Rate constant of propagation reaction in stationary state of cationic polymerization. Part IV. Frequency factor (polymerisation of styrene catalyzed by iodine)

Abstract

Abstract The pre‐exponential factor (A p ) and the activation energy (ΔE p ≠) of the propagation constant were determined on the cationic polymerization of styrene initiated by iodine in ethylene chloride, the obtained values being about 10 2 l./mole·sec. and 6.5 kcal./mole respectively. The pre‐exponential factor obtained here is much smaller than that of the propagation constant of the radical polymerization. The extraordinarily small A p value was considered to come from the interaction of the counter anion, and from the statistic consideration experimentally obtained k p value was proved to be reasonable.