Tunable Triple-Shape Memory Composite Fabricated By Selective Crosslinking Of Polycaprolactone/Poly(Butylene Adipate-Co-Terephthalate)/Bentonite

In this work, we fabricated a triple-shape memory polymeric composite (TSMPc) by electron beam irradiation of epsilon-polycaprolactone (epsilon-PCL)/poly(butylene adipate-co-terephthalate) (PBAT)/bentonite(50/50/4) (wt %). The 95 +/- 5 kGy was confirmed to be the saturated irradiation dose by both high-temperature storage modulus and the equilibrated relaxation modulus at nonlinear elastic region. Further results demonstrated that sample exposed to 41.4 kGy exhibited excellent triple-shape memory effect (TSME) though there existed slight plastic flow in PBAT. The two fixity ratios and total recovery ratio can be as high as 99.9, 98.3, and 94.7%. Besides, the strength of irradiated PBAT was improved because of the synergistic mechanical coupling effect from PCL and bentonite. In the meantime, this synergistic effect also improved the integral TSME and the stability of all shapes. Eventually, we made a comparison among the controllable factors, the crosslinking density and amount of deformation Delta epsilon(B -> C) were believed to have more influences on the stability of temporary shapes and the recovery behavior during the shape memory cycle "A -> B -> C -> B-r -> A(r)." (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 137, 48577.