Kinetics of anhydride curing of isophthalic diglycidyl ester using differential scanning calorimetry

Abstract

Abstract The cure reaction of a model diglycidyl ester, bis‐(2,3‐epoxypropyl)‐1,3‐benzenedicarbox‐ylate, with hexahydrophthalic anhydride as the curing agent and benzyldimethylamine as the catalyst, was studied by differential scanning calorimetry using an isothermal approach over the temperature range 100–135°C. The results indicate that the cure reaction is au‐tocatalytic in nature and does not follow simple n th‐order kinetics. A semiempirical equation for autocatalytic systems containing two rate constants and two reaction orders, viz., 0.5 and 1.5, provided a good phenomenological description of the cure kinetics up to the point of vitrification. With the inclusion of a diffusion factor into this model, it was, however, possible to predict with precision the cure kinetics over the whole range of conversion covering both pre‐and postvitrification stages and over the entire temperature range of 100–135°C employed for isothermal curing. © 1993 John Wiley & Sons, Inc.