JIANGBO WANG^*

Journal of Polymer Materials, Vol.36, No.4, pp. 381-389, 2019, DOI:10.32381/JPM.2019.36.04.7

Abstract In this study, a novel flame retardant polyvinylphenylsilsesquioxane (PVP) was added into epoxy resin (EP) to prepare EP/PVP (FREP) composites. The results of cone calorimeter measurement showed that in comparison with virgin EP, the peak heat release rate (PHRR) and total heat release (THR) of FREP were reduced by 27.3% and 10.4%, respectively. Moreover, the thermal degradation behavior of FREP was studied by the Kissinger and Ozawa-Flynn-Wall methods. The results suggested that the addition of PVP greatly enhanced the thermal stability of EP in the final stage, which could be attributed to that the branched silicone with vinyl and phenyl… 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 >

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 >

ANIL KUMAR VEERAPANENI¹, CHANDRASEKAR KUPPAN^2,*, MURTHY CHAVALI^3,*

Journal of Polymer Materials, Vol.37, No.3-4, pp. 121-130, 2020, DOI:10.32381/JPM.2020.37.3-4.1

Abstract The mechanical properties of hybrid nanocomposites made of epoxy/glass fibre dispersed with nano-α-Al₂ O₃ powder at different weight percentages were studied.The effect of nano-α- Al₂O₃ size and wt% on mechanical properties like tensile, flexural, interlaminar shear stress and hardness enhanced because of their higher surface area and interfacial polymer-metal interaction. The nanoparticle embedded laminates have shown improvement in flexural strength,and hardness when compared to laminate without nano-α-Al₂ O₃. The properties varied with the loading and size of the nanoparticles. The tensile strength was highest for 0.5 wt% of 200nm nano-α-Al₂O₃, which is 167.80 N/m₂.The highest flexural strength was observed for… 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 >

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

Journal of Polymer Materials, Vol.38, No.1-2, pp. 11-19, 2021, DOI:10.32381/JPM.2021.38.1-2.2

Abstract The curing of epoxy resin of (2E, 6E)-2,6-bis(4-hydroxy benzylidene) cyclohexanone (EBHBC) was carried out at four different heating rates in the nitrogen atmosphere by using 4,4’-diamino diphenylmethane (DDM), 4,4’-diamino diphenyl sulfone (DDS), and 1,2,3,6-tetrahydrophthalic anhydride (THPA) as hardeners. From DSC curves onset, peak exotherm and end set temperatures, as well as heat release, were derived. The energy of activation was derived following Kissinger and Ozawa methods. Observed trend in Ea is EBHBC-THPA > EBHBCDDS > EBHBC-DDM > EBHBC. Nature and chemical structure of the hardeners affected the curing of EBHBC. More >

R. J. Johnson^∗, R. Pitchumani^†

Frontiers in Heat and Mass Transfer, Vol.1, No.1, pp. 1-9, 2010, DOI:10.5098/hmt.v1.1.3007

Abstract Much research is currently being performed with carbon nanotube additives to neat resin systems to enhance properties such as thermal and electrical conductivity, strength, modulus and damping. Fabrication of parts based on carbon nanotube filled resin systems requires information on their cure kinetics and rheology, which has been relatively less studied so far. This work presents an extensive experimental study that systematically characterizes the cure kinetics and viscosity as a function of degree of cure and temperature of EPON 815C/EPICURE 3274 epoxy resin system laden with carbon nanotubes. Studies are conducted to determine the effects of the carbon nanotube loading… More >

Chunhua Liu¹, Dongfang Zou¹, Qinqin Huang¹, Shang Li², Xia Zheng¹, Xingong Li^1,*

Journal of Renewable Materials, Vol.11, No.10, pp. 3613-3624, 2023, DOI:10.32604/jrm.2023.028111

Abstract The residual resources of ramie fiber-based textile products were used as raw materials. Ramie fiber felt (RF) was modified by NaClO₂ aqueous solution and then impregnated with water-based epoxy resin (WER). RF/WER transparent composite materials were prepared by lamination hot pressing process. The composite materials’color difference, transmittance, haze, density, water absorption, and mechanical properties were determined to assess the effects of NaClO₂ treatment and the number of ramie fiber layers on the properties of the prepared composites. The results showed significantly improved optical and mechanical properties of the RF/WER transparent composites after NaClO₂ treatment. With the increase of ramie fiber… More > Graphic Abstract

Jinlong Shang^*

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.9, pp. 2315-2328, 2023, DOI:10.32604/fdmp.2023.026742

Abstract In this study, the durability of a new polymer carbon fiber-reinforced epoxy resin used to produce composite material in the aerospace field is investigated through analysis of the corrosion phenomena occurring at the microscopic scale, and the related infrared spectra and thermal properties. It is found that light and heat can contribute to the aging process. In particular, the longitudinal tensile strength displays a non-monotonic trend, i.e., it first increases and then decreases over time. By contrast, the longitudinal compressive and inter-laminar shear strengths do not show significant changes. It is also shown that the inter-laminar shear strength of carbon… More >

Nurul Anis Athirah Ab Aziz^*, Chin Wei Lai^*, Boon Hoong Ong

Journal of Renewable Materials, Vol.11, No.6, pp. 2745-2770, 2023, DOI:10.32604/jrm.2023.025899

Abstract Nowadays, corrosion is not only undesirable, but it also has a significant influence on the industrial sectors and technical innovations that have demand for metals. The global economic damage is expected to reach $2.5 trillion, equivalent to more than 3.4% of the world’s GDP in 2013. It is linked with significant financial harm, manufacturing pollution, and safety issues. An electrochemical process primarily induces metal corrosion at the metalelectrolyte interface region, caused by steel oxidation and the reduction of oxygen, protons, and water. Therefore, organic and epoxy coatings can be applied as protective coatings. Additionally, it can prevent metal corrosion in… More > Graphic Abstract