摘要
聚乙交酯（PGA）是一种简单的聚酯，它具有优异的可生物降解性和生物相容性，其最终降解产物为二氧化碳和水，可通过机体正常的新陈代谢排出体外，是一类较重要的医用高分子材料。
聚乙交酯的经典制备方法主要有两种：直接缩合聚合法和乙交酯开环聚合法。直接缩合聚合法工序短，操作简单，原材料试剂消耗少，但一般只能得到相对分子量在几十至几千的低聚物，产物性能差，易分解，其力学强度远不能满足外科手术缝合线、外科植入材料的使用要求；乙交酯开环聚合法能够合成高分子量的聚乙交酯，且较少有机杂质对产品的干扰等优点。本论文以高纯度的单体乙交酯为原料，采用乙交酯开环聚合的方法合成高分子量的聚乙交酯， 测试了聚合物的特性粘度，并以此参数作为聚合物分子质量的指标 。论文主要考察了催化剂种类及用量、聚合温度、聚合时间、添加剂的种类和用量等因素对聚乙交酯相对分子量的影响。通过聚合反应条件优化，得到了这些影响因素较佳组合。结果表明，聚乙交酯合成的最佳工艺参数为：乙交酯5.0g，加入0.0015g的催化剂 SnCl2·H2O，聚合反应温度为180℃，聚合时间为1.5h；追加聚合温度为160℃，时间为8h。在优化条件下，合成的聚乙交酯的特性粘度为0.435dL/g；在此基础上加入0.0015g的改性剂月桂醇，0.3g的添加剂丙交酯，聚乙交酯的分子量有一定的提高。
关键词：聚乙交酯；开环聚合；乙交酯；生物降解材料
Abstract
Polyglycolide acid is a kind of simple polyester with excellent biodegradability and biocompatibility．Carbon dioxide and water，as its ultimate degraded products can be excreted from the body via metabolism．
There are two means available for the preparation of PGA，namely，contract-synthesis polymerization and ring-opening polymerization．The former is a simple method with the advantages of short procedure，simple operation，and less reagent consumption．Nevertheless，the molecular weight of the PGA has rise value generally within the scope of 10000 or a 1ittle bit more and the degree of polymerization is very low，which enable it far from perfect to satisfy the practical requirements for sewing in surgical operations and transplantation．The glycolide open legally able to synthesize high molecular weight polyethylene cyclic polymers of lactide，and the less the interference of organic impurities in the product．In this thesis，high-purity monomers glycolide has been used as raw materials，glycolide ring-opening polymerization method of synthesis of polyglycolide with high molecular weight． Intrinsic viscosity of the polymers are tested and used as the polymer molecular weight indicators．In the study，the factors of catalyst type and amount of the polymerization temperature，polymerization time，the types of additives and the amount of ester relative molecular weight polyethylene cross have been optimized．The results showed that the optimum parameters are as follows：glycolide 5.0g，SnCl2·H2O 0.0015g，reaction temperature of 180℃，polymerization time 1.5h；an additional polymerization temperature of 160℃，reaction time of 8h．Under the optimized conditions，the intrinsic viscosity of the synthesis of polyglycolide is 0.435dL/g．By adding the modifier lauryl of 0.0015g and additive lactide of 0.3g，the molecular weight of polycolide is improved in some extent．
Key words：polyglycolide；ring-opening polymerization；glycolide；biodegradable materials
