Preparation And Property Study Of Novel Ni(Ⅱ) Catalysts Containing N, N Ligands For Ethylene Polymerization And Oligomerization

Late transition metal complexes are recently developed high active non-metallocene catalytic system. Especially, the nickel complexes succeeded in both the ethylene oligomerization and polymerization due to their less oxophilic property which are easily to prepare and have high activity.On the base of the investigation about the late transition metal catalysts, we synthesized two novel series of nickel catalysts containing N, N or bis N, N ligands. Our research work was mainly composed of three parts:In the first part, nickel catalysts containing novel N, N ligands were synthesized to oligomerize and polymerize ethylene. The catalytic results demonstrated not only high and long-life oligomerization activity, but also farely polymerization activity. Reaction condition (Al/Ni molar ratio and temperature) greatly influenced the activity and products.In the second part, combination of metallocene metal catalyst and late transition metal complexes were used to in situ polymerize ethylene to prepare LLDPE using MAO as co-catalyst.In the third part, a novel series of nickel complexes containing bis Schiff-base ligands, which were easy to prepare and very stable in the air, were synthesized to oligomerize ethylene and indicate high oligomerization activity.