Modelling Ziegler-Natta polymerization in high pressure reactors

This chapter presents an original study of some unexplored mechanical aspects of the polymerization processes known today as the Ziegler-Natta process, after the names of the Nobel laureates (1963): Karl W Ziegler and Giulio Natta. Polypropylene and polyethylene are the polymers most widely used for innumerable applications. They are obtained from the corresponding monomers (propylene and ethylene) by means of a catalyst triggered reaction in which pairs of monomers share a chemical bond, thus creating a long chain that may contain thousands of elements. The Ziegler-Natta process in its modern version, using spherical catalyst support in high pressure reactors, is the most efficient and economic way of producing polymers of ubiquitous use such as polypropylene and polyethylene. The chapter formulates a new mathematical model for the Ziegler-Natta polymerization process in high pressure reactors. The study presented in the chapter is limited to the theoretical analysis of the model for checking the consistency of the boundary conditions with the structure of the hyperbolic system governing the evolution of the microspheres, according to Li Ta-Tsien's theory.