Design of heat‐triggered shape memory polymers based on ethylene‐acrylic acid copolymer/nitrile‐butadiene rubber thermoplastic vulcanizates

Abstract

AbstractHeat‐triggered shape memory polymers (HSMPs) consisting of ethylene‐acrylic acid copolymer (EAA) and nitrile‐butadiene rubber (NBR) were fabricated by peroxide‐induced dynamic vulcanization; meanwhile, in order to realize rapid and reconfigurable shape fixity and shape recovery, a facile and effective strategy was designed. Morphological structure and interface interaction are decisive factors for HSMPs, the FE‐SEM images showed the average diameter of NBR particles in EAA/NBR TPVs was 5 to 8 μm and the strong interface interaction between EAA matrix and NBR particles provided critical assistance in keeping the temporary shape of deformed rubber particles and storing stronger elastic driving force. The shape memory behavior of EAA/NBR TPVs was characterized and the result demonstrated that excellent shape‐fixity (>91%), shape‐recovery (>93%), and fast recovery speed (<30 s) could be obtained at suitable deformation temperature of 95°C. The results of dynamic mechanical analysis and shape memory research showed that the high modulus value supported the improvement of shape‐fixity ratio and the appropriate ratios of EAA/NBR TPVs were the key factors for excellent shape memory performance. The novel HSMPs expected to open up potential applications in the field of sensors and self‐assembling smart devices.