Novel SiO₂‐Supported Chromium Oxide(Cr)/Vanadium Oxide(V) Bimetallic Catalysts for Production of Bimodal Polyethylene

Abstract

Novel SiO 2 ‐supported Cr–V bimetallic oxides catalysts, which were capable of one‐pot synthesizing polyethylene with bimodal molecular weight distribution, had been successfully developed. These catalysts were prepared with a simple introduction of vanadium oxide onto the traditional Phillips CrO x /SiO 2 catalyst. The polymerization activity over the Cr–V bimetallic catalysts was significantly improved compared with the V‐free Phillips CrO x /SiO 2 catalyst. Moreover, the bimodal ethylene/1‐hexene copolymer prepared by the novel catalyst showed a better short chain branch distribution with more 1‐hexene comonomer inserted into the PE chains with high molecular weight, which would be favorable for the long term mechanical properties of the bimodal PE as potential high grade pipe materials.