Kinetic study of olefin polymerization with a supported metallocene catalyst. II. Ethylene/1-hexene copolymerization in gas phase

A kinetic study of ethylene/1-hexene copolymerization is conducted with a s upported metallocene catalyst in a gas-phase reactor. The investigation int o the kinetics of ethylene/1-hexene copolymerization includes the effects o f operational parameters such as the reaction temperature, pressure, and co monomer concentration. The large variations in gas-phase composition using only an initial charge of 1-hexene are illustrated by experiment. To remedy this, the ability to control the comonomer composition of 1-hexene online for the entire duration of the reaction is demonstrated. Online perturbatio n techniques are implemented to determine key kinetic parameters such as th e activation energies for propagation and catalyst deactivation. From press ure perturbation results, a reaction rate order close to 1 is obtained for ethylene in the presence of 1-hexene. Finally, all the parameters obtained from the study are compared to those determined from ethylene-propylene (E- P) copolymerization. (C) 2001 John Wiley & Sons, Inc.