Fabricated Biobased Eucommia Ulmoides Gum/Polyolefin Elastomer Thermoplastic Vulcanizates into a Shape Memory Material

Abstract

Partially biobased thermoplastic vulcanizates (TPVs) with shape memory properties were prepared by in situ dynamic vulcanization of eucommia ulmoides gum (EUG) and polyolefin elastomer (POE). The cross-linked EUG phase dispersed in POE matrix acted as a framework structure throughout the POE phase, which limited irreversible deformation of POE and provided sufficient resilience force to drive the POE molecular chains to recover their initial shape. The shape memory results demonstrated that EUG/POE TPVs exhibited excellent shape memory properties with high shape fixity and shape recovery rate (all above 95%). The EUG with the dimensions of 0.4–1.6 μm dispersed in the POE matrix, and the more EUG phase resulted in large EUG aggregates. The cross-linked EUG phase considerably improved the permanent deformation of POE, and the tensile set linearly decreases from 134% to 4% with increasing EUG contents. The mechanical and shape memory properties of EUG/POE TPVs changed little after being reprocessed twice, exhibiting good reprocessability. All of these remarkable advantages make EUG/POE TPVs good candidates for shape memory materials.