A triple‐shape memory material fabricated by in situ crosslinking of poly(butylene adipate‐co‐terephthalate)/ε‐polycaprolactone via electron‐beam irradiation and its triple‐shape memory effects

• Published in: Journal of applied polymer science 2020-04, Vol.137 (16), p.n/a
• Main Authors: Wu, Xianyou, Qian, Jing, fu, Chao, Tan, Zhongyang, Gao, Yixing, Ma, Antong, Nie, Wei, Ran, Xianghai
• Format: Article
• Language: English
• Subjects: Crosslinking; Electron beams; Electron irradiation; electron‐beam irradiation; Elongation; Heating rate; in situ crosslink; Interfacial strength; Materials science; Polycaprolactone; Polymers; Recovery; self‐stability; Shape effects; Shape memory; Tensile tests; Terephthalate; triple‐shape memory effect
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.48588

ABSTRACT In this work, we fabricated a triple‐shape memory polymeric material though in situ crosslinking of poly(butylene adipate‐co‐terephthalate)/ε‐polycaprolactone blends induced by electron beam irradiation. The intrinsic property of irradiation crosslinking, crosslinking rule in this heterogeneous system, formation of interfacial bridge molecular, and the resulted interfacial strength were investigated. No obvious interfacial slips were observed in tensile test, and the elongation at break was above 900%. The high‐temperature relaxation and recovery experiments at nonlinear region confirmed the excellent hyperelasticity and recovery ratios (Rr) can be as high as 95% for samples irradiated above 96 kGy. The mismatch between heating rate and relaxation kinetics resulted in both instable temporary shapes and heating‐mode dependent recovery behavior during the recovery process. Self‐stability of the temporary shape at middle temperature was also emphasized in view of the phenomenon that the second Rr was above 100% in our experiments. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48588. The triple‐shape memory materials were fabricated as polymer blends via E‐B irradiation. Before the formal triple‐shape memory effect (TSME) test, irradiation crosslinking kinetics, crosslinking rule of the blends, and crosslinking nature were investigated. All obtained materials of blends have TSME, excellent mechanical properties, and interfacial strength, especially for irradiated sample with blending ratio near 1/1, excellent TSME and large deformability were integrated. As shown in the figure, the obtained sample can be programmed into different temporary shapes with large deformation, and then recovers to the permanent shape in stages when it is heated successively from −10 °C to 70 and 160 °C.