Solvent‐Responsive Shape Memory Porous Semicrystalline Thermoplastic Polyurethane

ABSTRACT Solvent‐responsive shape memory polymers are smart materials that can recover their original shape upon exposure to solvents. However, the shape memory properties of porous materials have not been fully investigated. Here, shape memory porous semicrystalline thermoplastic polyurethane (TPU) was prepared by the way of salt‐leaching. The shape memory behavior of porous TPU in ethyl acetate (EA) is investigated. The EA molecules remarkably increase the mobility of amorphous chains of TPU, and the step‐like glass transition disappears in DSC curves. The dissolution of partial crystalline TPU drives it to recover without obvious swelling. The dissolution of partial crystalline identified by XRD increases as the immersion time increases and improves the shape recovery ratio. The greatly increased specific surface area of porous TPU does not reduce the recovery time, although the interconnected porous structure is beneficial to the penetration of EA. The uniformly distributed porous structure allows porous TPU to maintain break strain and modulus comparable to those of dense TPU. These results reveal that the solvent‐responsive shape memory properties and mechanical properties of porous materials are closely related to the interaction of solvent molecules and polymeric chains.