How can pH value during catalyst preparation affect the performance of vanadium-modified (SiO2/MgO/ MgCl2)•TiClx Ziegler-Natta polyethylene catalysts

Document Type : Original research


State Key Laboratory of Chemical Engineering,East China University of Science and Technology, Meilong Road 130, Shanghai 200237, China


Vanadium-modified (SiO2/MgO/MgCl2)•TiClx Ziegler-Natta catalysts were prepared through co-impregnation of water-soluble magnesium and vanadium salts under different pH values. Several key factors such as pH value of co-impregnation solution during catalyst preparation, catalyst performances including catalytic activity, ethylene/1-hexene copolymerization and hydrogen response were investigated. It is found that the components, structures and performance of the catalysts are obviously affected by changing the pH value (pH=5, 7 and 9) of co-impregnation solution. An appropriate pH value (pH=7) can maximize catalytic activity and hydrogen response, while lower pH value (pH=5) is beneficial to the 1-hexene incorporation. The GPC results show that the polymers obtained have high average molecular weight.


Main Subjects

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Volume 5, Issue 1
January 2018
Pages 31-45
  • Receive Date: 10 February 2017
  • Revise Date: 21 August 2017
  • Accept Date: 23 August 2017
  • First Publish Date: 01 January 2018