Abstract

Novel two-way shape memory polymer composites (2WSMPC) consisting of interpenetrating polymer networks (IPNs) of poly(benzoxazine/urethane) reinforced with carbon fiber felt (CFF) were developed in this work. Sequential curing, i.e., moisture curing of urethane followed by thermal curing of benzoxazine (BA-a) was used to synthesize IPNs with molecular phase separation. The thermomechanical properties and two-way shape memory effect (2WSME) of the IPNs were systematically investigated by varying the urethane content. It was found that the glass transition temperature (Tg) and 2WSME of the IPNs based on poly(benzoxazine/urethane) improved by optimizing the urethane content. Moreover, the electro-induced shape memory performance was found to be dependent on the CFF reinforcement. The results showed that the developed IPNs reinforced with CFF triggered by electric current exhibited high two-way shape memory performance, i.e., a fixity at room temperature (RT) of 97–98%, recovery to original shape at high temperature of 97–98%, and those to temporary shape at RT of 92–97%. The findings revealed that the electro-induced two-way shape memory composite from CFF-reinforced poly(benzoxazine/urethane) is a promising candidate for smart electric circuit breaker applications with highly stable reverse recovery between original and temporary shapes up to 20 cycles.