Kinetic Study of Olefin Polymerization with a Supported Metallocene Catalyst. IV. Comparison of Bridged and Unbridged Catalyst in Gas Phase

摘要

A kinetic study of ethylenell-hexene (E/1-H) copolymerization is conducted with a supported bridgedmetallocene catalyst in a gas phase reactor. The investigation into the kinetics ofethylenell-hexene copolymerization includes the effects of opera- tional parameters such as the reaction temperature, pressure, and comonomer concen- tration. On-line perturbation techniques are implemented to determine key kinetic parameters such as the activation energies for propagation and catalyst deactivation. A comparison of the kinetic parameters and behavior is made between the bridged and a previously studied unbridged catalyst. Finally,a two-site model is proposed to explain the observed kinetic behavior with changing reaction temperature and comonomer concentration.