Conducting shape memory polyurethane-polypyrrole composites for an electroactive actuator

Electroactive shape memory composites were prepared using polyurethane block copolymer and conducting polypyrrole by chemical oxidative polymerization. The electrical conductivity, thermal and mechanical properties, and morphology of the composites were investigated, and a voltage-triggered shape memory effect was demonstrated. The polyurethane synthesized had a transition temperature near 46 T. The presence of polypyrrole increased the conductivity of the composites, and a high conductivity of the order of 10(-2) S/cm was obtained at 6-20 wt.-% polypyrrole. Such a conductivity of composites was enough to show electroactive shape recovery by heating above the transition temperature of 40-45 degrees C due to melting of the polycapro-lactone soft segment domain. Thus a good shape recovery of 85-90% could be obtained in the shape recovery test with bending mode when an electric field of 40 V was applied.