大环聚合物的光化学制备及其性能研究

The design and precision synthesis of polymer topological structures has been always the dominant task in polymer synthetic chemistry, in which macrocyclic polymers, ring chains and polycyclic polymers have attracted a wide range of research interests. These macrocyclic polymers hold important potential for applications in biomedicine, chimeric recognition, self-assembly, high performance polymer materials and other fields. However, few reports can be found in the literature on polycyclic polymers with more than 5 coupling rings or Hopf link structures (i.e. ring-in-ring structure) prepared by polymer chemistry approaches so far. This project is to synthesize complex macrocyclic structures such as 8-word rings, linear polycyclic polymers, combined multicyclic polymers and ring chains based on the photochemistry of hydroxy-cinnamic acid and macrocycle synthesis techniques. This project will solve two scientific problems. One is how to improve the rate of the ring-chain structure, the solution of the problem is conducive to the establishment of a new synthesis methodology of ring-chain structures; the second is how to improve the polymerization degree of the linear polycyclic polymers in the step photo-polymerization of the macrocyclic monomers containing two hydroxy cinnamic acid units. Through the research of this project, it is expected to establish a new synthesis methodology of ring chain structures and to ascertain some mechanical properties of the polycyclic polymers. It is also expected to develop new high-strength and high elasticity polymer materials in this project.

高分子拓扑结构的设计与精密合成一直是高分子合成化学的核心内容，其中大环、环链以及多聚大环聚合物吸引了广泛的研究兴趣，这些大环聚合物在生物医药、嵌合识别、自组装、高性能聚合物材料等领域有重要应用前景。但是迄今为止，通过高分子化学方法制备多于5环的偶联多聚大环结构、以及最基本的Hopf Link结构（即环连环结构）等，仍极少有文献报道。本项目计划基于羟基肉桂酸基团的光化学以及大环合成技术，制备8-字环、线形多聚大环、并合多聚大环、环连环等大环结构。本项目重点解决两个个科学问题，一是如何提高环连环结构的收率问题，该问题的解决有利于确立新的合成环连环结构的方法；二是如何提高含双羟基肉桂酸单元大环的光聚合反应聚合度，得到高聚合度的多聚大环高分子。通过本项目的研究，有望建立环连环结构合成的新方法；制备高聚合度多聚大环聚合物，有利于开发新型高强度高弹性高分子材料。

高分子拓扑结构的设计与精密合成一直是高分子合成化学的核心内容，其中大环、8-字环以及多聚大环聚合物合成及其性质吸引了广泛的研究兴趣。本项目基于偶联化学、羟基肉桂酸基团的光化学以及大环合成技术，制备8-字环、多聚大环等大环结构；研究了Glaser偶联反应、以及其产物共轭二炔结构的聚合反应的特征，并通过这些反应制备多聚大环；对照研究了嵌段共聚物8-字环及其光解聚产物单大环在自组装方面的不同特点；研究了环约束对聚集诱导荧光基团的影响。Glaser偶联反应在成环以及逐步缩合聚合方面效率较高，但需防止共轭二炔聚合副反应。以羟基肉桂酸二聚体为基础可以设计结构可转化的8-字环，对称的嵌段共聚物8-字环与其二聚体解聚形成的单大环对比，具有不同的自组织行为，其中对称PEG-PS-PMA 8-字环可以自组装成螺旋棒，其自组装行为以及螺距/半径比与熵理论预测情况较吻合。嵌合聚集诱导荧光（AIE）基团的多聚大环具有高AIE效率，但发光颜色不随聚集变化。本工作成功制备了系列大环结构，并揭示了大环结构对高分子性能的影响。