Polyurethanes Based on Polylactic Acid for 3D Printing and Shape-Memory Applications
Shaoyun He, Shikai Hu, Yaowen Wu, Ruiheng Jin, Zhihao Niu, Runguo Wang, Jiajia Xue, Sizhu Wu, Xiuying Zhao, Liqun Zhang
Abstract
Polylactic acid (PLA) has received increased attention in the development of shape-memory polymers and biomedical materials owing to its excellent physical properties and good biocompatibility and biodegradability. However, the inherent brittleness and high shape-recovery temperature of this material limit its application in the human body. Herein, we fabricated a PLA-based thermoplastic polyurethane (PLA-TPU) prepared from modified PLA-diol, dicyclohexylmethane-4,4′-diisocyanate, and 1,4-butanediol to solve the limitations of pure PLA. The glass transition temperature (Tg) of the designed TPU can be tailored from 6 to 40.5 °C by adjusting the content of hard segments or molecular weight of soft segments. The shape of the designed TPU can be fixed at room temperature and recovered at temperatures above 37 °C. Moreover, the prepared PLA-TPUs exhibited recyclability, three-dimensional printing capability, non-cytotoxicity, blood compatibility, and biodegradability. The shape of PLA-TPU/nano-Fe3O4 composites can be recovered by exposure to near-infrared light. These results collectively indicate that PLA-TPUs and their composites may have potential applications as intelligent flexible medical scaffolds for surgical and medical implantation equipment.