Direct evidence of the second-order dependence of propagation rate on propene concentration in living polymerization with the [t-BuNSiMe(2)Flu]TiMe2/B(C6F5)(3) catalyst

Propene polymerization was conducted with the [t-BuNSiMe(2)Flu]TiMe2/B(C6F5 )(3) catalyst at -50 degrees C at various concentrations of propene. The po lymerization proceeds in a living manner regardless of the propene concentr ation employed. Molecular weight of polymer obtained in a certain polymeriz ation time with low monomer conversion increases with increasing concentrat ion of propene. The logarithmic plot of molecular weight against propene co ncentration gives a straight line with a slope of 1.8, which indicates that the propagation rate is almost of second order with respect to propene con centration.