JALPA V. CHOPDA, DHARMESH B. SANKHAVARA, JIGNESH P. PATEL, P. H. PARSANIA^*

Journal of Polymer Materials, Vol.36, No.4, pp. 391-399, 2019, DOI:10.32381/JPM.2019.36.04.8

Abstract The epoxymethcrylate resin (EMBHBCMA) of (2E, 6E)-bis(4-hydroxybenzylidene)-4- methylcyclohexanone(EMBHBC) was synthesized by condensing EMBHBC and methacrylic acid (1:2 mole ratio) by using 1,4-dioxane as a solvent and triethylamine as a catalyst at reflux temperature for 1-5 h to get acid value < 10. The structure of EMBHBCMA was supported by UV-Vis, FTIR, ¹ HNMR and ¹³CNMR spectroscopic techniques. Molecular weights and molecular weight distribution of EMBHBCMA were determined by gel permeation chromatography. EMBHBCMA is thermally stable up to about 300°C and followed two step degradation reactions. Kinetic parameters such as n, Ea, A and ΔS* were determined according to Anderson-Freeman method… More >

DHARMESH B. SANKHAVARA, JALPA V. CHOPDA, JIGNESH P. PATEL, PARSOTAM H. PARSANIA^*

Journal of Polymer Materials, Vol.36, No.4, pp. 371-379, 2019, DOI:10.32381/JPM.2019.36.04.6

Abstract The epoxy methacrylate of (2E,6E)-2, 6-bis(4-hydroxybenzylidene)cyclohexanone (EBHBCMA) was synthesized by condensing 0.02 equi. EBHBC, 0.04 equi. methacrylic acid, 50 mL THF as a solvent and 0.2 mL triethylamine as a catalyst at reflux temperature for 1-5 h to get acid value < 10. EBHBCMA showed good solubility in common solvents. The structure of EBHBCMA was supported by UV-Vis., FTIR, 1 H NMR, and 13C NMR spectroscopic techniques. DSC thermogram of EBHBCMA exhibited two endothermic peaks (86.4 and 117.1 °C) and one exothermic peak (142.6°C) due to moisture release, melting and curing of the resin, respectively. EBHBCMA is thermally stable up… More >

JALPA V. CHOPDA, DHARMESH B. SANKHAVARA, JIGNESH P. PATEL, P. H. PARSANIA^*

Journal of Polymer Materials, Vol.36, No.1, pp. 101-109, 2019, DOI:10.32381/JPM.2019.36.01.8

Abstract The epoxy resin (EMBHBC) of (2E,6E)-bis (4-hydroxybenzylidene)-4-methyl cyclohexanone (MBHBC) was synthesized by condensing 0.5 mol MBHBC and 2.5 mol epichlorohydrin in 500 mL isopropyl alcohol as a solvent and 1.0 mol NaOH in 50 mL water as a catalyst at 80°C for 3 h. The structure of EMBHBC was supported by UV-Vis, FTIR, ¹ HNMR and ¹³CNMR spectroscopic techniques. Molecular weights and molecular weight distribution of EMBHBC were determined by gel permeation chromatography. DSC thermogram of EMBHC showed one endothermic transition (95.9°C) and two exothermic transitions (317.7°C and 382.2°C) due to melting and decomposition transitions, respectively. EMBHBC is thermally stable… More >

CHUNYAN LIU^*, YUNHE LIU, ZIHAN PAN, QIUTING LI, HAN XU, TAO LIU

Journal of Polymer Materials, Vol.36, No.1, pp. 87-99, 2019, DOI:10.32381/JPM.2019.36.01.7

Abstract In this work, a series of novel lignin-based bis-benzoxazine monomers were efficiently synthesized by the reaction of renewable phenols: guaiacol, vanillyl alcohol, eugenol, vanillin with ethylene diamine and paraformaldehyde. The chemical structures of these lignin-based bis-benzoxazine monomers were confirmed by ¹H-NMR, ¹³C-NMR and FTIR, indicating the formation of benzoxazine ring. The obtained bis-benzoxazine monomers were cured via thermal treatment. The curing behavior of these lignin-based bis-benzoxazine monomers were compared and analyzed via differential scanning calorimetry (DSC), showing that Va-e possessed higher ring-opening polymerization activity than G-e, while E-e and V-e had lower curing activity than G-e. More >

DHARMESH B. SANKHAVARA, JALPA CHOPDA, JIGNESH P. PATEL, P. H. PARSANIA^*

Journal of Polymer Materials, Vol.36, No.1, pp. 13-21, 2019, DOI:10.32381/JPM.2019.36.01.2

Abstract Chalcone based epoxy resin (EBHBC) of (2E, 6E)- bis(4-hydroxybenzylidene) cyclohexanone (BHBC) was synthesized by condensing 0.5 mol BHBC and 2.5 mol epichlorohydrin in 500 mL isopropanol as a solvent and 1.0 mol NaOH in 50 mL water as a catalyst at 80o C. The structure of EBHBC is supported by spectral techniques. Molecular weights and molecular weight distribution of EBHBC were determined by gel permeation chromatography. DSC thermogram of EBHC showed one endothermic transition (146.1°C) and two endothermic transitions (253.52°C and 397.34°C) due to melting, some physical change and decomposition transitions, respectively. EBHBC is thermally stable up to about 300o… More >

JALPA V. CHOPDA, DHARMESH B. SANKHAVARA, JIGNESH P. PATEL, P. H. PARSANIA^*

Journal of Polymer Materials, Vol.38, No.1-2, pp. 35-48, 2021, DOI:10.32381/JPM.2021.38.1-2.4

Abstract Conventional curing study of epoxy resin of (2E, 6E)-bis (4-hydroxybenzylidene)-4-methyl cyclohexanone (EMBHBC) was conducted at 140 0 /150 0 C by using 4,4’-diaminodiphenylmethane (DDM),4,4’-diaminodiphenylsulphone (DDS),4-4’-diaminodiphenyl ether (DDE), p-phenylenediamine (PDA), 1,2,3,6-tetrahydrophthalic anhydride(THPA), maleic anhydride (MAH) and pyromellitic dianhydride (PMDA). The gel time for DDS, THPA and DDM hardeners are found considerably longer than those of DDE, PDA, MAH and PMDA systems indicated different reactivity towards curing of EMBHBC. Sol–gel analysis of cured resins was carried out in DMF at room temperature. Diamines cured samples showed 76.3-97.5% gel fractions, while anhydrides cured samples showed 84.6-99.6% gel fractions. DDM, PDA and THPA are… More >

Zhenguo Wang, Lenan Wang, Yejing Meng^*, Yong Wen, Jianzhong Pei

Journal of Renewable Materials, Vol.11, No.5, pp. 2469-2489, 2023, DOI:10.32604/jrm.2023.025497

Abstract In the field of roads, due to the effect of vehicle loads, piezoelectric materials under the road surface can convert mechanical vibration into electrical energy, which can be further used in road facilities such as traffic signals and street lamps. The barium titanate/polyvinylidene fluoride (BaTiO₃/PVDF) composite, the most common hybrid ceramic-polymer system, was widely used in various fields because the composite combines the good dielectric property of ceramic materials with the good flexibility of PVDF material. Previous studies have found that conductive particles can further improve the dielectric and piezoelectric properties of other composites. However, few studies have investigated the… More >

Yodthong Baimark^*, Theeraphol Phromsopha

Journal of Renewable Materials, Vol.11, No.4, pp. 1881-1894, 2023, DOI:10.32604/jrm.2023.025400

Abstract A poly(L-lactide)-b-poly(ethylene glycol)-b-poly(L-lactide)(PLLA-PEG-PLLA) block copolymer has great potential for use as a flexible bioplastic. Highly flexible bioplastics are required for flexible packaging applications. In this work, a PEG was incorporated into block copolymer as a plasticizer by solvent casting. PLLA-PEG-PLLA/ PEG blends with different blend ratios were prepared, and the plasticizing effect and miscibility of PEG in block copolymer were intensively investigated compared to PLLA/PEG blends. The results indicated that the PEG was an effective plasticizer for the block copolymer. The blending of PEG decreased glass-transition temperature and accelerated the crystallization of both the PLLA and PLLA-PEG-PLLA matrices. The PEG… More > Graphic Abstract

Shuangsheng Zhang, Bin Sun, Siyu Li, Xiangyu Lin, Muhua Chen^*, Xu Xu^*

Journal of Renewable Materials, Vol.11, No.2, pp. 853-865, 2023, DOI:10.32604/jrm.2022.022901

Abstract Hydrogels have been widely applied in agricultural drought-resistance, pollution regulation, drug delivery and so on. Acrylamide (AM) is usually used as raw material to synthesize acrylamide hydrogels. However, inherently low mechanical strength greatly limits their applications in some special areas. Therefore, it is necessary to choose suitable functional monomers to optimize acrylamide hydrogels and improve their mechanical performances. In this paper, a novel acrylamide monomer modified by rosin was synthesized, and then polyacrylamide/rosin-based acrylamide (RAM) composite hydrogels were prepared via free radical polymerization using potassium persulfate as initiator, N, N′-methylene-bisacrylamide (MBA) as a crosslinker. The influence of RAM monomer was… More > Graphic Abstract

Weeradech Kiratitanavit¹, Sethumadhavan Ravichandran²,Zhiyu Xia¹, Jayant Kumar^3,4, Ramaswamy Nagarajan^1,4,*

Journal of Renewable Materials, Vol.1, No.4, pp. 289-301, 2013, DOI:10.7569/JRM.2013.634126

Abstract Globally, certain types of halogenated fl ame retardant additives (FR) are becoming increasingly regulated or banned from being used in polymers. There is an immediate need for alternative non-toxic thermally stable polymers and char-forming additives. Development of non-halogenated FR for the commonly used and highly fl ammable thermoplastics, namely polyolefi ns, is particularly important and challenging. This research explores the possibility of utilizing char-forming compounds based on polymer of cardanol as an additive that can lower the heat release capacity (HRC) when blended with polypropylene (PP). Polycardanol is thermally stable and exhibits moderate HRC upon thermal decomposition and forms a… More >