KINETIC STUDY ON PROPENE POLYMERIZATION OVER TICL3-AL(C2H5)2H CATALYST

The propene polymerization over TiCl3-Al(C2H5)2H catalyst has been kinetically studied. The polymerization rate increases rapidly to a maximum and then gradually decreases to a stationary rate (Rm) with time. The rate after passing a maximum is expressed by [formula omitted] where R0 is the extrapolated rate at t=0 and k3 decay parameter. The stationary rate is expressed by the Langmuir-Hinshelwood type equation: [formula omitted] where, k and KA are constants, [A] concentration of A1(C2H3)8H and P propene pressure. It was confirmed that R∞ is reversible with respect to [A]. An aging effect of TiCl8 in a concentrated solution of Al(C2H3)2H on the maximum rate has not been observed. It was found in this system that the stereoregularity of produced polymer increased with increasing Al(C2H3)2H concentration used in the polymerization. By measuring the number-average molecular weight under various conditions, the concentration of polymerization centers and the rate constants of elementary reactions were determined. In this connection, a correct kinetic method for determining of the number of the centers was proposed, criticizing the conventional method. Some kinetic features of this polymerization have been discussed. © 1979, The Chemical Society of Japan. All rights reserved.