Quick water‐responsive shape memory hybrids with cellulose nanofibers

A type of quick water-responsive shape memory hybrids is fabricated by introducing cellulose nanofibrous mats as the filler in a polymeric matrix. Cellulose nanofibrous mats are obtained through hydrolyzing electrospun cellulose acetate (CA) nanofibers, then casted in thermoplastic polyurethane (TPU) solution to form the hybrids. The quick shape memory behavior of the formed hybrids is demonstrated using dynamic mechanical analysis (DMA) and stress–strain cyclic test. According to a predetermined protocol, the hybrids present desirable shape fixation and recovery, and the elastic modulus (E′) is shown to be responsive promptly and reversibly against drying and wetting cycle. Shape memory mechanism of the hybrids involves the reversible and competitive hydrogen bonds within cellulose before and after water immersion as well as the entropy elasticity of the TPU matrix. This study can pave a way to design novel smart materials by facile methods through incorporating natural nanomaterials as water sensitive fillers. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016