The dynamic mechanical properties and morphology of binary copolymer networks (BCN's) of vinyl-terminated polyurethane (VTPU) prepolymer and vinyl monomers such as styrene(St)

methyl methacrylate(MMA)

vinyl acetate(VAc) and butyl methacrylate(BMA) were studied. All the BCN's samples have semicompatible feature on the dynamic mechanical spectroscopy. The compatibility between components increases with the increasing cross-link density due to the increase in the entropy of mixing. The amount of soluble species varies with composition of BCN's. The sol fraction can improve the compatibility between com-ponents.