中文摘要：

采用直接熔融共缩聚方法成功地制备了L-酸酸/β-丙氨酸共聚物，用红外光谱、核磁共振、凝胶色谱和DSC等方法对共聚物结构进行了表征；考察了催化剂用量、投料比、聚合反应时间和反应温度等聚合条件对产物分子量及其结晶性能的影响．实验结果表明，采用质量分数为1．5％的亚锡复合催化剂在180℃下真空反应15h为最佳聚合条件，所得到的产物具有相对最大的分子量；随着β-丙氨酸投料比增加，相应共聚物的分子量明显下降。所得到的L-乳酸/β-丙氨酸共聚物具有良好的降解性能，聚合时间和β-丙氨酸含量对材料的结晶性能和降解性能均有较大的影响。

英文摘要：

Poly（L-lactic acid-co-β-alanine） , a novel biodegradable polyesteramide, was produced by direct melting copolymerization with stannous chloride and p-toluenesulfonic acid as the catalyst, and characterized via FTIR, ^1H NMR, ^13C NMR, GPC and DSC. To optimize the copolymerization conditions, the content of catalyst, copolymerization temperature and time, as well as the feed ratio, were investigated. The results show the copolymers with a high molecular weight could be obtained from the copolymerization process conducted at 180℃ for 15 h with 1.5% of stannous complex catalyst under vacuum. The hydrolytic degradation test in PBS （pH = 7.2, 37℃） indicates poly （L-lactic acid-co-β-alanine） has an excellent degradability, which could provide a potential application in the biomedical field as a drug control released material.