Zr(IV), Ti(IV), and V(III) complexes of some benzimidazole, benzothiazole, and benzoxazole ligands: characterization and catalyst efficiency in ethylene polymerization

Authors : Hamdi Ali ELAGAB, Helmut G ALT

Pages : 667-680

View : 19 | Download : 10

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :Fifteen complexes of 2, 2-bis- insert ignore into journalissuearticles values(benzimidazole, benzothiazole, and benzoxazole); compounds with Zrinsert ignore into journalissuearticles values(IV);, Tiinsert ignore into journalissuearticles values(IV);, and Vinsert ignore into journalissuearticles values(III); metal centers were synthesized, characterized, activated with methyalumoxane insert ignore into journalissuearticles values(MAO);, and then tested for catalytic ethylene polymerization. The activities of the various catalysts were found to be functions of the hetero atoms in the ligand frameworks. The activity of the catalyst system \textbf{6}/MAO was found to be 1372 kg PE/mol cat. h. The polyethylene produced with the catalyst system 6/MAO showed high molecular weights insert ignore into journalissuearticles values(1.84 $\times $ 10$^{6}$ g/mol); and broad molecular weight distributions insert ignore into journalissuearticles values(PD = 11);. This could result from different interactions of the MAO counter ion with the heteroatoms of the catalyst ligand generating different active sites. The effect of the polymerization temperature of the polymers produced with catalyst 6/MAO was also investigated.
Keywords : Bis benzimidazole, bis benzoxazole, bis benzothiazole, complexes, homogeneous ethylene polymerization