POLYMERIZATION KINETICS AND MODELING OF SLURRY ETHYLENE POLYMERIZATION PROCESS WITH METALLOCENE/MAO CATALYSTS

Abstract Polymerization methods of ethylene include the slurry, solution, and gas-phase processes. This study investigates polymerization conditions and kinetics under slurry process. Typical metallocene catalyst/cocatalyst Cp2ZrCl2/MAO system was used for ethylene polymerization. Two kinds of polymerization kinetics were compared in this study, multiple active-site model and transfer-effect model. The kinetic studies used metallocene-type polymerization kinetics, including catalyst activation, initiation, chain propagation, chain transfer, and termination steps. In addition, kinetic constants of polymerization reaction model were calculated. Calculation results of catalyst activity and molecular weight were compared with experimental results, indicating their good correlation. Moreover, the conventional polymerization was modified to accurately predict the molecular weight behaviors under various reaction conditions with the proposed transfer-effect model. Exactly, how reaction time, pressure, catalyst concentration, and cocatalyst ratio affect catalyst activity and molecular weight of the polymer were also discussed. Keywords: MetallocenePolymerization kineticsPolyolefinSlurry PE ACKNOWLEDGMENTS The authors would like to thank the Ministry of Economic Affairs, Taiwan, and R.O.C. for financially supporting this research.