Supporting of nickel(II) acenaphthenediimine with free amino group for ethylene polymerization

Bis (4-(4-amino-3, 5-diethylbenzyl)-2, 6-diethylphenylimino) acenaphthene] dichloronickel (NiLCl₂) was prepared and supported on SiO₂ modified by methyl trichlorsilane(S-1) and on SiO₂-MgCl₂/TiCl₄ (S-2) respectively. Two supported catalysts S-1 and S-2 used as catalysts for ethylene polymerization were studied and the influences of various polymerization conditions, including the polymerization temperature, cocatalysts, Al/Ni molar ratio on the catalytic activity, branching degree and branch length of PE were also investigated. The experimental results show that the supported catalysts exhibit higher catalytic activity for ethylene polymerization, the highest catalytic activity of S-1 using AlEt₂Cl as cocatalyst at 50°C, reaching 5.8×10⁵gPE/molNi··h, and needed lower Al/Ni molar ratio compared to homogeneous analogue.