星形梳状高支化聚酯的合成及形状记忆性能的研究

Biodegradable shape-memory polymers are a class of smart polymer materials, which has been widely used in biomedical and pharmaceutical field. However, the poor relationship between molecular structure and shape-memory effect restrict the range of material's application. In this work, well-defined star-comb polyesters, the (3-armed, 4-armed, 6-armed, multi-armed) star-comb copolymers of poly(trimethylene carbonate)/polylactide with different sequence structures (block, gradient, random), were synthesized by anionic polymerization and living ring-opening polymerization with the star-shaped hydroxylated polybutadiene as macroinitiators; The influences of complex topology structure on the shape-memory property was studied systematically; The shape-memory property was improved and exactly controlled by chemical synthesis and structure design. Herein, a series of biomaterial with novel star-comb architecture was carried out, and the structure-activity relationship was well investigated. Thermoplastic shape-memory polyesters with high-performance and controllable customization would be achieved.

可生物降解形状记忆聚合物是一类新型智能高分子材料，兼具良好的可降解性和形状记忆性能，在生物医用领域具有广阔的应用前景。然而，由于热塑性生物材料的形状记忆性能不高，且影响形状记忆效应的分子内在因素不明确，严重影响了材料的高值化应用。本项目采用活性阴离子聚合及活性开环聚合的方法，设计合成具有新型拓扑结构的聚酯，即以结构丰富可控的星形多羟基液体聚丁二烯为大分子引发剂，高效可控合成一类（三臂、四臂、六臂、多臂）星形梳状高支化结构聚三亚甲基碳酸酯/聚乳酸（嵌段、梯度、无规）共聚物；系统揭示聚合物复杂拓扑结构对形状记忆性能的影响机理；通过化学合成及结构调控，提高和设计聚合物的形状记忆性能。本项目拟创制一类拓扑结构、序列结构精确可控的星形梳状高支化聚酯，探明构效关系，最终实现高性能热塑性形状记忆聚酯材料的可控定制。

可生物降解形状记忆聚合物是一类新型智能高分子材料，兼具良好的可降解性和形状记忆性能，在生物医用领域具有极为广阔的应用前景。然而，由于热塑性生物材料的形状记忆性能不高，且影响形状记忆效应的分子内在因素不明确，极大地限制了材料的高值化应用。本项目基于活性阴离子聚合及活性开环聚合方法，首次以星形多羟基大分子引发剂，创制了一类星形梳状高枝化聚酯，主要创新点包括：（1）发明了高性能星形梳状高枝化聚乳酸系列聚合物，重均分子量高达80万，药物释放和水解速率高于线形聚酯7倍，冲击强度高达891.0 J/m，断裂伸长率高达253.8%；（2）发明了高性能星形梳状高枝化聚己内酯系列聚合物，重均分子量可达70万，载药微球的体外释放率约为60%，是线形聚酯的10倍；（3）发明了高性能无定形星形梳状高枝化聚碳酸酯系列聚合物，重均分子量可达50万，星形梳状嵌段共聚物模量高达1300 MPa、梯度共聚物玻璃化转变温度范围34 ℃、无规共聚物断裂伸长率1797%，是线形聚碳酸酯11倍以上。本项目共计发表研究论文15篇，其中8篇为第一标注；已授权发明专利5项；项目负责人参加学术会议4次，其中邀请报告1次；获科研奖励4项；成果转化2项；培养已毕业研究生5人，其中博士研究生2人。