聚乙烯亚胺是一种典型的阳离子聚合物，在造纸、水处理、非病毒基因载体等领域的应用意义重大。线性聚乙烯亚胺通常由2-恶唑啉或N-烷基取代氮杂环丙烷开环聚合反应合成，但这些合成方法局限性较大，例如反应条件苛刻，微观结构难控制，氮原子取代基难以脱除，难以高效合成共聚杂化材料等。本项目将利用N-磺酰基取代氮杂环丙烷的“活性”开环聚合反应，拟通过设计合成新型单体（氮原子取代基易脱除的或功能化的单体）、新型引发剂（功能化的或（杂）多官能团化的引发剂），发展新聚合体系（催化新型引发剂引发聚合及发展“催化剂转换”策略），实现功能化的或复杂拓扑结构的聚乙烯亚胺及聚乙烯亚胺杂化共聚材料的高效、精密合成。本项目的实施将为聚乙烯亚胺基高分子的精密合成提供有力的保证，将进一步促进聚乙烯亚胺基高分子材料更广泛的应用。

Poly(ethylene imine) (PEI), one of the most prominent examples of cationic polymers which contains a lot of nitrogen atoms in the chain, is highly desirable attributing to the great significance for applications in the pulp and paper industry, the waste water treatment, and the nonviral gene-transfer agents. The linear PEIs were usually synthesized via ring-opening polymerization of 2-oxazolines or N-alkyl aziridines, but there existing many drawbacks, such as harsh reaction conditions needed, difficulty of controlling microstructure of obtained polymers, difficulty of removing N-protecting groups, and inefficiency of synthesizing PEI hybrids. Herein, developing new strategies for the precise preparing functionalized PEIs and PEI-based hybrids with novel architectures, via "living" ring-opening polymerization of aziridines, will be studied. Efforts will be made in the utilization of novel functionalized aziridine monomers or monomers with easily removable N-protecting group, design and synthesizing functionalized initiators or initiators with multi-initiating sites, and development of new catalytic systems for new initiators or “catalyst switch” strategy. Implementation of this project will enhance the availability of precisely synthesized PEIs, and further benefit the applications of PEIs and PEI hybrids in various areas.