基于链转移试剂的高端基功能化度及拓扑结构聚合物的RAFT法合成

RAFT was well known for its versatility in terms of monomer choice, polymer architectures and reaction conditions.According to the mechanism of RAFT, the polymerization was initiated by external radicals, which can be created by radical initiator, heat or light, etc.As the result, the polymers obtained by RAFT would contain some polymer chain derived from the initiating radicals, which has initiator moiety at the α-end. It was difficult to synthesize polymers with predetermined α-end structure polymers through RAFT except for the using of same structured R group in RAFT agent with initiator, for example CPDN and AIBN.Thus, it would be valuable to combine the initiator structure with dithiocarbonyl structure together for the benefits of excluding external radicals accompanied with the minimal disturb of the RAFT polymerization.Based such hypothesis, the current proposal focused on the developing of new way to synthesis polymers with high α-end funcitonality by using the newly developed functional RAFT agents, which contain both of the initiating functional groups and dithiocarbonyl groups.The polymerization behavior of some important vinyl monomers, such as styrene, (meth)acrylate, and vinyl acetate, will be investigated by using such initiator functionalized RAFT agent.Through such investigation, the optimized structure of functional RAFT agent and polymerization conditions for synthesizing polymers with precisely designed α-end structure will be established. Furthermore, polymers with complicated topological structures, such as multi-block and cyclic polymers, will be synthesized by further modification of the obtained polymer.

本项目针对目前RAFT聚合中由于使用外加引发剂引发聚合导致聚合物α-端基结构难以进行精密调控的问题，拟通过将具有引发功能的特征结构与具有调控功能的特征结构进行组合，发展一类新型调控试剂，用于调控常见乙烯基单体的自由基聚合，在保留RAFT聚合原有单体适用面广、聚合条件温和、聚合控制性能优异等优势的同时，实现通过RAFT聚合对聚合物α-端基结构的精密调控，并开展基于RAFT聚合的多嵌段、环状等复杂拓扑结构聚合物的简便设计与合成。该聚合体系还可以同时将原有RAFT聚合体系中的三种组分减少为两种组分。因此，该项目的实施不仅具有较高的学术研究意义，也具有一定的潜在工业化应用意义。

RAFT聚合方法是一种非常成熟的可逆钝化自由基聚合（RDRP）方法，然而，由于RAFT聚合中需要使用外加自由基源，因此所制备两个末端功能化度都很高的聚合物存在挑战。本项目针对这一问题，通过将具有引发功能的结构片段与具有调控功能的结构片段的整合，发展了一类具有引发-调控功能的多功能试剂，用于丙烯酸酯、醋酸乙烯酯等单体的活性自由基聚合过程中。通过聚合行为的系统考察，对试剂结构和聚合条件进行了优化，成功制备了具有高端基功能度的聚合物，并进一步用于多嵌段聚合物、高分子量聚丙烯腈、立构规整嵌段共聚物等功能性聚合物的合成中。通过对聚合条件和试剂结构的优化，成功实现了一锅一步法制备嵌段共聚物。项目研究发表SCI研究论文19篇，申请中国发明专利5项，培养博士研究生2名，硕士研究生5名。参加国际和国内学术会议各两次。