【作者】 尹会会； 王锐；

【Author】 YIN Huihui;WANG Rui;Department of Polymer Science and Materials,State Key Laboratory of Polymer Materials Engineering,Sichuan University;Department of Materials Science & Engineering,Beijing Institute of Fashion Technology;

【机构】 四川大学,高分子科学与工程学院高分子材料工程国家重点实验室； 北京服装学院,材料科学与工程学院；

【摘要】 <正>聚乳酸(PLA)可由玉米、马铃薯等可再生资源提取的淀粉转化为葡萄糖,进一步发酵成的乳酸作为原料聚合而成,具有良好的生物相容性及可降解性,聚乳酸降解速率较慢,一般大于24个月。聚乙醇酸(PGA)是一种用于可吸收手术缝合线的聚合物,它也是最早用于骨折固定材料的可吸收聚合物之一,而聚乙醇酸降解速度较快,一般为6~12个月。因此,可以通过控制乳酸-乙醇酸共聚组成比调节PLGA的降解速度。本研究采用均聚-共聚法合成b-PLGA,首先,以乳酸(LA)及乙醇酸(GA)为单体,分更多还原

【Abstract】 A two-step direct melt copolymerization process of L-lactic acid（L-LA）/glycolic acid（GA） was developed:Poly（L-lactic acid）（PLLA） and poly（glycolic acid）（PGA） with different molecular weight was first synthesized respectively by binary catalyst（tin chloride/p-toluenesulfonic or tin chloride）;and then poly（L-lactic-co-glycolic acid）（b-PLGA） was produced by melt polymerization of the as-prepared PLLA and PGA.The chain structure and thermal properties of copolymers were studied by Wide-angle X-ray diffraction（WAXD）,nuclear magnetic resonance（NMR）,differential scanning calorimetry（DSC）,and thermogravimenic analysis（TGA）.In comparison with the random PLGA（r-PLGA） synthesized by one-step direct melt polymerization and the m-PLGA,the average L-lactic blocks length(L_LA) in b-PLGA was longer while the average glycolic blocks length(L_GA) in b-PLGA was shorter which further resulted in the improved crystallinity and thermostability.更多还原