6533b7d0fe1ef96bd125b082

RESEARCH PRODUCT

Titanium-magnesium complexes with tetrahydrofuran as precursors of ethylene polymerization catalysts

subject

description

The titanium-magnesium complexes with tetrahydrofuran: [Mg(THF)6][TiCl5(THF)]2 (I); [(THF)4Mg(m-Cl)2TiCl4] (II); and [(THF)3Mg(m- Cl)3Mg(THF)3][TiCl5(THF)] (III), activated with organoaluminium compounds, show low catalytic activities in low-pressure ethylene polymerization, probably because of the high degree of titanium coordinative saturation in these compounds. The Mg:Ti mole ratio raised above 3 by ball-milling I, II, or III with [MgCl2(THF)2], followed by activation with triethylaluminium, has resulted in active catalyst polymerizing ethylene at rates up to 30 kg PE (g Ti h)-1. The catalytic activity varied in the ascending order: III < I < II. The characteristic parameters of the polyethylenes obtained on the catalyst examined were as follows: specific density at 296 К 0.955—0.961 g•cm-3; bulk density124—138 g•dm-3; width of molecular weight distribution 7.38—8.51.