Recent Advances in the Copolymerization of Ethylene with Polar Comonomers by Nickel Catalysts

Abstract

The less-expensive and earth-abundant nickel catalyst is highly promising in the copolymerization of ethylene with polar monomers and has thus attracted increasing attention in both industry and academia. Herein, we have summarized the recent advancements made in the state-of-the-art nickel catalysts with different types of ligands for ethylene copolymerization and how these modifications influence the catalyst performance, as well as new polymerization modulation strategies. With regard to α-diimine, salicylaldimine/ketoiminato, phosphino-phenolate, phosphine-sulfonate, bisphospnine monoxide, N-heterocyclic carbene and other unclassified chelates, the properties of each catalyst and fine modulation of key copolymerization parameters (activity, molecular weight, comonomer incorporation rate, etc.) are revealed in detail. Despite significant achievements, many opportunities and possibilities are yet to be fully addressed, and a brief outlook on the future development and long-standing challenges is provided.

Advance on nickel‐ and palladium‐catalyzed insertion copolymerization of ethylene and acrylate monomers

“…Due to the low oxophilicity of nickel metal center, there has been increasing research interest in exploring the copolymerization of olefins with polar monomers using nickel catalytic systems. Some chelate ligands including [N,N], [N,O], [P,O], and [P,N] types have been designed for ligating nickel metal 37,48 …”

“…[27][28][29][30][31][32][33][34][35] Although recent reviews have summarized Ni/Pdcatalyzed insertion copolymerizations of ethylene and polar comonomers in viewpoint of catalyst, copolymerization mechanism and copolymer microstructure are rarely discussed. 36,37 In this review, we summarize advance on nickel-and palladiumcatalyzed insertion copolymerization of ethylene and acrylate comonomers in viewpoint of catalyst and copolymer structure and property. Firstly, mechanistic study of nickel-and palladium-catalyzed coordination copolymerization of ethylene and acrylate comonomers is described.…”

Efficient Copolymerization of Ethylene with Polar Divinyl Monomer by Phosphino‐Phenolate Nickel Catalyst†

“…The introduction of polar functional groups can efficiently improve important material properties of traditional polyolefins, such as printability, dyeability, adhesion, compatibility with other polymers, and so on. [ 3‐7 ] In recent decades, the development of novel catalysts for olefin coordination polymerization, especially late‐ transition metal catalysts represented by nickel‐based and palladium‐based catalysts, has achieved great success in generating various functionalized polyolefins via direct coordination‐insertion copolymerization of olefins with various polar monomers. [ 4,6‐22 ] Focusing on optimizing the structural design of the catalysts, a series of late‐transition metal catalysts by adjusting the steric hindrance effect and electronic effect of ligands have been employed to copolymerize ethylene with a library of polar monomers, such as acrylic acid, [ 23 ] acrylates, [ 7,12,24 ] vinyl fluoride, [ 25 ] acrylonitrile, [ 26 ] vinyl ether, [ 27 ] vinyl trialkoxysilanes, [ 28 ‐ 29 ] and the like.…”

Trapping the Short‐Chain Odd Carbon Number Olefins Using Nickel(II)‐Catalyzed Tandem Ethylene Oligomerization and Friedel‐Crafts Alkylation of Toluene

“…[ 2‐3 ] Recently, nickel complexes have been widely used in processes of chain‐walking ethylene polymerization [ 4‐11 ] and copolymerization of ethylene with polar monomers. [ 4,12‐18 ] However, the interest in the development of new nickel‐based catalytic systems for ethylene oligomerization is still high, [ 6,19‐20 ] due to their high activity and selectivity toward butenes [ 21‐24 ] and, in some cases, toward hexenes and higher olefins. [ 25 ] Moreover, such systems are also able to catalyze Friedel‐ Crafts alkylation of toluene with low molecular weight [ 26‐29 ] or high molecular weight [ 30‐32 ] ethylene oligomers.…”