可聚合的氧化还原引发体系

Polymerizable Redox Initiating Systems

胺类具有还原性,可以与多种氧化剂构成氧化还原引发体系,胺类可产生自由基,引发乙烯基单体聚合。若乙烯基单体同时含有胺类基团,则这类自身还原性引发型单体在氧化剂存在的情况下既参与链引发又参与链增长,因此可以形成超支化聚合物。本文首先回顾了胺类氧化还原体系及其引发机理,然后总结自身还原性引发型单体分别与过氧化物、二芳酮、高氧化态过渡金属盐类或超高价态过渡金属络合物等构成的可聚合的氧化还原引发体系。最后,还比较了自身还原性引发型单体的氧化还原引发自由基聚合与自身氧化性引发型单体的自缩合原子转移自由基聚合在支化结构的形成与演化方式上的差别。

Amines, as a class of reducing agents, can yield highly-active radicals via redox initiation with oxidizing agents. Thus, certain amine-containing vinylic monomers, defined as intrinsically reducing inimes,would be involved in both redox initiation and radical propagation steps, finally leading to hyperbranched polymers. In this review,we summarized the amine-involved redox-initiation systems and their mechanisms, subsequently followed by the redox-initiated radical polymerization of intrinsically reducing inimers in the presence of peroxides, diarylketones,high oxidation-state transition metal salts and supernormal valence transition metal complexes. At last,the formation and development of the branching architecture in the redox-initiated radical polymerization of intrinsically reducing inimers were discussed in the context of the self-condensing atom transfer radical polymerization of intrinsically oxidizing inimers.