开环聚合-固相缩聚法制备立体嵌段聚乳酸

发布时间：2018-04-26 02:14

本文选题：聚乳酸 + 立体嵌段聚乳酸　；参考：《功能高分子学报》2017年01期

【摘要】：首先,采用乳酸为引发剂,辛酸亚锡为催化剂,引发丙交酯开环聚合制得具有缩聚活性的L-聚乳酸和D-聚乳酸;然后,将两者熔融共混后进行固相缩聚,合成了一系列立体嵌段聚乳酸。采用核磁共振(NMR)、凝胶渗透色谱(GPC)及差示扫描量热仪(DSC)分析了产物的链结构、重均分子量、热性能,并探讨了均相晶体和立体复合晶体共存情况下的固相缩聚机理。结果表明,固相缩聚产物分子量增长的适宜反应条件为:反应时间30h,较低的催化剂含量,L-聚乳酸质量分数为80%。L-聚乳酸和D-聚乳酸共混物较低的初始立体复合晶体结晶度有利于后续固相缩聚过程中产物分子量的增长;固相缩聚不仅发生在异链之间,而且也发生在同链之间。
[Abstract]:Firstly, L- polylactic acid and D- polylactic acid were prepared by ring-opening polymerization of lactide with lactic acid as initiator and stannous octanoate as catalyst. A series of solid block poly (lactic acid) was synthesized. The chain structure, weight average molecular weight and thermal properties of the products were analyzed by NMR, GPC and differential scanning calorimeter (DSC). The mechanism of solid phase Polycondensation in the presence of homogeneous crystals and stereoscopic composite crystals was discussed. The results show that The optimum reaction conditions for the molecular weight increase of solid phase Polycondensation products are as follows: reaction time is 30h, and the lower catalyst content is 80. L- polylactic acid and D- polylactic acid blends. The crystallinity of the initial stereoscopic composite crystals with lower mass fraction of 80. L- poly (lactic acid) and D- polylactic acid is favorable. The increase of the molecular weight of the product during the subsequent solid phase Polycondensation; Solid phase Polycondensation occurs not only between different chains, but also between the same chains.
【作者单位】：华东理工大学材料科学与工程材料学院;上海科院生物材料有限公司;
【基金】：国家自然科学基金(51173041)
【分类号】：O633.14

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