Fabrication of Novel Thermoplastic Vulcanizates Based on Ethylene-Vinyl Acetate Copolymer/Chloroprene Rubber with Heat-Triggered Shape Memory Behavior

In this paper, a simple and effective strategy was adopted to design a novel heat-triggered shape memory polymers (HSMPs) based on ethylene-vinyl acetate copolymer (EVA)/chloroprene rubber (CR), which can achieve speedily reconfigurable shape fixity and recovery. The morphology image of the HSMPs presented a sea-island structure, and the diameter of the CR particles was 4~8 μm. In the differential scanning calorimetry characterization, it was found that the high EVA content had a high melting transition enthalpy, and the switching temperature was closely related to the melting temperature.The shape memory measurement results showed the shape fixation rate (>95%), shape recovery rate (>95%) and recovery time (<30 s) of these novel HSMPs at suitable environment of 75°C, which can be used as an ideal shape memory material; meanwhile, the optimum weight ratio of EVA to CR and switching temperature were the key factors that determine the shape memory property. Its unique switching temperature ability and outstanding shape memory characteristics were widely used in the field of temperature sensors and automotive engineering.