Factors affecting kinetics in slurry type coordination polymerization

Giannini has found, in PP slurry polymerization at 65 deg C with TiCl sub 4 /MgCl sub 2 --Et sub 3 Al catalysts, the propagation rate constant as well as the active site concentration to decrease with reaction time. These phenomena have been explained by assuming the presence of two types of stereospecific centers, having different propagation rate constants and lifetimes, rather than assuming changes in propagation rates of individual active sites. These studies also indicate that the number of active centers does not change with change in monomer concentration. In that connection the effects of Al-alkyl concentration and temperature have been studied. The propagation rate constant wsa found to be constant while the active site concentration was fond to increase with increasing Et sub 3 Al concentration. Increasing the temperature caused the propagation rate constant to increase, while the active site concentration remained constant. Graphs. 177 ref.--AA