Hydrogen as a chain terminator in continuous gas phase polymerization of propylene

The effects of hydrogen on both degree and rate of polymerization have been determined for continuous, gas phase polymerization of propylene at industrial reactor conditions. The effects of molecular weight using three modifications of TiCl₃–DEAC catalyst are correlated by Natta's equation, using number average molecular weights determined from polymer melt flow rate. The coefficients of Natta's equation, when correlated against temperature in Arhenius plots, imply that the most active catalyst is diffusion controlled because the activation energy is abnormally low. Hydrogen increases overall polymerization rate. Rate is correlated by modification to Natta's equation that accounts for hypothesized increase in active sites on catalyst surface due to adsorbed molecular hydrogen.