Propylene polymerization behavior of fluorinated bis(phenoxy-imine) Ti complexes with an MgCl2-based compound(MgCl2-supported Ti-based catalysts)

摘要

Fluorinated bis(phenoxy-imine)Ti complexes 1-3 combined with MgCl2/i-BunAl(OR)(3-n) (MgCl2-supported catalysts) were able to polymerize propylene in a living fashion at room temperature to provide slightly,to highly syndiotactic poly(propylenes) (PPs) with extremely narrow distributions of molecular weight. These represent the first examples of MAO- and borate-free group 4 metal-based living catalysts. The supported complexes 2 and 3 formed PPs with higher syndiotacticity and T-m's than the corresponding homogeneous MAO-activation systems (e.g., 3: rr 97%, T-m 155 degrees C; MAO activation: rr 93 %, T-m 152 degrees C). The measured T-m of 155 degrees C represents the highest known T-m for syndiotactic PPs synthesized at room temperature.