Highly efficient FeCl3 doped Mg(OEt)2/TiCl4-based Ziegler–Natta catalysts for ethylene polymerization

Abstract

Seven Mg(OEt)2/FeCl3/SiCl4/TiCl4 type procatalysts supported on Mg(OEt)2/FeCl3 mixtures were prepared in order to unravel effect of Fe doping on the catalytic performance in ethylene polymerization. In polymerization experiments, the catalyst based on a support containing an optimum doping amount of 10 wt.% of FeCl3, i.e. C-F10-Si, exhibited an activity 2.4 times greater than that shown by the reference catalyst, C-M. The MW and bulk density of the produced polymers were increased, while the wax amount decreased using doped catalysts. In the next step, the copolymerization of ethylene with 1-hexene was carried out using C-M as reference and C-Fe10-Si as the most efficient procatalysts. In copolymerization experiments, C-Fe10-Si exhibited much higher activity and comonomer incorporation in comparison with reference catalyst. Finally, to shed light on possible interaction of TiCl4 with doped and undoped catalysts, as well as their efficiency in ethylene polymerization, molecular simulation was performed. Energy results revealed that the doping does not alter significantly the capability of the Ti to insert ethylene monomer.