Propylene polymerization through supported metallocene/ MAO catalysts: Kinetic analysis and modelling

Several propylene polymerizations are carried out with supported metallocene catalyst, prepared by reaction of silica gel with methylaluminoxane and then with rac‐dimethylsi‐lanediylbis(indenyl)zirconiumdichloride. The rate–time curves obtained are analyzed to understand the influence of support and triisobutylaluminium on the reaction. As a first attempt to model this system we developed a partially new praticle growth model, based on a shell by shell fragmentation hypothesis (gradual break‐up from the outside to the inside of the particle), and a final multigrain structure of the particle. A kinetic scheme including the TIBA interaction with the supported catalyst is also presented. The model prediction and the experimental data are compared for the rate–time curves and polymer properties.