POLYCARBONATE EPOXY SEMIINTERPENETRATING POLYMER NETWORK .1. PREPARATION, INTERACTION AND CURING BEHAVIOR/

An epoxy based on the diglycidyl ether of bisphenonl-A (DGEBA) has bee n modified with polycarbonate (PC) and cured with 4,4'-diaminidiphenyl sulfone (DDS) and maleic anhydride (MA). The chemical interaction betw een the PC and epoxy resin during the melt-mixing process and its effe cts on the physical characteristics of the PC have been investigated p rior to the curing process. The curing kinetics of the neat resin and of PC/epoxy blends were analysed in detail by dynamic differential sca nning calorimetry. The results showed that the PC usually has no effec t or has promoting effects on the curing reaction for amine hardener b ecause of the in situ curing mechanism, except for diffusion control. The presence of quaternary ammonium salts catalysing the PC-epoxy reac tion resulted in a two-step curing behaviour, but its curing kinetics are similar to those of the neat resin. For MA curing systems, a diffe rent effect caused by PC and catalyst is associated with a different i nteraction among the reactants. (C) 1996 Published by Elsevier Science Ltd.