Electro-induced two-way shape memory effect from novel interpenetrating polymer networks based on poly(benzoxazine/urethane) reinforced with carbon fiber felt

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 (T<inf>g</inf>) 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.