Ethylene/alpha-olefin copolymerization using mixed oxides-supported methylalminoxane with zirconocene catalyst

Abstract

In this research, due to the commercial interest of using metallocene catalysts for olefin polymerization, it has led to extensive efforts to utilize metallocene catalysts efficiently. However, it was found that homogeneous metallocene catalysts have two major disadvantages (i) the lack of morphology control and (ii) reactor fouling. Therefore, binding these metallocene catalysts onto inorganic supports as supported metallocene catalysts can overcome those drawbacks. Copolymerization of ethylene with higher 1-olefins is a commercial importance for production of elastomer and linear low-density polyethylene (LLDPE). Metallocene catalysts have been studied for such a purpose because an excellence of comonomer insertion can be achieved. However, using a metallocene catalyst can result in a narrow molar mass distribution (MMD) with poor processibility. Thus, broader MMD of polymers is preferred in terms of processability. This could be achieved using mixed oxide supports to generate different natures of active sites. In this present study, mixed supports between Titanium oxide and Silicon oxide with various ratios of Titanium oxide : Silicon oxide were used as supported methylaluminoxane (MAO) cocatalyst for ethylene/1-octene copolymerization using zirconocene catalyst. The polymers obtained with various ratios of mixed supports were further characterized. It was found that using Titanium oxide : Silicon oxide (20:80 by weight) could result in an increased activity compared to Silicon oxide or even Titanium oxide itself. Effect of the Titanium oxide : Silicon oxide ratios of mixed supports on the polymer properties can see in this research.