Catalysts have dominated the molecular weight and polydispersity of resultant polyolefin as well as its microstructure in the polymerization process of olefin

therefore significantly affected their physical and mechanical properties. Nickel catalysts have promoted ethylene reactivity in generating either oligomer or polyethylene; it has been great attractive of observing elastomeric properties of polyethylenes obtained. Therefore extensive investigations would enhance catalytic activities of nickel complex catalysts and result better performances of catalytic systems

achieving novel elastomeric materials of polyethylenes in order to target the further pilot process. Herein the current review collects the new progress of nickel complexes in ethylene polymerization

illustrating correlations or regulations between structures of nickel complexes and their catalytic activities

thermo-stabilities and microstructures of resultant polyethylenes.