不同投料比对胆酸改性聚(D,L-乳酸)的影响

The Effects of Different Feed Molar Ratio on Poly(D,L-Lactic Acid) Modified by Cholic Acid

以功能分子胆酸改性聚外消旋乳酸(PDLLA),采用直接熔融聚合法合成了胆酸-聚(D,L-乳酸)共聚物。用特性黏数[η]、FT-IR1、H-NMR、DSC、GPC、XRD等进行系统表征,考察了不同投料比对共聚物的影响。结果发现,随着胆酸和乳酸投料比(物质的量)的减小,共聚物含有的胆酸单元核心逐渐减少。当胆酸和乳酸的投料比为1∶15,有4个胆酸核的共聚物的重均分子量(-Mw)最大,-Mw为12700,分散度-Mw/-Mn为1.68。基本上只含有一个胆酸单元核心的星型高分子,其具有一定的结晶性。

Using functional molecule cholic acid （CA） as starting material, poly（D, L-Lactic acid） （PDLLA） was modified via direct melt eopolycondensation. The copolyrner poly （D, L-lactide-cholate） was systematically characterized with intrinsic viscosity [ η], FT-IR, ^1H-NMR, DSC and GPC. The effects of feed molar ratio were discussed in detail. With the decrease of feed molar ratio of CA to lactic acid （LA）, the number of CA unit as the core embedded in the copolymer reduced. When the feed molar ratio of CA to LA was 1 ： 15, the copolymer embedded 4 CA units, and its weight average molecular weight （M^-w） was maximal （M^-w= 12700, M^-w/M^-n= 1.68）. When just one CA unit core was embedded in the star-shaped copolymer, certain crystallinity was detected.