A novel adamantane-based polyurethane with shape memory effect

A novel adamantane-based polyurethane (AdPU) was synthesized via efficient ring-opening polymerization of 1,3,5,7-tetrahydroxyadamantane with ε-caprolactone followed by one-step polymerization of poly(ε-caprolactone) (PCL2000) with 1,6-hexamethylene diisocyanate (HDI). The incorporation of 1,3,5,7-tetrahydroxyadamantane enhanced the thermal stability of AdPU. It was found that AdPU was composed of a crystalline soft phase and an amorphous hard phase; and the aggregation of segments could form nano-sized crystal fibers by controlling the drying conditions. Finally, shape memory effect tests showed that AdPU has thermal-induced shape memory effect with good shape fixation and 85% shape recovery. This work opens a new avenue to design polyurethane frameworks with cubic geometry structure for shape memory applications.