Super-tough poly(lactic acid) thermoplastic vulcanizates with heat triggered shape memory behaviors based on modified natural Eucommia ulmoides gum

摘要

To take full advantage of renewability and environmental friendliness of poly(lactic acid) (PLA) and natural Eucommia ulmoides gum (EUG), PLA was used with epoxidized natural Eucommia ulmoides gum (EEUG) to prepare novel bio-based TPVs via a dynamic vulcanization method. The PLA/EEUG TPVs exhibited not only super toughness but also excellent shape memory behaviors, which might provide a new approach for the industrialization of super-toughened and bio-based shape memory TPVs. It was found that the in situ compatibilization achieved by grafting reaction between PLA and EEUG and "sea-sea" phase structure were vital for the enhancement of toughness and shape memory properties. The TPV with 40 wt% EEUG displayed not only super toughness with the impact strength of 47.3 kJ/m(2) (nearly 20 times than that of neat PLA 2.4 kJ/m(2)) but also the best shape memory properties, with a shape fixity ratio and shape recovery ratio of 99.28% and 94.19%, respectively. These bio-based shape memory TPVs would show great application potential in smart medical devices and 3D printing materials.