Polydiacetylene-Polyurethane Crisscross Elastomer as an Intrinsic Shape Memory Conductive Polymer.

Owing to the high phase transition temperature and incompatibility with thermoplastic elastomers, conjugated polymers are hardly formulated as shape memory materials. This work presents a crisscross polymer composed of polyurethane and polydiacetylene. Phase separation is completely avoided based on the photoinduced polymerization of polydiacetylene from polyurethane chains. The two backbones are intercrossed and covalently linked to each other. Particularly, polyurethane acts as a soft segment to provide elastic performance, and the rigid polydiacetylene provides conductive pathways. Such a crisscross topology, combined with soft and rigid compositions, renders the possibility to serve the polymer as an intrinsically elastic conductive polymer. Intriguingly, the polymer possesses shape memory performance, meanwhile retaining the reliable conductivity. Electrical tests demonstrate that the shape memory conductive polymer is one attractive candidate for exploiting shape-customized strain sensors.