马来酸酐改性端羟基乳酸预聚体的合成及性能研究

采用聚乙二醇（PEG）与乳酸反应，合成了端羟基乳酸预聚体（PLEG）。然后将PLEG与马来酸酐进行直接熔融缩聚得到改性聚乳酸（MPLA）。采用正交分析法探讨了原料比、反应温度、反应时间等工艺条件对MPLA相对分子质量的影响，并研究了MPLA的亲水性能、力学性能和在体外模拟生物环境中的降解特性。结果表明：马来酸酐与PLEG的质量比为1:15，在130 ℃反应15 h，MPLA的黏均相对分子质量最大为61564。相较于PLEG，MPLA的拉伸强度、弹性模量和断裂伸长率明显提高，亲水性得到改善。MPLA在体外模拟生物环境中的降解性能较好，其降解速率与马来酸酐含量有关。

Study on Synthesis and Properties of Maleic Anhydride Modified Lactic Acid Prepolymer

Hydroxyl terminated lactic acid prepolymer （PLEG） was synthesized from poly ethylene glycol (PEG) and lactic acid, which was further condensed with maletic anhydride (MA) forming MPLA. The effect of reaction conditions (composition, temperature, reaction time, etc.) on the molecular weight (MW) of the product was studied via orthogonal design experiments. The maximum MW about 60000 was obtained at a weight ratio of MA/PLEG of 1/15, reacted at 130 C for 15 h. The mechanical properties, hydrophilicity, and in vitro degradation behavior of MPLA were studied. Modified with MA, MPLA exhibited better tensile strength, modulus, elongation at break, and hydrophilicity than PLEG. In addition, MPLA showed good in vitro degradation behavior, with the degradation rate related to the content of maletic anhydride.