聚L-乳酸的合成与降解性能研究

Study on synthesis and heat degradation behavior of poly(L-lactide)

将L-丙交酯以辛酸亚锡为催化剂,经开环聚合制备了聚L-乳酸（PLLA）。通过正交试验分析了反应温度、聚合时间和催化剂用量等因素对产物相对分子质量的影响,确定了最佳聚合条件：聚合温度为140℃,聚合时间为36h,催化剂质量分数为0.02%,这时聚乳酸的相对分子质量可达到2.2×10^5。研究了聚乳酸在0-120min和180-210℃的条件下热降解后的相对分子质量与端羧基含量的变化。另外,采用FTIR、XRD等测试手段研究了聚乳酸的结构。

Poly （L-lactide） （PLLA） was prepared by ring-opening polymerization of L-lactide with catalyst stannous octanoate. The effects of catalyst, temperature and time of polymerization on molecular mass of product were researched by orthogonal test. The results indicated the best reaction condition, while the temperature is 140 ℃, the catalyst amount is 0. 02% （based on L-lactide） and the polymerization time is 36 hours, the molecular mass of obtained PLLA can be reached 220 000. The change of molecular weight and carboxy terminal group content were studied for polylactide at 0-120 rain and 180-210℃. The structure of PI.LA was studied by FTIR and XRD.