Mechanically Robust, Reprocessable Shape Memory Fluorosilicon Materials Using β-H Elimination Reaction and in Situ Interfacial Compatibilization
Recyclable polyvinylidene fluoride/silicone rubber (PVDF/SR) thermoplastic vulcanizates (TPVs) containing a high mass ratio of SR (50%) with excellent mechanical performances and shape memory behavior were fabricated. The inert PVDF was first dehydrofluorinated via β-H elimination reaction to introduce reactive double bonds. Then, the functional groups were initiated by dicumyl peroxide (DCP) during dynamic vulcanization to realize interfacial grafting (SR-g-PVDF) simultaneously. In situ grafted PVDF chains tightly bridge the immiscible phases, leading to the excellent interfacial adhesion. Consequently, the tensile strength, elongation at break, and tensile toughness were significantly increased to 14.5 MPa, 174.6%, and 12.3 kJ/m3, respectively, which were almost 2.0, 13.6, and 10.3 times than that without interfacial grafting reaction (7.2 MPa, 12.8%, and 1.2 kJ/m3). Also, their excellent mechanical properties were almost perfectly maintained after multiple repetitive processing. Furthermore, the chemical anchoring structure of SR-g-PVDF across the interface could effectively and quickly transfer the force, contributing to the shape memory performances. The obtained TPVs (m60 and m80) showed an impressive shape recovery ratio (>80%) even after two fixing-recovery cycles.
危险品化学品经营许可证（带存储）