Study on ethylene/1-hexene copolymerization catalyzed by α-diimine nickel catalysts with different ligands--Dedicated to Professor Xiuwen Han on the occasion of her 80th birthday  

作　　者：Yusheng Xing Haojie Yu Li Wang Nan Wang Lei Zhu Ruixue Liang Md Alim Uddin 

机构地区：[1]State Key Laboratory of Chemical Engineering,College of Chemical and Biological Engineering,Zhejiang University,Hangzhou,310027,China

出　　处：《Magnetic Resonance Letters》2021年第2期131-141,共11页磁共振快报（英文）

基　　金：Financial support from the National Key Research and Development Program(2016YFB0302403)is gratefully acknowledged.

摘　　要：The structure of polyolefin has an important influence on its performance and application.Ethylene/1-hexene copolymerization is one of the important ways to control the structure of the polyolefin.However,research on the ethylene/1-hexene copolymerization catalyzed by nickel complexes with different steric ligands remains to be refined.Here,three α-dimine nickel catalysts are used to study the ligand effect on catalytic performance in the ethylene/1-hexene copolymerization.Reaction activity,molecular weight,phase-transition temperature and branching density of the resultant copolymer are measured to evaluate the catalytic performance.The results indicate that the steric ligands could exert great effect on the copolymerization.As for the chemical valence of Ni species,detailed EPR demonstrate that the presence of excess xo-catalyst can reduce Ni(Ⅱ)to the lower valence and affect the catalytic performance.

关 键 词：α-diimine nickel catalysts COPOLYMERIZATION Microstructure EPR spectroscopy 

分 类 号：O64[理学—物理化学]