Polymer Structure Prediction by Computer Simulation of Ziegler-Natta Polymerization Based on Charge Percolation Mechanism
Recently, a new charge percolation mechanism (CPM) of the Ziegler-Natta (ZN) polymerization of olefins by supported transition metal (Mt) complexes has been presented: a macromolecular chain is formed by polymerization of the monomer cluster (nM) adsorbed on the support (S) between two immobilized Mt ions, some in the higher (Mtn+1, i.e. acceptors) and the other in the lower (Mtn-1, i.e. donors) oxidation state: (Mtn-1...nM...Mtn+1)/S → (Mtn Mtn)/S + polymer. A special computer program «Lattice» has been developed to simulate olefin polymerization based on CPM using a Monte Carlo procedure. The effects of reaction conditions (Mt concentration, Mt/S ratio, sequence of chemical components addition and time) of ethylene and propylene polymerization by various Mt precursors (TiCl4/MgCl2, CrOx) and supports (MgCl2, SiO2) on molecular mass and molecular mass distribution can be predicted by simulation and confirmed by published experimental results.
Dragan P. Uskokovic, Slobodan K. Milonjic and Dejan I. Rakovic
B. Pilić et al., "Polymer Structure Prediction by Computer Simulation of Ziegler-Natta Polymerization Based on Charge Percolation Mechanism ", Materials Science Forum, Vol. 518, pp. 381-386, 2006