| 초록 |
Late transition metal olefin polymerization catalysts have received much attention recently. Fe(II) and Co(II) catalysts are robust and extremely active for polymerization of ethylene to linear, high-density polyethylene. On the contrary, Ni(II) and Pd(II) catalysts could convert ethylene directly to highly branched polyethylene without the addition of expensive α-olefins. In the present study we have synthesized bimetallic-iron and nickel based-trinuclear catalysts. Binuclear 2,6-Bis(imino) pyridyliron complex and mononuclear α-diimine nickel complex, based on same trinuclear ligand, were prepared to compare with iron and nickel based bimetallic trinuclear complex. Polymerization with these catalysts has been explored under a variety of reaction condition. These catalysts showed high activity and long life time in ethylene polymerizations. The effects of the ligand structure of newly synthesized catalyst on the microstructure of polymer formed were analyzed using DSC, NMR, and GPC. |
