Significant increases in the activity of vanadium(III) amidinate catalysts for ethylene polymerization have been obtained by immobilization on a MgCl2-based support prepared by reaction of AlEt3 with a MgCl2/ethanol adduct. Catalyst immobilization and activation on this type of support prevents the rapid decay in activity observed under homogeneous polymerization conditions with unsupported catalysts. Stable polymerization activity is also observed with analogous titanium(III) complexes. Polyethylene with narrow molecular weight distribution and spherical particle morphology is obtained without reactor fouling.
Severn, J. R., Duchateau, R., & Chadwick, J. C. (2005). Immobilization and activation of vanadium(III) and titanium(III) single-site catalysts for ethylene polymerization using MgCl2-based supports. Polymer International, 54(5), 837-841. https://doi.org/10.1002/pi.1779