A. MADHAN KUMAR¹, K. JAYAKUMAR^2,*, M. SHALINI³

Journal of Polymer Materials, Vol.39, No.3-4, pp. 269-281, 2022, DOI:10.32381/JPM.2022.39.3-4.7

Abstract Polylactic acid (PLA) is the most popular thermoplastic biopolymer providing a stiffness and strength alternative to fossil-based plastics. It is also the most promising biodegradable polymer on the market right now, thus gaining a substitute for conservative artificial polymers. Therefore, the current research focuses on synthesizing and mechanical characterization of particlereinforced PLA composites. The hot compression molding technique was used to fabricate PLA-based composites with 0, 2.5, 5, and 7.5 weight % of sawdust, rice husk, and bagasse particle reinforcements to enhance the performance of the PLA. The pellets of PLA matrix were taken with an average size of 3… 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 >

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 >

K. KRISHNAMOORTHY^a,*, N. PRABHU^b

Journal of Polymer Materials, Vol.40, No.3-4, pp. 215-226, 2023, DOI:10.32381/JPM.2023.40.3-4.7

Abstract The acoustic emission monitoring with artificial neural networks predicts the ultimate strength of glass/epoxy composite laminates using Acoustic Emission Data. The ultimate loads of all the specimens were used to characterise the emission of hits during failure modes. The six layered glass fiber laminates were prepared (in woven mat form) with epoxy as the binding medium by hand lay-up technique. At room temperature, with a pressure of 30 kg/cm², the laminates were cured. The laminates of standard dimensions as per ASTM D3039 for the tensile test were cut from the lamina. The Acoustic Emission (AE) test was conducted on these… More >

ARUN KUMAR M, JAYAKUMARI LS^*, RAMJI CHANDRAN

Journal of Polymer Materials, Vol.40, No.3-4, pp. 141-156, 2023, DOI:10.32381/JPM.2023.40.3-4.2

Abstract Nanocomposites are very important materials because it imparts superior properties than other composites with low level of filler loading. Styrene butadiene rubber (SBR) is a non-polar rubber which acts as an insulator and has low electrical conductivity. Graphene platelet nano-powder from 0.1 to 1.25 phr level is incorporated into SBR rubber in order to improve the electrical properties. Comparative studies on electrical and mechanical properties of styrene butadiene rubber with graphene platelet nano-powder (GPN) by varying the filler content are made. The incorporation of Graphene platelet nano-powder increases the electrical conductivity in styrene butadiene rubber. It has been observed that… More >

Dejin Mu^1,2, Lin Chen^1,2, Heze Wang^1,2, Zhaoliu Hu^1,2, Sihui Chen^1,2, Shi Chen^1,2, Nianhui Cai^1,2, Yulan Xu^1,2, Junrong Tang^1,2,*

Phyton-International Journal of Experimental Botany, Vol.93, No.3, pp. 503-516, 2024, DOI:10.32604/phyton.2024.048786

Abstract Phenylalanine ammonia lyase (PAL) is the rate-limiting and pivotal enzyme of the general phenylpropanoid pathway, but few reports have been found on PAL genes in Pinus yunnanensis. In the present study, three PAL genes were cloned and identified from P. yunnanensis seedlings for the first time, namely, PyPAL-1, PyPAL-2, and PyPAL-3. Our results indicated that the open-reading frames of PyPAL genes were 2184, 2157, and 2385 bp. Phylogenetic tree analysis revealed that PyPALs have high homology with other known PAL genes in other plants. In vitro enzymatic analysis showed that all three PyPAL recombinant proteins could catalyze the deamination of… More >

Fenglan Zhao¹, Jizhi Jin¹, Meng Yang¹, Franklin Eduardo Melo Santiago², Jianping Xue¹, Li Xu^3,*, Yongbo Duan^1,*

Phyton-International Journal of Experimental Botany, Vol.93, No.3, pp. 611-625, 2024, DOI:10.32604/phyton.2024.048295

Abstract

Seed germination with selenium (Se) is promising for producing Se-biofortified foods. Mungbean (Vigna radiata (L.) Wilczek) sprout is freshly eaten as a salad dressed with sauce, making it superior for Se biofortification. Since the Se safety range for the human body is extremely narrow, it is imperative to evaluate the genotypic responses of mungbean sprouts to Se. This study evaluated the Se enrichment capacity and interaction with flavonoids and antioxidant systems in sprouts of 20 mungbean germplasms. Selenium treatment was done by immersing mungbean seeds in 20 μM sodium selenite solution for 8 h. Afterward, the biomass, Se amounts, flavonoid… More >

Xiaojie Liang^1,2, Wei An², Yuekun Li², Yajun Wang², Xiaoya Qin², Yanhong Cui¹, Shuchai Su^1,*

Phyton-International Journal of Experimental Botany, Vol.93, No.3, pp. 467-486, 2024, DOI:10.32604/phyton.2024.047628

Abstract

Goji berry (Lycium barbarum L.) is substantially dependent on nitrogen fertilizer application, which can significantly enhance fruit yield and Goji berry industrial development in Ningxia, China. This study aimed to analyze the functions of differential nitrogen application rates including low (N1), medium (N2), and high (N3) levels in soil microbial community structure (bacterial and fungal) at 2 diverse soil depths (0–20, 20–40 cm) through high-throughput sequencing technology by targeting 16S RNA gene and ITS1 & ITS2 regions. All the observed physicochemical parameters exhibited significant improvement (p < 0.05) with increased levels of nitrogen and the highest values for most parameters… More >