Graphene-crosslinked two-way reversible shape memory polyurethane nanocomposites with enhanced mechanical and electrical properties

Highly flexible, conductive, and two-way reversible shape memory polyurethane nanocomposites were prepared with the in situ synthesized method, containing different graphene nanosheet contents ranging from 1.0 to 8.0 wt%. The dispersion of the nanocomposites in the polymer was monitored by scanning electron microscopy and thermal properties, mechanical properties, electrical properties, shape memory properties were comparatively investigated. The results showed that the nanocomposite was more stable when the content of graphene is 2 wt% in the crosslinked network structure. In comparison to pristine polyurethane, the graphene crosslinked polyurethane composite exhibited better thermostability, breaking stress, and exceptional elongation-at-break. The resulting composite exhibited 93 % shape fixity, 95 % shape recovery of 2.0 % loading, and fast electroactive shape recovery rate. Moreover, the polymers also showed good reversible two-way shape memory behaviors, thus it could be a promising material for the fabrication of graphene-based actuating devices.