【作者】 丁颂东；

【导师】 王玉忠；

【作者基本信息】 四川大学 ， 材料学， 2006， 博士

【摘要】 脂肪族聚酯具有良好的生物相容性和可生物降解性，在生物医用、药物传输、包装、农业等领域得到了广泛而深入的研究，是一类极具发展前景的高分子材料。 脂肪族聚酯的热稳定性对于其成型加工是至关重要的，尤其对易于发生热降解的脂肪族聚酯如聚对二氧环己酮（PPDO）等更是如此。PPDO具有良好的生物相容性、生物降解性和优异的力学性能，但其热稳定性却较差。由于对二氧环己酮（PDO）单体的聚合上限温度仅265℃，明显低于L-丙交酯、ε-己内酯等内酯。用金属有机化合物如SnOct₂、Al（OiPr）₃、ZnEt₂等作催化剂，通过PDO单体开环聚合得到的PPDO均聚物，在加工过程中极易发生热降解，分子量及熔体粘度均会显著降低，力学性能会受到严重影响。因此，提高PPDO的热稳定性是改善PPDO加工性能，以及PPDO能否得到广泛应用的关键问题之一。 不同脂肪族聚酯的组成和结构，赋予了各自不同的性能和用途，其中材料的降解性是影响其用途的重要因素之一。例如，聚己内酯（PCL）降解速率较慢，是植入材料较理想的选择，但用作缓释药物载体，目前只适用于长效药物，对于短效药物，却因其降解速率太慢，不易在体内吸收，而受到限制，作为环境材料使用，它的降解速率还不能适应某些特殊用途。如果脂肪族聚酯的降解性能能得到有效控制，表现出不同的降解行为，则可使这类高分子材料具有更加广泛的用途。 本论文着重于如下两个方面进行研究：一是PPDO的热降解与稳定；二是PCL的催化降解。 使用SnOct₂作引发剂，通过PDO的开环聚合合成了PPDO，并对其进行了更多还原

【Abstract】 Aliphatic polyesters, one of most promising biodegradable polymers, have been studied extensively and intensively due to their good biocompatibility and biodegradability, and they have found their applications in the fields of biomedical materials, drug delivery systems, packaging materials, agriculture, and so on.The thermal stability of aliphatic polyesters is very important to their processing and forming, specially for the aliphatic polyesters liable to thermal degradation such as poly（p-dioxanone） （PPDO）. PPDO has good biocompatibility, biodegradability and mechanical properties, but it has a poor thermal stability. The ceiling temperature of polymerization of （p-dioxanone） （PDO） is only 265 ℃, much lower than that of L-lactide or ε-caprolactone. PPDO is usually synthesized through a ring-opening polymerization of PDO in the presence of organometallic catalyst such as SnOct₂, Al（OiPr）₃, and ZnEt₂. Due to the poor thermal stability, the molecular weight and melt viscosity of PPDO significantly decrease during processing, causing the deterioration of its mechanical properties. Therefore, how to enhance the thermal stability of PPDO is very important to the processing and extensive applications of PPDO.The properties and applications of aliphatic polyesters depended on their compositions and structures. The degradability is one of the significant factors affecting their applications. For example, poly（ε-caprolactone） （PCL） is suitable for implantation material, and not suitable for a carrier for fugitive drug due to its slow更多还原