Polymerization of ethylene using a nickel α-diimine complex covalently supported SiO2-MgCl2 bisupport

Bisupported catalyst for ethylene polymerization was prepared by mixing alcohol solution of MgCl2 with pretreated SiO2 in heptane, the prepared bisupport was modified by treatment with alkyl aluminum compounds, and further treatment with bis(4-(4-amine-3,5-diisopropylbenzyl)-2,6- diisopropylphenylimino) acenaph-thene NiBr2 (abbreviaed as NiLBr 2) solution. The most significant feature of the supported catalyst is that it polymerizes ethylene with high activities in the presence of inexpensive general alkylaluminum compounds. According to the results of high temperature GPC, the number-average molecular weights of the polymers ranged from 2.15×105 to 9.27×105 and the polydispersities ranged from 3.12 to 4.23. By modulating the polymerization temperatures, the products of different and good morphologies were obtained. The resultant PE was confirmed by 13C NMR to contain significant amounts of not only methyl but also ethyl, propyl, butyl,amyl, and long branches (longer than six carbons).