Compatibility of Polyurethane/(vinyl ester resin)(ethyl acrylate) Interpenetrating Polymer Network

A novel polyurethane/poly(vinyl ester resin) interpenetrating polymer Network(PU/VER IPN), was synthesized at room temperature by polymerizing ethyl acrylate(EA) instead of the conventionally styrene(St) as a comonomer. The respective compatibilities of PU/VER(EA)IPN and PU/VER(St)IPN were studied by ATR-FT/IR, TEM, AFM, DSC and DMA. The results showed that, compared with PU/VER(St)IPN, the degree of carbonyl hydrogen bonding in PU/VER(EA)IPN increased because EA substituted for St, resulting in better compatibility of PU/VER(EA)IPN. PU/VER(EA)IPN showed a nanometer scale phase range and a dual continuous microstructure, while the phase range of PU/VER(St)IPN was 200–500 nm. Furthermore, DSC showed that PU/VER(EA)IPN had one obvious Tg, while PU/VER(St)IPN had two Tgs. The compatibility of PU/VER(EA)IPN was further detected quantitatively. In addition, the 60:40 PU/VER(EA)IPN had a predominant damping peak and a shoulder damping peak which were closer than the two corresponding peaks of PU/VER(St)IPN. PU/VER(EA)IPN had higher tanδ, E″, E′, TAandLA for a broad range of temperature, all indicating better compatibility and damping properties. Their mechanical properties were also studied preliminarily.