Influence of π-complexing agents on the anionic polymerization of styrene with lithium as counterion in cyclohexane. 3. Effect of tetraphenylethylene

The propagation reaction in anionic polymerization of styrene with lithium as counterion in cyclohexane has been investigated for four different concentrations of tetraphenylethylene (TPhE) in the range of living end concentrations between 10−5 and 10−3 M at 20 °C. The values of the apparent dissociation constant of PStLi dimer and the weighted rate constants of all unassociated species were obtained for all four investigated concentrations of TPhE. The mechanism, already used in the case of durene, was also applied in this system and the values of the relevant absolute propagation rate constants of the two reactive monomeric species have been derived from the kinetic results. The absolute propagation rate constant of PStLi·TPhE is much lower than that of PStLi. The complexation constant of PStLi with one molecule of TPhE is more than 100 times larger than that of PStLi with one molecule of durene.