| 초록 |
New α-diimine ligand, 9, 10-bis(2, 6-dimethylphenylimino)-9, 10-dihydrophenanthrene was prepared by condensation of phenanthrenequinone with 2, 6-dimethylaniline catalyzed by TiCl4/DABCO. The coordination reaction of that ligand with (DME)NiBr2 produced the (α-diimine)nickel catalyst that was found to catalyze ethylene polymerization with comparable activities to typical Brookhart’s α-diimine nickel catalysts in the presence of MAO. The catalyst produced polyethylenes with high molecular weights at low polymerization temperature, e.g., 1.26-2.14×106 g/mol at -15 oC. The structure of catalyst and reaction conditions, e.g., reaction temperature and concentration of activator (MAO), had significant influences on the polymerization activities, molecular weights and microstructures of the resulting polyethylenes. |
