【摘要】 取代传统的丙交酯开环共聚法,直接以外消旋乳酸(D,L-LA)为原料,以廉价的氯化亚锡为催化剂,采用熔融聚合法合成胆固醇-聚(D,L-乳酸)共聚物。分别考察不同投料比、预聚时间和熔融共聚时间的影响,并用FT-IR1、HNMR、GPC、DSC等进行了系统表征。当投料比n(胆固醇)∶n(乳酸)=1∶66、预聚4 h、熔融共聚10 h、催化剂用量0.3%时,以85%的产率生成了重均相对分子质量(Mw)达3 600(分散度Mw/Mn=1.24)的共聚物。新方法步骤少、路线简捷,相对分子质量可以达到丙交酯开环共聚法的水平,且成本更加低廉。更多还原

【Abstract】 Using D,L-lactic acid（D,L-LA） as the starting material and cheap SnCl₂ as the catalyst,poly（D,L-lactide-cholesterol） was directly synthesized via melt copolycondensation in place of the traditional ring-opening polymerization of lactide.The copolymer was systematically characterized by FT-IR,（（）¹HNMR）,DSC and GPC.The optimal synthetic conditions,including the feed molar ratio,the prepolymerization time and polymerization time,were discussed.When being catalyzed by 0.3% SnCl₂ at a feed molar ratio of cholesterol to lactic acid equating to 1∶66 and a reaction temperature of 140 ℃,the reaction mixture after prepolymerization for 4 h followed by polymerization for 10 h gave the target product with a yield of 85%.The weight-average molecular weight（Mw） of the copolymer was 3 600,which was higher compared to that achieved by the ring-opening polymerization of lactide.At the same time,the novel direct copolycondensation method was cheaper and more practicable than the traditional method of ring-opening polymerization of lactide.更多还原