Polyethylene with Good Elasticity Synthesized by Anilinotropone Nickel Catalysts

Polyolefin elastomers (POEs) are widely used in automotive, photovoltaic film, and home appliance industries. Compared to the classic copolymerization of ethylene and α-olefin (mainly 1-butene and 1-octene), branched polyethylene (PE) bearing similar elasticity as that of the POE is getting more attention recently. A number of cationic nickel catalyst systems were established, and good to excellent elasticity was achieved. In this work, we developed a series of anilinotropone nickel complexes bearing a hemilabile ethereal group and efficiently polymerized ethylene to produce branched PE. Tensile property study revealed that PE synthesized from the Ni2 (PENi2) catalyst displayed a stress-at-break value of 7.7 MPa and a strain-at-break value of 1870%. Interestingly, the strain recovery (SR) of PENi2 (79%) is higher than that of POEs 8150 (67%) and 7447 (67%). Quantitative ¹³C NMR studies suggest that PENi2 has mainly a methyl branch and a higher total branching density (88/1000) than POEs 8150 (46/1000) and 7447 (76/1000).