| 초록 |
New (α-diimine)nickel(Ⅱ) catalysts based on phenanthrenequinone were prepared and used in ethylene polymerization in the presence of MAO. It has been known that the increase of steric bulkiness of the diimine ligand generally leads to higher branching density. The polyethylenes produced by our catalysts have similar branching density, but the ratio of the branches longer than hexyl was markedly changed as the steric bulkiness varied, and the thermal property of polyethylene was changed significantly. The polyethylene having the melting point above 100 ℃ was obtained despite of high branching density. The precise control of branch distribution is expected to produce polyethylenes with tailored properties. |
