Kinetic study of the effect of catalysts on the curing of biphenyl epoxy resin

摘要

The investigation of cure kinetics of biphenyl epoxy (4,4'-diglycidyloxy-3,3',5,5'-tetramethyl biphenyl)dicyclopentadiene type phenolic resin system with different kinds of catalysts was performed by a differential scanning calorimeter using an isothermal approach. All kinetic parameters of the curing reaction including the reaction order, activation energy, and rate constant were calculated and reported. The results indicate that the curing reaction of the formulations using triphenylphosphine (TPP), 1-benzyl-2-methylimidazole (1B2MI), and tris(4-methoxyphenyl)phosphine (TPAP) as a catalyst proceeds through an nth-order kinetic mechanism, whereas that of the formulations using diazabicycloundecene (DBU) and tetraphenyl phosphonium tetraphenyl berate (TPP-TPB) proceeds by an autocatalytic kinetic mechanism. To describe the cure reaction in the latter stage, we have used semiempirical relationship proposed by Chern and Poehlein. By combining an nth-order kinetic model or an autocatalytic model with a diffusion factor, it is possible to predict the cure kinetics of each catalytic system over the whole range of conversion. (C) 1998 John Wiley & Sons, Inc. [References: 15]