CURE KINETICS AND INTER-DOMAIN ETHERIFICATION IN AN AMINE-CURED PHENOXY EPOXY SYSTEM/

The aim of this study was to examine possible effects of the hydroxyl group (-OH) in phenoxy-type polymers on the cure reactions and network morphology of a crosslinking epoxy system, tetraglycidyl-4,4'-diamino diphenylmethane (TGDDM) with diaminodiphenylsulfone (DDS). Similar to the case for a pure, unmodified TGDDM/DDS epoxy counterpart, an autoca talytic reaction kinetic model was found to describe the cure behaviou r of the phenoxy/TGDDM/DDS mixtures up to the vitrification point. At the early stage of cure, the -OH group in the phenoxy might exert a ca talytic effect for epoxide ring opening between epoxy and the amine. S ubsequently, at later cure stages where phase domain boundaries were f orming and the amine groups were largely depleted, the -OH groups of t he phenoxy phase domain began to react with the residual epoxide group s in the epoxy domains. It is this later-stage reaction that led to in terlinking chemical bonding between the phenoxy and epoxy phases at th e domain boundaries. (C) 1998 Elsevier Science Ltd. All rights reserve d.