Verônica Távilla Ferreira Silva, Adriane Maria Ferreira Milagres^*

Journal of Renewable Materials, Vol.12, No.3, pp. 539-551, 2024, DOI:10.32604/jrm.2023.045726

Abstract This study was conducted to evaluate the effectiveness of enzymes in purifying and reducing the degree of polymerization of cellulose for the production of dissolving pulp. Our goal was to determine the contributions of xylanase (X) and endoglucanase (EG) in the treatment of pulp, specifically by quantifying the formation of soluble and insoluble reducing sugars using the dinitrosalycilic acid (DNS) test. Predominantly, the release of soluble reducing sugars (RSSol) was enhanced after xylanase treatment, while endoglucanase (EG) treatment led to changes in insoluble reducing sugars (RSIns). The maximum synergism was observed for RSIns when a high ratio of endoglucanase to… More > Graphic Abstract

Liting Jia¹, Xiao Han¹, Cuixia Qiao², Gang Zhao², Yanzhi Xia¹, Zhixin Xue^1,*

Journal of Renewable Materials, Vol.12, No.3, pp. 427-441, 2024, DOI:10.32604/jrm.2023.044310

Abstract Ba²⁺ pre-crosslinked carrageenan fiber (Ba/CAF) was prepared by adding a small amount of Ba²⁺ to the carrageenan (CA) solution as the spinning solution. Ba/CAF-n/A, Ba/CAF-n/B and Ba/CAF-n/C were prepared with ethanol solution (combine A), high concentration BaCl₂ solution (combine B) and low concentration BaCl₂ solution (combine C), as coagulation bath and stretch bath, respectively. The combination of coagulation bath and stretch bath suitable for Ba²⁺ pre-crosslinking wet spinning was screened. The results showed that Ba²⁺ can induce the birefringence of the CA molecular chain, and the Ba²⁺ pre-crosslinking effect is the best when the CA mass fraction is 8.0 wt%.… More > Graphic Abstract

KAVITA^*, R.K. TIWARI

Journal of Polymer Materials, Vol.36, No.2, pp. 195-205, 2019, DOI:10.32381/JPM.2019.36.02.7

Abstract The effect of poly (vinyl butyral) and acid functionalized multiwalled carbon nanotubes (f-MWCNT) on the thermal and mechanical performance of Kevlar fiber reinforced novolac epoxy nanocomposites was investigated and presented in this paper. Nanocomposite containing 1.5 wt. % poly (vinyl butyral) and 0.5 wt. % f-MWCNT exhibited best thermal and mechanical properties (except flexural strength) among all the nanocomposites reported here. It showed ~5%, 27% and 126 % improvement in tensile strength, young’s modulus and impact strength respectively as compared to the neat novolac epoxy Kevlar composite.Nanocomposite containing 0.5 wt. % f- MWCNT and 2 wt. % poly (vinyl butyral)… More >

JITENDRA. S. TATE^1,2,*, HARISH KALLAGUNTA^1,2, ANDREW ALVAREZ¹

Journal of Polymer Materials, Vol.38, No.1-2, pp. 101-120, 2021, DOI:10.32381/JPM.2021.38.1-2.9

Abstract The exponential growth in composites and their increased use in military, aerospace, energy, and automotive industry is driven by their high performance and light weight. High performance thermosetting polymers such as cyanate ester have received considerable attention due to its ability of volatile-free curing. It also offers advantages such as excellent radiation shielding, high thermal stability, and hydrophobicity with lots of potential for enhanced mechanical strength. This research article discusses the results of effects of multiwalled carbon nanotubes (MWCNT) at predetermined loading levels of 0.5wt%, 1wt% and 1.5wt% on mechanical, thermal and flammability properties of cyanate ester modified carbon fiber… More >

RITESH D. BHATT, JIGNESH P. PATEL, P. H. PARSANIA^*

Journal of Polymer Materials, Vol.38, No.1-2, pp. 71-87, 2021, DOI:10.32381/JPM.2021.38.1-2.7

Abstract Glass/Biofibers/Epoxy methacrylate of bisphenol-C (G/BF/EBCMAS) sandwich composites was prepared by compression molding. G/BF/EBCMAS showed good mechanical and good to excellent electrical properties and excellent chemical resistance. Studied properties are compared with EBCMAS and G/EBCMAS. In comparison with G/EBCMAS, G/BF/EBCMAS showed considerable decline of tensile strength (18-63.4%), flexural strength (18.8-38.7%), flexural modulus (12.8-50.7%), Izod impact strength (17.4-43.5%), Barcol hardness (2.1-16.7%) and dielectric strength (23.8-76.8%) except flexural strength of G/BM/EBCMAS. G/WC/EBCMAS (96.7%), G/B/EBCMAS (79.2%), G/GN/EBCMAS (83.3%) and G/RH/EBCMAS (97.9%) showed decline of volume resistivity, whereas other sandwich composites showed 1150-58233% improvement. The decrease in mechanical properties and dielectric strength of G/BF/EBCMAS sandwich… More >

GAURAV AGARWAL

Journal of Polymer Materials, Vol.39, No.3-4, pp. 255-267, 2022, DOI:10.32381/JPM.2022.39.3-4.6

Abstract Studies were conducted to observe the effect of fracture toughness and damping response on fabric reinforced epoxy polymer composites. The samples of glass fabric, kevlar fabric and carbon fabric having 15wt%, 25wt%, 35wt%, 45wt% and 55wt % fabric content were prepared and tested following ASTM standards. Fracture toughness, peak load and increase in energy absorption are determined for the fabric-epoxy composites. Effect of temperature on storage modulus, loss modulus and tan delta values for various percentages of fabric epoxy composites are noticed and corresponding damping response behaviour is determined. The results revealed that reduction in strength at higher percentage of… More >

MUHAMAD SOFFI BIN MANDA^1,2, MOHD RUZAIMI BIN MAT REJAB¹, SHUKUR ABU HASSAN^3,4, MAT UZIR BIN WAHIT^3,4, JOSEPH SELVI BINOJ^5,*, BRIGHT BRAILSON MANSINGH⁶, SITI SAFARAH BINTI AMIRNUDDIN³, ALAMRY ALI⁷, KHENG LIM GOH^8,9, DIDIK NURHADIYANTO¹⁰

Journal of Polymer Materials, Vol.39, No.3-4, pp. 241-253, 2022, DOI:10.32381/JPM.2022.39.3-4.5

Abstract This study investigates the potential of Tin Slag Polymer Concrete (TSPC) strengthening through confinement using basalt fiber reinforced polymer (BFRP) and aramid fiber reinforced polymer (AFRP) confinement. TSPC short cylindrical column samples have been wrapped with BFRP and AFRP in a single layer (30 mm overlap) using Sikadur-330 epoxy and final samples were coded as TSPC-UC, TSPC-BF and TSPC-AF for unconfined, BFRP and AFRP for confined respectively. After curing for 30 days at room temperature, compressive test has been performed to know the strength, modulus, strain, fracture energy and failure modes of unconfined and confined TSPC. Test result shows that… More >

RITESH D. BHATT, JIGNESH P. PATEL, PARSOTAM H. PARSANIA^*

Journal of Polymer Materials, Vol.39, No.3-4, pp. 223-239, 2022, DOI:10.32381/JPM.2022.39.3-4.4

Abstract Compression-molded epoxy methacrylate of bisphenol-C-jute/treated jute-banana/groundnut/ cane sugar/pineapple leaf/rice husk/wheat husk sandwich composites were fabricated under 5 MPa pressure at room temperature for 3 h. Alkali treated jute-natural fiber sandwich composites displayed considerably improved mechanical properties over untreated jute-natural fiber sandwich composites due to surface modification of the jute fibers. Both types of sandwich composites showed high water uptake tendency, excellent hydrolytic stability against acids, alkali, and salt solutions, and also a longer equilibrium time at 30o C. Alkali treated sandwich composites revealed a considerably lower water uptake tendency than untreated sandwich composites. Observed water uptake trend is H₂ SO₄… More >

RITESH D. BHATT, JIGNESH P. PATEL, PARSOTAM H. PARSANIA^*

Journal of Polymer Materials, Vol.39, No.3-4, pp. 205-221, 2022, DOI:10.32381/JPM.2022.39.3-4.3

Abstract Epoxy methacrylate of bisphenol-C-jute/treated jute and their sandwich composites of white coir, brown coir, wild almond, bamboo, betel nut, and palmyra were prepared by a compression molding technique under 5MPa pressure and at room temperature for three h. The neat sample showed almost double tensile strength than its jute composite, while it is comparable for treated jute. The composites revealed substantially improved flexural strength compared to neat. The neat, jute/treated jute and their sandwich composites indicated good impact strength, pretty good Barcol hardness, and fairly good electric strength. The neat sample showed excellent volume resistivity, while jute/treated jute and their… More >

PARSOTAM H. PARSANIA^1,*, JIGNESH V. PATEL², JIGNESH P. PATEL³

Journal of Polymer Materials, Vol.40, No.3-4, pp. 271-284, 2023, DOI:10.32381/JPM.2023.40.3-4.9

Abstract Bisphenol-C epoxy crotonate resin was synthesized by reacting 8.09g epoxy resin of bisphenolC, and 2.15g crotonic acid using 25 mL 1,4-dioxane as a solvent, and 1 mL triethylamine as a catalyst at reflux temperature for 1-6 h. Solid epoxy crotonate (ECCR) is highly soluble in common organic solvents. ECCR was characterized by its acid (24.5-1.5 mg KOH/g) and hydroxyl (504.5-678.4 mg KOH/g) values. The structure of ECCR is supported by FTIR and 1 HNMR spectroscopic methods. A DSC endothermic transition at 229o C indicated melting followed by thermal polymerization of ECCR. ECCR is thermally stable up to 320o C and… More >