MODELING OF ZIEGLER-NATTA OLEFIN POLYMERIZATION

In this work we provide an overview of various aspects of modelling he terogeneous Ziegler-Natta polymerization. Starting from a detailed des cription of the polymer particle growth, we compare the model results with two series of experimental data obtained with slurry and gas-phas e laboratory reactors, respectively. From the comparison it follows th at the model provides a reliable description of both the kinetic behav iour of the reaction and of the influence of resistances to mass and h eat transport. An aspect of specific interest refers to the descriptio n of the molecular weight distribution. A method for the detailed anal ysis of these distributions is proposed and the results compared with experimental data. Finally, a steady-state analysis of particle behavi our is performed, allowing the determination of critical situations le ading to overheating (and then melting) of the polymer particle.