基于“聚合物积木”方法的功能化树形聚合物精准合成

Because of the specifically topological structures, DendriMac polymers exhibited distinctive properties and became significant research filed in both polymer chemistry and physics. However, some problems such as complicated synthetic routes, inferior control on topology, impossibly precise characterizations and so on, were still existed during the synthesis of DendriMacs. In this application report, a series of “Polymeric Bricks” will be precisely synthesized based on chain-end orthogonal functionalization with living anionic polymerization. Then the shell-functionalized, topological isomer and Janus-functionalized DendriMacs will be precisely constructed with efficient “Hydrosilylation-Ugi” coupling cycles between same or different polymeric bricks. At last, the “Polymeric Bricks” methodoly for precise, efficient and convenient synthesis of DendriMacs will be established. Meanwhile, novel “shell-functional” DendriMacs, such as liquid crystal and fluorescence, can also be prepared via the Click Chemistry between shell-functionalized DendriMacs and corresponding functional moieties. The “Polymeric Bricks” methodoly can be devided into two independent parts of bricks synthesis and bricks coupling. Thus, the whole process of synthesis can be precisely controlled and characterized to ensure the integrity of topological structures in Dendrimacs. Based the above methods, a serial of novel DendriMac modles can be obtained and the study on the correlation of topological structures and properties can be conducted. For the special properties of DendriMacs from their specific topology, the correlation between dendritically structures and novel properties will be clearly stated, which can open up novel prospects for the study on dendritically branched polymers.

树形DendriMac聚合物新颖的拓扑结构赋予其独特的性能，是高分子领域的重要研究内容，而当前DendriMac聚合物合成仍存在实施繁琐、拓扑控制差、精确表征难等问题。项目基于活性阴离子聚合方法结合链端“正交”功能化精准合成类型丰富的基础聚合物积木模块，通过多种相同或不同聚合物积木之间“硅氢加成-Ugi”循环迭代正交反应进行积木搭建，实现“壳层”功能化、拓扑异构体、两面性结构等树形DendriMac聚合物精准构建，建立精准、高效、便捷的树形聚合物积木合成方法，同时通过点击化学反应合成新型壳层功能性（如液晶、荧光等）树形聚合物。整体合成方法分为积木合成以及积木搭建相互独立两部分，基础聚合物积木之间采用高效便捷的“硅氢加成-Ugi”迭代循环偶联反应，实现高代树形结构精准，各级结构均能够精确表征以确保目标树形聚合物具有较好的拓扑结构完整性。通过以上研究，实现基于活性阴离子聚合方法的功能化树形结构聚合物模块化精准合成，建立精准、高效、便捷的树形聚合物积木合成方法，为树形聚合物研究开辟全新的前景，并进一步拓展基于活性阴离子聚合的聚合物精密合成方法学。

随高分子科学发展，对聚合物各级结构的精确调控要求逐渐提高，如何设计精准高效的合成方法、实现高分子各级结构的精确控制，是高分子化学中亟待解决的重要科学问题。将正交点击反应与活性阴离子聚合有机结合，以具有可点击官能团的小分子以及聚合物作为合成基本模块，通过模块化合成实现聚合物结构的精准控制，是高分子精准合成方法进一步发展的全新途径。.通过Ugi-4CR与硅氢加成的正交反应循环，与小分子异构体单元模块结合，合成了分子量和化学组成完全相同、仅连接单元取代基构造不同的同分异构单分散聚合物，建立了Ugi-4CR与硅氢加成正交循环合成单分散聚合物方法，将同分异构体的概念引入到聚合物中。通过调控异构体单元的序列，合成了具有不同构造的连接单元在链中序列精确的同分异构单分散聚合物。通过阴离子聚合合成结构明确的端基硅氢/双炔基功能化聚苯乙烯模块，应用硅氢加成反应合成了支化程度可控的长支链超支化聚合物，支化因子介于0.33~0.52之间。通过阴离子聚合得到结构明确的端基胺基/硅氢功能化的聚苯乙烯模块，应用Ugi-4CR与硅氢加成的正交循环得到第二代树枝状聚合物（DendriMac），数均分子量为50.9 kg/mol，外层臂数8.3符合理论臂数8臂，建立了树枝状聚合物的模块化合成方法。通过阴离子聚合设计结构明确的端基硅氢/双炔基聚丁二烯模块（SiH-PB-yne2）和端基硅氢功能化的聚苯乙烯（PS-SiH）模块，应用聚丁二烯大分子单体进行硅氢加成得到超支化聚丁二烯（HyperPB），支化因子为0.36。PS-SiH与HyperPB进行硅氢加成得到的超支化的苯乙烯-丁二烯-苯乙烯三嵌段聚合物SBS，加氢后得到超支化结构的SEBS，实现了具有超支化结构的热塑性弹性体的合成。