Cure behavior of an interpenetrating diglycidyl ether of bisphenol A/poly(ethylene oxide) miscible system

Differential scanning calorimetry (DSC) was performed to investigate the cu re behavior of epoxy networks of diglycidyl ether of bisphenol A/poly(ethyl ene oxide) (DGEBA/PEO) cured with 4,4'-diaminodiphenyl sulfone (DDS). An in teresting miscibility has been recently reported for DGEBA/PEO networks of a semi-interpenetrating structure cured with aromatic amine. This study foc used on the cure behavior and effects of miscible polymer diluents on cure kinetics. The physical miscible state between the poly mer and epoxy was fo und to exert no alteration on the cure mechanism, which remained to be auto catalytic for DDS amine-curing of all DGEBA/PEO mixtures as well as the pur e DGEBA. The PEO component, being in a miscible state with the epoxy/DDS th roughout the cure, acted as a diluent for the reactive DGEBA epoxy and DDS components. The dilution effect could be partially compensated by raising t he DDS/epoxy ratio in proportion to increased PEO fraction in DGEBA/PEO/DDS mixtures.