Enhancing Suppression of Chain Transfer via Catalyst Structural Evolution in Ethylene(Co)Polymerization  

作　　者：Beihang Ding Lihang Jiang Xiaohui Kang Shengyu Dai 

机构地区：[1]Institutes of Physical Science and Information Technology, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Anhui University, Hefei, Anhui, 230601 China [2]College of Pharmacy, Dalian Medical University, Dalian, Liaoning, 116044 China [3]School of Chemical and Environmental Engineering, Anhui Polytechnic University, Wuhu, Anhui, 241000 China

出　　处：《Chinese Journal of Chemistry》2023年第12期1509-1516,共8页中国化学（英文版）

基　　金：supported by Natural Science Foundation of Anhui Province(2108085Y06);Anhui Provincial Key Laboratory Open Project Foundation(LCECSC-01);Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology(BM2012110).

摘　　要：Usually,the aniline-based late-transition-metal catalysts often require bulky steric substituents on both sides of the ortho-aryl position to achieve efficient suppression of chain transfer in ethylene polymerization.In this contribution,we demonstrated thatα-diimine catalysts based on naphthylamine with only one bulky ortho-aryl substituent also demonstrated excellent capabilities to suppress the chain transfer.Firstly,a class ofα-diimine nickel and palladium complexes with only one o-aryl-dibenzhydryl or o-aryl-dibenzosuberyl substituent were synthesized and characterized.Secondly,the as-prepared naphthylamine-based nickel catalysts demonstrated outstanding activities(up to 13.02×106 g·mol–1·h–1)and yielded lightly branched(16-40/1000C)polyethylenes with very high molecular weights(445.8-854.3 kg/mol)in ethylene polymerization.In comparison,the corresponding palladium catalysts showed moderate activities(level of 104-105 g·mol–1·h–1),generating moderately branched(47-78/1000C)polyethylenes with moderate molecular weights(21.6-82.0 kg/mol).Moreover,the palladium catalysts could also copolymerize ethylene and methyl acrylate(MA),albeit in low activities(level of 103 g·mol–1·h–1),providing E-MA copolymers with low to moderate molecular weights(1.4-16.3 kg/mol)and a moderate level of incorporation ratio(2.4-7.4 mol%)and branching density(53-84/1000C).As compared with aniline-based nickel and palladium catalysts,the naphthylamine-based catalysts displayed a superior ability to suppress the chain transfer reactions and could give access to(co)polymers with orders of magnitude higher molecular weight in ethylene(co)polymerization.

关 键 词：α-Dimine catalysts Chain transfer High molecular weight Naphthylamine-based catalysts Ethylene(co)polymerization Copolymers Homogeneouscatalysis Conformation 

分 类 号：O64[理学—物理化学]