Self-immobilizing catalysts and cocatalysts for olefinpolymerization

Abstract

Homogeneous catalysts for olefin polymerization such as metallocene or half-sandwich complexes containing the metals titanium, zirconium and hafnium, or other transition-metal coordination complexes can be functionalized with alkenyl groups and have then the potential to copolymerize with olefins to give heterogeneous catalysts. In a similar manner metallacyclic metallocene complexes with a metal–carbon σ bond allow the catalytic insertion of olefins into this bond and produce heterogeneous catalysts. It is also possible to functionalize the active species of the cocatalyst methylalumoxane (MAO) and use it for self-immobilization processes. The high excess of MAO that is necessary in homogeneous solution can be reduced by more than 90% with this method.