%0 Journal Article
%T Synthesis of Branched Polyethylene via Bulky <i>&#945;</i>-Diimine Nickel(II)-Catalyzed Ethylene Chain-Walking Polymerization
%A Zhengquan Dong
%A Pei Li
%A Guoyong Xu
%A Fuzhou Wang
%J Open Journal of Organic Polymer Materials
%P 1-12
%@ 2164-5752
%D 2024
%I Scientific Research Publishing
%R 10.4236/ojopm.2024.131001
%X The catalysis of olefin polymerization through the chain-walking process is a subject of great interest. In this contribution, the successful synthesis of a Brookhart-type unsymmetrical <i>&#945;-</i>diimine nickel catalyst <b>Ni</b>, which contains both dibenzhydryl and phenyl groups, was determined by X-ray crystallography. The compound has a pseudo-tetrahedral geometry at the Ni center, showing pseudo-C2-symmetry. Upon activation with modified methylaluminoxane (MMAO), <b>Ni1</b> exhibits high catalytic activity up to 1.02 &#215; 10<sup>7</sup> g PE (mol Ni h)<sup>&#8722;1</sup> toward ethylene polymerization, enabling the synthesis of high molecular weight branched polyethylene. The molecular weights and branching densities could be tuned over a very wide range. The polymerization results indicated the possibility of precise microstructure control, depending on the polymerization temperature. The branching densities were decreased with increasing the polymerization temperature.
%K Ethylene Polymerization
%K <i>&#945
%K </i>-Diimine Ni(II) Complex
%K Chain-Walking Polymerization
%K Branched Polyethylene
%U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=133891