【摘要】 直接以廉价的外消旋乳酸(D,L-LA)和亮氨酸(Leu)为原料,以氧化亚锡为催化剂,采用熔融聚合法合成了新型生物材料聚(乳酸-亮氨酸)共聚物,并用FT-IR1、HNMR、DSC、GPC、XRD等进行了系统表征,考察了不同投料比对共聚物的影响。随着投料比中亮氨酸含量n(Leu)的增加,共聚物由一定的结晶态转变为无定形态。所得共聚物的Mw在3 200~6 700之间,Tg都低于均聚物聚外消旋乳酸的Tg,能满足该生物降解材料在药物缓释领域中的应用。更多还原

【Abstract】 Using cheap D,L-lactic acid(D,L-LA) and leucine(Leu) as starting materials,and SnO as the catalyst,a novel biomaterial poly(lactic acid-co-leucine) [P(LA-co-Leu)] was directly synthesized via melt copolycondensation.The copolymer was systematically characterized with FTIR,1HNMR,DSC,XRD and GPC.The effects of different feed molar ratios were discussed.With the increase of molar ratio of Leu in the feed,the crystallinity of copolymer gradually disappeared.Their weight-average molecular weights(Mw) were between 3 200 and 6 700,and the glass-transition temperature(Tg) of copolymers was lower than that of homopolymer poly(D,L-lactic acid)(PDLLA),which could meet the requirement for the application in drug delivery of this biodegradable material.更多还原