Kinetic Studies on Ziegler-Natta Polymerization-An Interpretation of Results

The phenomenological behaviour shown by many Ziegler-Natta catalyst systems is outlined and the factors controlling the observed rate-time profiles are discussed in the light of existing kinetic models. Results for C* and derived values of kp are presented for the polymerization of propylene and 4-methylpentene-1 by MgCl2/EB/TiCl4-Al (i-Bu)3 catalysts. The concentrations and activities of polymerization centres giving rise to atactic and isotactic polymer in propylene polymerization are evaluated. The higher overall rates observed in both propylene and 4-methylpentene-1 polymerization are discussed in terms of C* and kp values. Increased values of C* obtained for higher α-olefin polymerization are also presented.