Design of ethylene-methyl acrylate copolymer/chloroprene rubber thermoplastic vulcanizates as heat-triggered triple-shape memory polymers
Dazhi Zhu, Junhao Wang, Yongheng Sun, Jianqiang Chu, Zhaobo Wang
Vol. 19., No.4., Pages 361-371, 2025
DOI: 10.3144/expresspolymlett.2025.27
DOI: 10.3144/expresspolymlett.2025.27
Corresponding author: Zhaobo Wang 
GRAPHICAL ABSTRACT
ABSTRACT
In this research, heat-triggered triple-shape memory polymers (TSMPs) based on the ethylene-methyl acrylate copolymer (EMA)/chloroprene rubber (CR) thermoplastic vulcanizates (TPVs) were prepared by dynamic vulcanization successfully; meanwhile, an effective and facile triple-shape memory strategy was designed to realize the efficient and stable shape fixity and recovery of two temporary shapes. The field-emission scanning electron microscope images showed that EMA/CR TPV surface was a sea-island structure with the CR particle size ranging from 3 to 6 μm. Differential scanning calorimeters and X-ray diffraction were used to investigate the crystallization behavior of both EMA and CR. These served as a significant basis for the two temporary shapes: fixity and recovery. The results of triple-shape memory tests showed that the EMA/CR TPV had excellent triple-shape memory properties, where the first shape fixity ratio was higher than 89% and both the first shape recovery ratio and second shape recovery ratio could be higher than 95%. It can be observed that the EMA/CR TPV exhibited rapid shape recovery speed with the first shape recovery time of 10 s and the second shape recovery time of 20 s, respectively. This research presents a novel approach to extending the application of TPV in the field of smart devices, endowing them with excellent mechanical and triple-shape memory properties.
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