Titanium and vanadium based non-metallocene catalysts for olefin polymerization

Titanium complexes with chelating 2,2'-thiobis(4-methyl-6-R-phenoxy) ligand (R= CH3, i-C3H7, t-C4H9, Si(i-C3H7)3) ligands in combination with methylalumoxane, methylisobutylalumoxane or triisobutyl-aluminum/(C6H5)3CB(C6F5)4 as cocatalyst were highly active toward olefin, giving polymers with high molecular weight. Especially, titanium complexes having the most bulky substituent of Si(i-C3H7)3 showed the highest activity of ethylene polymerization. Vanadyl complexes with 2,2'-thiobis(4-methyl-6-tert-butylphenoxy) ligand prepared by the reaction with VO(OC4H9)3 were also highly active to propylene, giving isotactic polypropylene with the melting temperature of 138°C.