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JOURNAL OF POLYMER ENGINEERING Vol. 22, No. 2, 2002, page 75 Polymerization Kinetics and Modeling of Solution PE Process with Metallocene CatalystsMu-Jen
Young1,2,and Chen-Chi M. Ma1,*
1Department
of Chemical Engineering, National Tsing Hwa University, Hsinchu,
Taiwan, 3004 2Union
Chemical Laboratories, Industrial
Technology Research Institute, Hsinchu,
Taiwan, 30043 ABSTRACT
Polymerization methods of ethylene include the slurry, solution, and gas
phase processes. The solution process for PE not only allows the operation
temperature to reach as high as 300oC, but also produces special
grade polymers particularly for ultra-low density polyethylene (PE). This study
investigates polymerization conditions and kinetics. The commercial constrained
geometry catalyst was used for ethylene polymerization. The kinetic studies were
conducted for metallocene type polymerization, including catalyst activation,
initiation, chain propagation, chain transfer, and termination steps. In
addition, kinetic constants were calculated for the polymerization model.
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. Exactly how solvent type,
reaction temperature, pressure, catalyst concentration, and cocatalyst ratio
affect catalyst activity and molecular weight of polymer was also discussed. Keywords: Metallocene, Polymerization Kinetics, Polyolefin, Solution PE
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