Simultaneous interpenetrating polymer networks of epoxy and N-phenylmaleimide-styrene copolymers

Ductile thermoplastic N-phenylmaleimide-styrene copolymers (PMS) have been introduced into diglycidyl ether of bisphenol A (epoxy) by a simultaneous polymerization technique. The tensile strength and fracture toughness increased with increasing PMS content and reached a maximum value at a PMS/epoxy ratio of about 20/80 (w/w). The mechanical properties decreased significantly beyond that ratio, because of phase inversion.