinone in human urine samples
  40. Interfacial structure and properties of isotactic polybutene-1/polyethylene blends
  41. Toward long-live ceramic on ceramic hip joints: In vitro investigation of squeaking of coated hip joint with layer-by-layer reinforced PVA coatings
  42. Effect of post-compaction heating on characteristics of microcrystalline cellulose compacts
  43. Polyurethane-based retanning agents with antimicrobial properties
  44. Preparation of polyamide 12 powder for additive manufacturing applications via thermally induced phase separation
  45. Polyvinyl alcohol/gum Arabic hydrogel preparation and cytotoxicity for wound healing improvement
  46. Synthesis and properties of PI composite films using carbon quantum dots as fillers
  47. Effect of phenyltrimethoxysilane coupling agent (A153) on simultaneously improving mechanical, electrical, and processing properties of ultra-high-filled polypropylene composites
  48. High-temperature behavior of silicone rubber composite with boron oxide/calcium silicate
  49. Lipid nanodiscs of poly(styrene-alt-maleic acid) to enhance plant antioxidant extraction
  50. Study on composting and seawater degradation properties of diethylene glycol-modified poly(butylene succinate) copolyesters
  51. A ternary hybrid nucleating agent for isotropic polypropylene: Preparation, characterization, and application
  52. Facile synthesis of a triazine-based porous organic polymer containing thiophene units for effective loading and releasing of temozolomide
  53. Preparation and performance of retention and drainage aid made of cationic spherical polyelectrolyte brushes
  54. Preparation and properties of nano-TiO2-modified photosensitive materials for 3D printing
  55. Mechanical properties and thermal analysis of graphene nanoplatelets reinforced polyimine composites
  56. Preparation and in vitro biocompatibility of PBAT and chitosan composites for novel biodegradable cardiac occluders
  57. Fabrication of biodegradable nanofibers via melt extrusion of immiscible blends
  58. Epoxy/melamine polyphosphate modified silicon carbide composites: Thermal conductivity and flame retardancy analyses
  59. Effect of dispersibility of graphene nanoplatelets on the properties of natural rubber latex composites using sodium dodecyl sulfate
  60. Preparation of PEEK-NH2/graphene network structured nanocomposites with high electrical conductivity
  61. Preparation and evaluation of high-performance modified alkyd resins based on 1,3,5-tris-(2-hydroxyethyl)cyanuric acid and study of their anticorrosive properties for surface coating applications
  62. A novel defect generation model based on two-stage GAN
  63. Thermally conductive h-BN/EHTPB/epoxy composites with enhanced toughness for on-board traction transformers
  64. Conformations and dynamic behaviors of confined wormlike chains in a pressure-driven flow
  65. Mechanical properties of epoxy resin toughened with cornstarch
  66. Optoelectronic investigation and spectroscopic characteristics of polyamide-66 polymer
  67. Novel bridged polysilsesquioxane aerogels with great mechanical properties and hydrophobicity
  68. Zeolitic imidazolate frameworks dispersed in waterborne epoxy resin to improve the anticorrosion performance of the coatings
  69. Fabrication of silver ions aramid fibers and polyethylene composites with excellent antibacterial and mechanical properties
  70. Thermal stability and optical properties of radiation-induced grafting of methyl methacrylate onto low-density polyethylene in a solvent system containing pyridine
  71. Preparation and permeation recognition mechanism of Cr(vi) ion-imprinted composite membranes
  72. Oxidized hyaluronic acid/adipic acid dihydrazide hydrogel as cell microcarriers for tissue regeneration applications
  73. Study of the phase-transition behavior of (AB)3 type star polystyrene-block-poly(n-butylacrylate) copolymers by the combination of rheology and SAXS
  74. A new insight into the reaction mechanism in preparation of poly(phenylene sulfide)
  75. Modified kaolin hydrogel for Cu2+ adsorption
  76. Thyme/garlic essential oils loaded chitosan–alginate nanocomposite: Characterization and antibacterial activities
  77. Thermal and mechanical properties of poly(lactic acid)/poly(butylene adipate-co-terephthalate)/calcium carbonate composite with single continuous morphology
  78. Review Articles
  79. The use of chitosan as a skin-regeneration agent in burns injuries: A review
  80. State of the art of geopolymers: A review
  81. Mechanical, thermal, and tribological characterization of bio-polymeric composites: A comprehensive review
  82. The influence of ionic liquid pretreatment on the physicomechanical properties of polymer biocomposites: A mini-review
  83. Influence of filler material on properties of fiber-reinforced polymer composites: A review
  84. Rapid Communications
  85. Pressure-induced flow processing behind the superior mechanical properties and heat-resistance performance of poly(butylene succinate)
  86. RAFT polymerization-induced self-assembly of semifluorinated liquid-crystalline block copolymers
  87. RAFT polymerization-induced self-assembly of poly(ionic liquids) in ethanol
  88. Topical Issue: Recent advances in smart polymers and their composites: Fundamentals and applications (Guest Editors: Shaohua Jiang and Chunxin Ma)
  89. Fabrication of PANI-modified PVDF nanofibrous yarn for pH sensor
  90. Shape memory polymer/graphene nanocomposites: State-of-the-art
  91. Recent advances in dynamic covalent bond-based shape memory polymers
  92. Construction of esterase-responsive hyperbranched polyprodrug micelles and their antitumor activity in vitro
  93. Regenerable bacterial killing–releasing ultrathin smart hydrogel surfaces modified with zwitterionic polymer brushes
https://doi.org/10.1515/epoly-2022-0049
Keywords for this article
tensile strength; microcrystalline cellulose; heat treatment; porosity; compact
Creative Commons
BY 4.0

Articles in the same Issue

  1. Research Articles
  2. The effect of isothermal crystallization on mechanical properties of poly(ethylene 2,5-furandicarboxylate)
  3. The effect of different structural designs on impact resistance to carbon fiber foam sandwich structures
  4. Hyper-crosslinked polymers with controlled multiscale porosity for effective removal of benzene from cigarette smoke
  5. The HDPE composites reinforced with waste hybrid PET/cotton fibers modified with the synthesized modifier
  6. Effect of polyurethane/polyvinyl alcohol coating on mechanical properties of polyester harness cord
  7. Fabrication of flexible conductive silk fibroin/polythiophene membrane and its properties
  8. Development, characterization, and in vitro evaluation of adhesive fibrous mat for mucosal propranolol delivery
  9. Fused deposition modeling of polypropylene-aluminium silicate dihydrate microcomposites
  10. Preparation of highly water-resistant wood adhesives using ECH as a crosslinking agent
  11. Chitosan-based antioxidant films incorporated with root extract of Aralia continentalis Kitagawa for active food packaging applications
  12. Molecular dynamics simulation of nonisothermal crystallization of a single polyethylene chain and short polyethylene chains based on OPLS force field
  13. Synthesis and properties of polyurethane acrylate oligomer based on polycaprolactone diol
  14. Preparation and electroactuation of water-based polyurethane-based polyaniline conductive composites
  15. Rapeseed oil gallate-amide-urethane coating material: Synthesis and evaluation of coating properties
  16. Synthesis and properties of tetrazole-containing polyelectrolytes based on chitosan, starch, and arabinogalactan
  17. Preparation and properties of natural rubber composite with CoFe2O4-immobilized biomass carbon
  18. A lightweight polyurethane-carbon microsphere composite foam for electromagnetic shielding
  19. Effects of chitosan and Tween 80 addition on the properties of nanofiber mat through the electrospinning
  20. Effects of grafting and long-chain branching structures on rheological behavior, crystallization properties, foaming performance, and mechanical properties of polyamide 6
  21. Study on the interfacial interaction between ammonium perchlorate and hydroxyl-terminated polybutadiene in solid propellants by molecular dynamics simulation
  22. Study on the self-assembly of aromatic antimicrobial peptides based on different PAF26 peptide sequences
  23. Effects of high polyamic acid content and curing process on properties of epoxy resins
  24. Experiment and analysis of mechanical properties of carbon fiber composite laminates under impact compression
  25. A machine learning investigation of low-density polylactide batch foams
  26. A comparison study of hyaluronic acid hydrogel exquisite micropatterns with photolithography and light-cured inkjet printing methods
  27. Multifunctional nanoparticles for targeted delivery of apoptin plasmid in cancer treatment
  28. Thermal stability, mechanical, and optical properties of novel RTV silicone rubbers using octa(dimethylethoxysiloxy)-POSS as a cross-linker
  29. Preparation and applications of hydrophilic quaternary ammonium salt type polymeric antistatic agents
  30. Coefficient of thermal expansion and mechanical properties of modified fiber-reinforced boron phenolic composites
  31. Synergistic effects of PEG middle-blocks and talcum on crystallizability and thermomechanical properties of flexible PLLA-b-PEG-b-PLLA bioplastic
  32. A poly(amidoxime)-modified MOF macroporous membrane for high-efficient uranium extraction from seawater
  33. Simultaneously enhance the fire safety and mechanical properties of PLA by incorporating a cyclophosphazene-based flame retardant
  34. Fabrication of two multifunctional phosphorus–nitrogen flame retardants toward improving the fire safety of epoxy resin
  35. The role of natural rubber endogenous proteins in promoting the formation of vulcanization networks
  36. The impact of viscoelastic nanofluids on the oil droplet remobilization in porous media: An experimental approach
  37. A wood-mimetic porous MXene/gelatin hydrogel for electric field/sunlight bi-enhanced uranium adsorption
  38. Fabrication of functional polyester fibers by sputter deposition with stainless steel
  39. Facile synthesis of core–shell structured magnetic Fe3O4@SiO2@Au molecularly imprinted polymers for high effective extraction and determination of 4-methylmethcathinone in human urine samples
  40. Interfacial structure and properties of isotactic polybutene-1/polyethylene blends
  41. Toward long-live ceramic on ceramic hip joints: In vitro investigation of squeaking of coated hip joint with layer-by-layer reinforced PVA coatings
  42. Effect of post-compaction heating on characteristics of microcrystalline cellulose compacts
  43. Polyurethane-based retanning agents with antimicrobial properties
  44. Preparation of polyamide 12 powder for additive manufacturing applications via thermally induced phase separation
  45. Polyvinyl alcohol/gum Arabic hydrogel preparation and cytotoxicity for wound healing improvement
  46. Synthesis and properties of PI composite films using carbon quantum dots as fillers
  47. Effect of phenyltrimethoxysilane coupling agent (A153) on simultaneously improving mechanical, electrical, and processing properties of ultra-high-filled polypropylene composites
  48. High-temperature behavior of silicone rubber composite with boron oxide/calcium silicate
  49. Lipid nanodiscs of poly(styrene-alt-maleic acid) to enhance plant antioxidant extraction
  50. Study on composting and seawater degradation properties of diethylene glycol-modified poly(butylene succinate) copolyesters
  51. A ternary hybrid nucleating agent for isotropic polypropylene: Preparation, characterization, and application
  52. Facile synthesis of a triazine-based porous organic polymer containing thiophene units for effective loading and releasing of temozolomide
  53. Preparation and performance of retention and drainage aid made of cationic spherical polyelectrolyte brushes
  54. Preparation and properties of nano-TiO2-modified photosensitive materials for 3D printing
  55. Mechanical properties and thermal analysis of graphene nanoplatelets reinforced polyimine composites
  56. Preparation and in vitro biocompatibility of PBAT and chitosan composites for novel biodegradable cardiac occluders
  57. Fabrication of biodegradable nanofibers via melt extrusion of immiscible blends
  58. Epoxy/melamine polyphosphate modified silicon carbide composites: Thermal conductivity and flame retardancy analyses
  59. Effect of dispersibility of graphene nanoplatelets on the properties of natural rubber latex composites using sodium dodecyl sulfate
  60. Preparation of PEEK-NH2/graphene network structured nanocomposites with high electrical conductivity
  61. Preparation and evaluation of high-performance modified alkyd resins based on 1,3,5-tris-(2-hydroxyethyl)cyanuric acid and study of their anticorrosive properties for surface coating applications
  62. A novel defect generation model based on two-stage GAN
  63. Thermally conductive h-BN/EHTPB/epoxy composites with enhanced toughness for on-board traction transformers
  64. Conformations and dynamic behaviors of confined wormlike chains in a pressure-driven flow
  65. Mechanical properties of epoxy resin toughened with cornstarch
  66. Optoelectronic investigation and spectroscopic characteristics of polyamide-66 polymer
  67. Novel bridged polysilsesquioxane aerogels with great mechanical properties and hydrophobicity
  68. Zeolitic imidazolate frameworks dispersed in waterborne epoxy resin to improve the anticorrosion performance of the coatings
  69. Fabrication of silver ions aramid fibers and polyethylene composites with excellent antibacterial and mechanical properties
  70. Thermal stability and optical properties of radiation-induced grafting of methyl methacrylate onto low-density polyethylene in a solvent system containing pyridine
  71. Preparation and permeation recognition mechanism of Cr(vi) ion-imprinted composite membranes
  72. Oxidized hyaluronic acid/adipic acid dihydrazide hydrogel as cell microcarriers for tissue regeneration applications
  73. Study of the phase-transition behavior of (AB)3 type star polystyrene-block-poly(n-butylacrylate) copolymers by the combination of rheology and SAXS
  74. A new insight into the reaction mechanism in preparation of poly(phenylene sulfide)
  75. Modified kaolin hydrogel for Cu2+ adsorption
  76. Thyme/garlic essential oils loaded chitosan–alginate nanocomposite: Characterization and antibacterial activities
  77. Thermal and mechanical properties of poly(lactic acid)/poly(butylene adipate-co-terephthalate)/calcium carbonate composite with single continuous morphology
  78. Review Articles
  79. The use of chitosan as a skin-regeneration agent in burns injuries: A review
  80. State of the art of geopolymers: A review
  81. Mechanical, thermal, and tribological characterization of bio-polymeric composites: A comprehensive review
  82. The influence of ionic liquid pretreatment on the physicomechanical properties of polymer biocomposites: A mini-review
  83. Influence of filler material on properties of fiber-reinforced polymer composites: A review
  84. Rapid Communications
  85. Pressure-induced flow processing behind the superior mechanical properties and heat-resistance performance of poly(butylene succinate)
  86. RAFT polymerization-induced self-assembly of semifluorinated liquid-crystalline block copolymers
  87. RAFT polymerization-induced self-assembly of poly(ionic liquids) in ethanol
  88. Topical Issue: Recent advances in smart polymers and their composites: Fundamentals and applications (Guest Editors: Shaohua Jiang and Chunxin Ma)
  89. Fabrication of PANI-modified PVDF nanofibrous yarn for pH sensor
  90. Shape memory polymer/graphene nanocomposites: State-of-the-art
  91. Recent advances in dynamic covalent bond-based shape memory polymers
  92. Construction of esterase-responsive hyperbranched polyprodrug micelles and their antitumor activity in vitro
  93. Regenerable bacterial killing–releasing ultrathin smart hydrogel surfaces modified with zwitterionic polymer brushes
Sign up now to receive a 20% welcome discount
Institutional Access
How does access work?
Have an idea on how to improve our website?
Please write us.
© 2025 De Gruyter Brill
Downloaded on 17.9.2025 from https://www.degruyterbrill.com/document/doi/10.1515/epoly-2022-0049/html
Scroll to top button