Tunable shape recovery of polymeric nano-composites

Polymeric nano-composites of different compositions were synthesized by incorporating cellulose nano-whiskers (CNW) into shape memory polyurethane (SMPU). The morphology and the dynamic mechanical properties of the composites were investigated by Scanning Electronic Microscopy (SEM) and Dynamic Mechanical Analysis (DMA). After extension in a specifically explored thermal-aqueous process, the thermal-induced shape recovery of the composites in the dry-state was found being negative proportional to the CNW content. This finding may provide a composite approach, rather than molecular design, to tune the shape memory behaviors of the conventional shape memory polymers and may contribute to the application of nano-technology in smart materials field. (C) 2011 Elsevier B.V. All rights reserved.