Synthesis of PLA-based thermoplastic elastomer and study on preparation and properties of PLA-based shape memory polymers

Abstract

As a new functional polymer material, shape memory polymer (SMP) has many advantages, and can be widely used in medical devices, textiles, aerospace and other fields. For thermal response SMPs, temporary deformation can be stored under external force above Tg with a rapid cooling down to below Tg or Tm, and when heated again to the critical temperature point, they return to their original shape. In this paper, shape memory poly (lactic acid) (PLA) block copolymers were prepared from a chain extension reaction of PLA with poly(ε-caprolactone) diol (PCL-OH). Using hexamethylene diisocyanate (HDI) as a chain extender, the molecular weight of the prepolymer could be greatly increased by melt chain extension. Polylactic acid thermoplastic elastomer (PLAE) synthesized by chain extension reaction is soft and tough, similar to thermoplastic polyurethane (TPU). Polylactic acid-based shape memory polymers with good shape memory properties can be obtained by blending PLAE with PLA. The shape memory property test showed that the polylactic acid-based shape memory polymer was successfully prepared, and the recovery rate of the polylactic acid-based shape memory polymer could reach to approximately 80%. Besides, we also did thermal and microstructural analysis of the blend material. Due to their good biocompatibility and biodegradability, PLAE and PLA/PLAE will have potential applications in biomedical implant materials, engineering plastics, and textiles.