Comparison of activity of ziegler-natta catalysts prepared by recrystallization and chemical reaction methods towards polymerization of ethylene

Abstract

In the present study, Ziegler-Natta catalysts were prepared on supports that were synthesized via two different methods. The first method (method A) is called the recrystallization method, which employed MgCl2 as a precursor. The second method (method B) is called chemical reaction method, which employed Mg(OEt)2 as a precursor. The catalysts were characterized by XRD, TGA, ESR and nitrogen physisorption. BET specific surface areas of catalyst A and B were 123.1 and 142.2 m2/g, respectively. Polymerization of ethylene was carried out over the catalyst and triethylaluminium. The catalyst prepared by method A exhibited higher activity than that prepared by method B. However, the properties of polymer obtained from both catalysts were similar. The results from XRD and TGA analyses confirmed that Mg(OEt)2 was converted to MgCl2.