星形聚乙烯的合成方法研究进展

Progress on the Synthesis of Star Polyethylenes

星形聚乙烯是一类具有特殊拓扑结构的聚乙烯,性能独特,可通过调控臂数和臂长来调控性能。这些调控方法主要取决于星形聚乙烯的合成方法。因此,研究开发星形聚乙烯的高效合成方法非常重要。文中总结了星形聚乙烯的合成方法,主要包括星形聚丁二烯还原法、乙烯配位活性聚合法和端基官能化聚乙烯法。其中,乙烯配位活性聚合法是合成星形聚乙烯最直接的方法(“先核后臂”法和“先臂后核”法),其原理是基于对α-二亚胺钯配合物催化的乙烯活性聚合进行结构设计,得到臂长和臂数可控的星形聚乙烯。

Star polyethylene exhibits many unique properties due to its special topology.The chemical structure of star polyethylene can also be regulated by changing the number and length of arm.It is important to study the synthesis methods of star polyethylene.Herein,the synthesis methods of star polyethylene were summarized,including the hydrogenation of star 1,4-polybutadiene,living coordination polymerization of ethylene,and sol-gel of chain-end functionalized polyethylene.The synthesis of star polyethylene by living coordination polymerization of ethylene is the most direct method,including the“core-first”method and“arm-first”method.The length and number of arm in the star polyethylene can be controlled based on the living coordination polymerization of ethylene catalyzed by palladium complexes bearingα-diimine ligand.