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This contribution reports ethylene polymerization behavior of titanium complexes incorporating bis(phenoxyimine) ligands. Six phenoxy-imine Ti(IV) complexes {6-R1-2-[CH=N(2,6-difluoro-3,5-diR2-4-R3Ph)]C6H3O}2TiCl2(1: R1 = H, R2 = H, R3 = H; 2: R1 = H, R2 = H, R3 = 4-vinylphenyl; 3: R1 = CH3, R2 = H, R3 = H; 4: R1 = CH3, R2 = H, R3 = 4-vinylphenyl; 5: R1 = CH3, R2 = F, R3 = H; 6: R1 = CH3, R2 = F, R3 = 4-vinylphenyl) have been synthesized and evaluated for ethylene polymerization using dried MAO(simplified as DMAO) as cocatalyst. An obvious catalytic heterogeneity of Cat 2(Complex 2/DMAO) towards ethylene polymerization was observed, which was illustrated by decreased activity, multimodal molecular weight distribution and partially improved particle morphology comparing with Cat 1. Moreover, Cat 3 exhibits “living” characteristics in the process under certain conditions(25 °C, less than 20 min). Otherwise, the moderate to high ethylene polymerization activity of ca. 105-106 g PE/(mol Ti·h) and high molecular weight(Mw = 105-106) of polyethylene can be obtained by changing the skeleton structure of these complexes.
This contribution reports ethylene polymerization behavior of titanium complexes incorporating bis (phenoxyimine) ligands. Six phenoxy-imine Ti (IV) complexes {6-R1-2- [CH = N (2,6-difluoro-3,5-diR2-4 R2 = H, R3 = H; 2: R1 = H R2 = H R3 = 4-vinylphenyl 3: R1 = CH3 R2 = H R3 = R3 = 4-vinylphenyl; H: 4: R1 = CH3 R2 = H R3 = 4-vinylphenyl 5: R1 = CH3 R2 = F R3 = H 6: R1 = CH3 R2 = F R3 = synthesized and evaluated for ethylene polymerization using dried MAO (simplified as DMAO) as cocatalyst. An obvious catalytic heterogeneity of Cat 2 (Complex 2 / DMAO) towards ethylene polymerization was observed, which was illustrated by decreased activity, multimodal molecular weight distribution and partially improved particle morphology comparing with Cat 1. Moreover, Cat 3 exhibits “living ” characteristics in the process under certain conditions (25 ° C, less than 20 min). Otherwise, the moderate to high ethylene polymerization activity of ca. 105-106 g PE / (mol Ti · h) and high molecular weight (Mw = 105-106) of polyethylene can be obtained by changing the skeleton structure of these complexes.