聚烯烃型聚氨酯材料的结构设计及耐老化机理研究

Among biomedical polymer materials (especially long-term implanted materials), polyurethane occupies an irreplaceable position in the field of medical treatment because of its unique block structure, good mechanical properties and excellent biocompatibility. Currently, polyurethane materials occur degradation in vivo, such as polyester polyurethane are easy to hydrolysis, polyether polyurethane are easy to oxidation degradation. The in vivo aging of polyurethane has become one of the key problems restricting the further development and application of polyurethane materials. This topic prepares a series of new anti-aging polyurethane material, which is from the point of structure design of materials. It includes the saturated carbon chain of soft segment, combined with the aliphatic ring structure of hard segment. And we will investigate the influences of soft and hard segment structure adjustment on its microstructure and macroscopic properties. Through constructing polyurethane material accurate online continuous aging evaluation method, environmental simulation, online monitoring of polyurethane degradation behavior, this topic can explore the relationship between the structure of polyurethane materials and the aging degradation behavior, and explain the aging degradation mechanism of polyurethane materials clearly. Finally, this topic will induce the influence law between system structure design of polyurethane materials and aging degradation behavior, at the same time put forward the reliable theoretical guidance for the design and research of the aging degradation of polyurethane materials.

在现有的生物医用高分子材料（尤其是长期植入体内的材料）中，聚氨酯材料因其具有独特的多嵌段结构、良好的力学性能和优异的生物相容性,在医疗领域中占据了不可替代的位置。但目前使用的聚氨酯材料在体内均发生了降解现象，如聚酯型聚氨酯易于水解,聚醚聚氨酯易于氧化降解。聚氨酯的体内老化问题已成为限制聚氨酯材料进一步发展和应用的关键问题之一。.本课题拟从材料的结构设计角度出发，将饱和碳链结构引入聚氨酯材料的软段，结合含脂肪环结构的硬段，制备一系列新型抗老化聚氨酯材料。考察材料的软硬段结构调控对其微观结构、宏观性能的影响。通过构建聚氨酯材料精确在线连续老化评价新方法，模拟体内环境，在线监测聚氨酯降解行为，探讨聚氨酯材料结构与老化降解行为之间的关系，并以此来明确解释聚氨酯材料的老化降解机理。归纳聚氨酯材料的结构设计与老化降解行为之间的系统影响规律，同时为耐老化降解型聚氨酯材料的设计和研究提出可靠的理论指导。

聚氨酯材料因其具有独特的多嵌段结构、良好的力学性能和优异的生物相容性, 在生物医疗领域（尤其是体内植入材料领域）应用广泛。但聚氨酯材料在体内的氧化降解及水解问题一直是研究的难点。 .本项目针对目前体内植入聚氨酯材料的老化降解问题，主要围绕着聚烯烃聚氨酯的结构设计和老化机理进行了深入而细致的研究，具体内容主要包括两个方面：.1、利用含饱和碳链结构的软段和含脂肪环结构的硬段设计合成新颖结构的聚烯烃型聚氨酯材料，以此代替传统的含聚酯或聚醚软段的聚氨酯。通过改变聚氨酯材料的软段结构和分子量，选用不同的二异氰酸酯和扩链剂（如含有脂肪环结构的硬段），以及改变软硬段的比例，制备耐老化聚烯烃型聚氨酯材料。深入探讨了聚氨酯的分子链结构、聚集态结构对材料的弹性、模量、强度、硬度、亲疏水性及抗疲劳性等宏观性能的影响。.2、完成了聚氨酯材料耐老化性能测试；完善了聚氨酯材料的制备工艺及配方优化；揭示了聚氨酯材料的老化失效规律，探讨了老化寿命预测的原理和方法、推测老化降解机理，从理论出发，找出了促使聚氨酯材料老化、性能变劣、最终失效的根源所在，从而改善并提高了材料在使用过程中的耐老化性能，验证了耐老化聚氨酯材料在生物医用材料等领域的应用前景，为聚氨酯防老化改性设计及其在体内植入材料领域的应用提供理论支持。