Homo- and copolymerization with a highly active Ziegler–Natta catalyst

The copolymerization of ethylene and 1-butene with a highly active Ziegler–Natta catalyst has been investigated at different temperatures. The r parameters and the propagation rate constants have been determined. From the temperature dependence of the rate constants, entropy and enthalpy values have been calculated. These data show the enthalpy values to be small in comparison to entropy, which means that these processes are predominantly controlled by entropic factors.