摘要
由聚(琥珀酰亚胺-乳酸)的碱溶液水解反应制备了含有亲水性羧基的聚(天冬氨酸-co-乳酸)(PAL)。用IR、NMR、DSC、元素分析等方法表征了PAL的组成和结构。结果表明,PAL中的聚乳酸链段为间同立构或无规立构,由此推断丙交酯在开环聚合反应时发生了酯交换或链转移反应,导致聚乳酸链段产生消旋现象;聚合反应机理是羟基引发的聚合,获得了无定型态聚合物PAL。由于共聚反应中丙交酯熔体的蒸发损耗,合成的PAL中聚天冬氨酸的含量高于理论值。
poly（aspartic acid-co-lactic acid） （PAL） with hydrophilic reactive amido and carboxyl was prepared by alkali hydrolysis of poly（suecinimide-lactic acid）. The composing and structure of PAL were characterized by IR, NMR, DSC and elemental analysis. The results of characterization show that PAL is amorphous and poly（lactic acid） units in it is not stereospecific. Therefore, it can be concluded that the recemization occurs in the ring- opening of L- lactide by the transesterifications and chain transfer, and the reactive mechanism is that the polymerization is initiated by trace hydroxyl in the system. The content of poly（aspartic acid） units in PAL is more than that of aspartic acid in the two monomers due to the evaporation loss of L-lactide in the period of copolymerization.
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
2009年第3期35-38,共4页
Polymer Materials Science & Engineering
