Preparation and Properties of Polylactic Acid‐Based Shape Memory Composites

ABSTRACT In this paper, poly(lactic acid) (PLA)/thermoplastic polyurethane (TPU) binary blend composites were prepared by a melt blending method using PLA as the substrate and TPU as the toughening component, to which carbon nanotubes (CNT) were added, and PLA/TPU/CNT shape memory composites with light‐responsive and heat‐responsive shape memory properties were prepared. The mechanical properties, micro‐morphology, light‐responsive, and heat‐responsive shape memory properties of the prepared composites were investigated. The results showed that the toughening effect of thermoplastic polyurethane was best when the ratio of PLA to TPU was 8:2, based on which the light‐converting particle CNT was added to prepare the light‐ and heat‐responsive PLA/TPU/CNT ternary composites. The better the dispersion of CNT, the better the mechanical properties, stiffness, and shape memory properties of the composite. When the CNT content is 3 wt%, the shape memory performance is the best, and the composite has fast‐response optical and thermal shape memory properties and high recovery ability, which can reach 100% under continuous light and heating conditions. Based on the composites, opto‐thermal responsive smart packaging boxes and flower‐shaped series–parallel integrated switch models were designed, expanding the applications of composites in the fields of smart packaging materials and electronic devices.