SYNTHESIS AND PROPERTIES OF LONG CHAIN BRANCHED POLYETHYLENE WITH BINARY CATALYST SYSTEM

Branched polyethylene were obtained by using homogeneous binary catalyst system composed of two different α-Diimine Nickel catalysts in the presence of MAO. At appropriate polymerization conditions the binary catalyst system shows a good synergic effect, the polymerization activity is higher than any single catalyst. ~(13)C-NMR spectra of resulting PE exhibits methyl, ethyl, butyl, amyl and significant amount of long chain branches (n≥6) in the backbone of polyethylene. The molar ratio of two catalysts and the polymerization temperature(T_p) influence catalytic activity, molecular weight, degree of branching and melting point of the resulting polyethylene greatly.