Catalytic behaviors of SiO2-supported various aluminoxanes as coactivator in MgCl2/DEP/TiCl4-TEA catalysts for propylene polymerization

摘要

The study showed that the use of silica-supported aluminoxanes as coactivator can alter the catalytic behaviors of MgCl2/diethylphthalate (DEP)/TiCl4 catalyst with triethylaluminum (TEA) as an activator for propylene polymerization. It was found that the catalytic activities were ranged between 380 and 760 kg PP/mol.Ti.h within the order of dMMAO/SiO2 > MAO/SiO2 > MMAO/SiO2 > dMMAO > no coactivator > SiO2. The TGA analysis revealed that the strong interaction between aluminoxane compounds and support apparently resulted in a decreased catalytic activity. Based on the polymer microstructure, it indicated that an enhanced activity can be attributed to the increase in active site concentration.