【作者】 李永刚；

【导师】 潘君； 王远亮；

【作者基本信息】 重庆大学 ， 药物化学， 2006， 硕士

【摘要】 聚乳酸具有优良的生物相容性和可生物降解性。聚乳酸及其共聚物在生物材料领域,特别是作为组织工程支架材料、药物释放材料和骨折内固定件的应用日益广泛,受到人们的重视。作为生物医用材料的聚乳酸及其共聚物合成的中间体——丙交酯,也因此受到重视。长期以来,丙交酯的成本一直是制约聚乳酸大规模生产及推广应用的最重要的因素之一。要解决规模化聚乳酸的合成问题,重要的一条途径是先解决丙交酯的规模化合成问题。由于目前国内还没有规模化合成丙交酯的技术及厂家,本文在自主研发的中试设备上进行了丙交酯的合成工艺研究,探索规模化合成的工艺条件。1对影响丙交酯生产的工艺条件:脱水温度、脱水时间、蒸馏温度进行了单因素考察试验,结果分别表明脱结合水温度在120-125℃,脱水时间4h,蒸馏温度为200-210℃时,丙交酯的产量最高、酸含量最低。2通过多种催化剂的比较,以催化效果和催化剂价格为指标筛选得到了催化效果好且价格低廉的催化剂——乳酸锌,讨论了催化剂对于合成丙交酯工艺的影响。研究表明规模化合成丙交酯的催化剂用量在2%能提高相同条件下丙交酯的产量和纯度。3优化了规模化生产丙交酯的工艺:以丙交酯的产量和酸含量为考察指标,以脱水温度、脱水时间、蒸馏温度为因素,设计了正交实验,得到最优工艺条件。优化结果表明:脱结合水时间及蒸馏温度对试验的影响较大,从节约能耗和提高产量考虑,脱结合水温度在120-125℃,脱水时间4h,蒸馏温度为210-220℃为最优生产条件。采用提勒管测定了精制的丙交酯的熔点,用红外吸收光谱、示差扫描量热分析、X射线衍射分析对合成的丙交酯进行了表征。结果表明重结晶三次后丙交酯纯度达到聚合要求,熔点为126.3℃。4为改善聚乳酸的应用性能,将丙交酯的聚合物——聚乳酸用氨基化聚乙二醇改性,以增加聚乳酸的亲水性和抗非特异性蛋白吸附性能,对改性材料进行了提纯,进而通过红外光谱、核磁共振对改性材料的结构进行了表征,研究表明氨基化聚乙二醇成功接枝到聚乳酸材料上,接枝率达到1.15%,这种材料可能成为药物控制释放的一种优良的载体材料。更多还原

【Abstract】 Polylactide (PLA) is one of the few polymer materials with good biocompatibility and biodegradability. As biomaterial, the applications of PLA and its copolymers are more and more widely, especially in tissue engineering scaffold, carrier for pharmaceutical release and internal fixation of bone fracture. Lactide, an intermediate of PLA and its copolymer, of course are catching more attention. The costs of lactide are one of the most important factors that hamper the PLA from large scale production and widely use for a long time. To solve these problems, exploring the technique of large scale production of lactide is necessary for there is no technique in China to produce lactide in large scale now. In this paper, we tried to figure out a set of synthetic condition for large scale production of lactide using the equipments designed by our lab.1 The synthetic condition of large scale production of lactide was studied with single factor optimizing method according to the yield and purity of lactide. Three factors we have chosen: dehydration temperature and time, and distill temperature. The optimizing results was dehydration temperature 120-125℃, dehydration time 4 hours, distill temperature 200-210℃.2 A catalyst with high-power and low-cost—zinc lactate was selected in our experiments from several kinds of catalysts. And the optimum proportion is 2% which can increase the yield and purity of lactide under the same condition.3 Optimizing the synthetic condition of large scale production of lactide: judged by the yield and lactic acid content of lactide, an orthogonal experiment with three factors which were dehydration temperature, dehydration time and distill temperature were designed. The results indicated that the dehydration time and distill temperature were the main factors affecting the yield and acid content of lactide. From the points of energy consumption and lactide yield, the best synthetic condition in large scale was as follows: dehydration temperature is 120-125℃, dehydration time is 4 hours, distill temperature is 210-220℃. Then, the melting point was tested by Thiele tube and lactide were characterized by IR spectrum, TG and DSC, XRD spectrum respectively. The result indicated the purity of lactide which had been recrystallized thrice can meet the requirement of synthesizing high molecular PLA and its melting point is 126.3℃.4 In order to improve the characters of PLA in application, it was modified with polypropylene glycol, then purified and characterized by IR and 1H-NMR spectrum.更多还原