Copolymerization of ethylene with polar monomer by α - diimine nickel complex

Abstract

Copolymerization of ethylene and ethyl acrylate was carried out by α-diimine nickel catalyst [ArN=CH-CH=NAr]NiBr2 (Ar = 2,6-C6H3(CH3)2) in the presence of methylaluminoxane (MAO). The effects of experimental conditions in which mole ratio of Al/Ni, concentration of polar monomer, polymerization temperature, ethylene pressure and polymerization time varied on ethylene-ethyl acrylate copolymerization were investigated. The structures of the obtained copolymers were characterized by high-temperature NMR and FT-IR. It was found that Al/Ni mole ratio was 1000, the concentration of ethyl acrylate was 10 mmol/L, the polymerization temperature was 30 °C, the ethylene pressure was 10 atm, the polymerization time was 4 h, the molecular weight of the polymer and the incorporation of ethyl acrylate in the copolymer reached the good result.