LAUSR

Abstract In order to reveal the effect of curing reaction and such physical state as gelation and vitrification on the microstructure and the resulting thermo-mechanical properties, a series of epoxidized hyperbranched polyurethane (EHPU) modified benzoxazine resin (BZ) blends (BE) were fabricated. The curing reaction between BZ and EHPU was investigated by nonisothermal DSC, FTIR and isothermal rheology. The self-polymerization or the copolymerization of BZ and EHPU was successfully realized via tuning its curing cycle at different curing temperature. The ether cross-link was realized from the copolymerization between oxazine ring and epoxy groups, which can dilute the rich benzene ring of BZ and weaken the hydrogen bonding of pure BZ. As for BE with 10 wt% of EHPU, both a high cross-link density and an excellent thermomechanical property can be obtained with the curing cycle of entering the vitrification state in the initial stage and then transferring it into the post-curing. As thus, the study provides a novel strategy in fabricating a dense network via tuning the curing reaction and physical state.