Dynamic Model of the Homopolymerization of Propylene with the Me₂Si(2-Me-Ind)₂ZrCl Catalyst: The Effect of Reaction Variables

The effect of four variables—temperature, propylene pressure, Al/Zr ratio, and catalyst concentration—on catalyst productivity and molecular weight of the polymer synthesized with Me₂Si(2-Me-Ind)₂ZrCl₂ was studied. A mathematical model was developed based on the method of the moments that fit the experimental data. A special effect was seen with respect to the co-catalyst (MAO) on productivity, and therefore it was necessary to add deactivation-reactivation mechanisms associated with MAO to the model. With respect of the molecular weight of the polymer, a bimolecular transfer reaction associated with the active center was added to fit the experimentally observed data.

Keywords:

• Propylene polymerization
• Metallocene catalyst
• Mathematical modeling
• Reaction mechanism

ACKNOWLEDGMENTS

The authors acknowledge CONICYT (project FONDAP 11980002 and scholarships) for their financial support. Also, the authors acknowledge Dr. J. Soares for help in the discussion.

Notes

⁽¹⁾A₀ [1/s] or [m³/l · s].

⁽²⁾k₂ = − 0.0054 + a2(1/T) + a3(1/T)².

k_i = 0.001 (lt/mol s) and k₃ = 0.00001 (l/s).