Preparation of (n-BuCp)(2)ZrCl2 Catalyst Supported on SiO2/MgCl2 Binary Support and its Ethylene-1-hexene Copolymerization

In this study, (n-BuCp)(2)ZrCl2, was supported on SiO2/MgCl2 binary support. Before supporting the catalyst, the SiO2/MgCl2 binary support was surface treated with three different alkyl aluminum compound, namely trimethylaluminum, triethylaluminum, and ethylaluminum sesquichloride. The synthesized surface-treated SiO2/MgCl2 supported metallocene catalysts were used for the copolymerization of ethylene and 1-hexene. Their catalytic properties and performances were analyzed through BET, XPS analysis, ICP-AES analysis, and FE-SEM. While the resulting copolymers were analyzed through DSC analysis, GPC analysis, 13C-NMR analysis, and FE-SEM. The analysis of synthesized surface-treated SiO2/MgCl2 supported metallocene catalysts showed that the Zr content of these catalysts is relatively lower compared to that of the catalyst supported on SiO2. This could be attributed to the reduction in the surface area of SiO2 due to the presence of recrystallized MgCl2 and alkyl aluminum. Furthermore, they exhibited a better copolymerization activity compared to that of SiO2 supported catalyst, particularly the EASC-surface treated binary support, which has the highest activity of 1.9 kg PE/(mmol-Zr*hr) because EASC acts as a strong Lewis acid. It could also be observed that the larger the ligand of alkyl aluminum used, the rougher the particle surface of the resulting polymer.