高分子量聚L-乳酸热降解回收L-丙交酯

本文综述了高分子量聚L-乳酸(Poly(L-lactide), PLLA)经热降解直接回收L-丙交酯的研究进展。纯PLLA的热降解为无规反应，经添加金属类催化剂后，PLLA则可获得以L-丙交酯为主的热降解产物。本文介绍了聚乳酸热降解的反应机理，详细阐述了添加的金属催化剂的种类，及其催化PLLA热降解生成L-丙交酯及发生消旋化作用的机理。经PLLA热降解直接回收L-丙交酯技术的研究，可缩短PLLA再循环使用周期，既降低生产成本，又充分利用资源，达到促进发展循环经济的目的。

Thermal Degradation of Poly(L-lactide) with High Molecular Weight into L-Lactide

The recent progress of direct recycling of L-lactide from poly L-lactide (PLLA) with high molecular weight through thermal degradation is reviewed. The thermal degradation of pure PLLA proceeds mainly through a random scission reaction, but PLLA thermally degrades with the metal catalyst through a dominant degradatin pathway, producing principally L-lactide. In this paper, not only the mechanism of thermal degradation of polylactide is introduced, but also the kinds of metal catalysts, their influence on L-lactide formation and racemization through thermal degradation of PLLA are referred. Research on the direct recycling of L-lactide from PLLA with high mulecular weight through thermal degradation, which could shorten the recycling use period of PLLA, reduce production cost, make full use of the resources and achieve the development of recycling economy.