A study of ethylene polymerization catalyzed by homogeneous and silsesquioxane supported Titanium(IV) complexes

摘要

The synthesis and characterization of titanium(IV) complexes anchored on poly-hedral oligomeric silsesquioxane (POSS) and cyclohexanediol (CHD) has been investigated and compared with their unsupported analogs. These complexes were employed as catalysts for polymerization of ethylene at high temperatures in combination with organometallic aluminum com-pounds as co-catalysts. The influence of various reaction conditions on polymerization was dis-cussed. The polyethylene obtained was found to be linear and displayed narrow molecular weight distribution with M_w in the range of 600—1000. The polymer was also analyzed with ~1H NMR, ~(13)C NMR and FT-IR spectroscopic method which revealed a chain transfer reaction to aluminum. The unique Iow molecular weight PE formed in this reaction exhibits properties thathave potential industrial applications in surface coating and ink formulations.