Kinetics of the polymerization of ethylene with a ziegler‐natta catalyst. I. Principal kinetic features

The kinetics of the polymerization of ethylene was studied in an apparatus which is described. A stable catalyst combination [Al(C2H5)2Cl/γ‐TiCl3] which does not change during the polymerization was used. Conditions are defined under which the reaction is (a) independent of mass transfer rate (b) controlled by mass transfer. After an initial period, the polymerization proceeds at constant rate until the slurry is too thick to stir adequately. The catalyst is neither occluded nor deactivated so that unlimited quantities of polymer can be made from a given amount. When the reaction is not controlled by mass transfer, the rate is linearly dependent on monomer and TiCl3 concentration and is independent of Al(C2H5)2Cl. Hydrogen reduces the rate of the polymerization at a constant partial pressure of ethylene.