A Kinetic Approach On Thermal Properties of Vinyl Ester Resin Synthesized by Different Molecular Weight Epoxy Resin with Phenyl Glycidal Ether

Abstract

The esterification of bisphenol-A based epoxy resin having different molecular weight epoxies in presence of phenyl glycidyl ether and acrylic acid was carried out at 85°C using triphenyl phosphine as a catalyst. The structural changes were studied by FTIR. The thermal properties of the prepared vinyl ester resin (VER) samples were studied by (DSC) and (TG) analysis. The cure temperature increased with the increase of molecular weight of the parent epoxy resin. It was also found that the degradation of all the samples proceeded with two-step degradation mechanism. In the first step, it preceded with second order whereas in the second step the order of reaction increased with increasing molecular weight of parent epoxy. The energy of activation, E, was found to be maximum in the case of VER synthesized with low molecular weight epoxy, the value of pre-exponential factor (Z) and rate decomposition constant, k, for decomposition of the samples was found to be similar trend as activation energy.