中文摘要：

通过开环聚合法，利用D，L-丙交酯合成不同规整度（Xo）的左旋聚乳酸PLLA和右旋聚乳酸PDLA。用溶液浇铸法制得不同规整度的聚乳酸立构复合物SC-PLA，并在50℃缓冲溶液中进行降解。通过分析剩余质量、溶液pH值、热性能（DSC）、表面形貌（SEM）、电离子喷雾质谱（ESI-MS）等评价SC-PLA的降解性能。结果表明：相同规整度时，SC-PLA降解速率小于PL-LA，但pH值变化大于PLLA，立构复合物SC的存在使材料比常见PLLA更耐水解；立构规整度下降会使SC-PLA的结晶度降低，材料的降解速率加快；降解使材料的结晶度上升，立构复合物晶体SC与均聚物晶体HC熔点降低；高规整度SC-PLA相对于相同规整度PLLA及低规整度SC-PLA，其降解产物分子链长度更短。

英文摘要：

PDLA and PLLA with various chain stereo-regularity （XD） were obtained through ring-opening po- lymerization. PDLA and PLLA with similar XD were blended with 1 ： 1 weight ratio and then films were obtained through solution cast. They were subjected to hydrolytic degradation in buffer solution at 50 ℃, and the degradation processes were monitored by following mass loss, pH of the aging medium, thermal properties, surface changes,and degradation product patterns analysis. The results show that SC-PLA is more stable during aging process compared with common PLLA which has the same stereo-regularity. The decrease of stereo-regularity of SC-PLA leads to the decrease of crystallinity and accelerates the degradation process. The melting temperatures of both homocrystallites and stereo-complex crystallites of these samples shift to lower temperature while the crystallinity increases with the time. Hydrolysis of SC-PLA （XD = 100%） results in shorter but more acidic degradation products, compared to PLLA with the same XD and SC-PLAs with a lower XD.