Study on ethylene polymerization by homogeneous Cp2ZrCl2/methylaluminoxane catalyst system

Ethylene polymerization was carried out using Cp2ZrCl2 and methylaluminoxane (MAO) as cocatalyst. In this work temperature and [MAO]/[Cp2ZrCl2]([Al]/[Zr]) molar ratio were varied. The highest value of catalyst activity was obtained at 60 °C when [Al]/[Zr] molar ratio=500 was employed. A small increase in catalyst activity was only observed at 60 °C when the [Al]/[Zr] molar ratio was increased to 2000. The produced polyethylenes were characterized by differential scanning calorimetry (DSC) and SEC analysis.