KINETIC-STUDY OF THE EFFECT OF CATALYSTS ON THE CURING OF BIPHENYL EPOXY-RESIN

The investigation of cure kinetics of biphenyl epoxy (4,4'-diglycidylo xy-3,3',5,5'-tetramethyl biphenyl)dicyclopentadiene type phenolic resi n system with different kinds of catalysts was performed by a differen tial scanning calorimeter using an isothermal approach. All kinetic pa rameters of the curing reaction including the reaction order, activati on energy, and rate constant were calculated and reported. The results indicate that the curing reaction of the formulations using triphenyl phosphine (TPP), 1-benzyl-2-methylimidazole (1B2MI), and tris(4-methox yphenyl)phosphine (TPAP) as a catalyst proceeds through an nth-order k inetic mechanism, whereas that of the formulations using diazabicyclou ndecene (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 mode l or an autocatalytic model with a diffusion factor, it is possible to predict the cure kinetics of each catalytic system over the whole ran ge of conversion. (C) 1998 John Wiley & Sons, Inc.