Abstract
The article describes ethylene polymerization reactions with transition metal catalysts based on complexes of CoCl2 and FeCl2with an N,N,N-tridentate ligand 2,6-bis[1-(2,6-dimethylphenylimino)ethyl]pyridine.The complexes are converted into polymerization catalysts by reac-ting them either with polymethylalumoxane(MAO)or with a combination of Al(C2H5)2Cl and Mg(C4H9)2 at an[Al]:[Mg]ratio of～3.Both MAO-activated complexes readily polymerize ethylene at 35 ℃ with the formation of linear,low molecular weight polymers with a narrow molecular weight distribution.The same complexes,when activated with the Al(C2H5)2Cl-Mg(C4H9)2 combination,form multi-center catalysts and generate polyethylenes with a broad molecular weight distribution.
万方数据