Anionic and pseudoanionic polymerization of ϵ‐caprolactone

Anionic polymerization of ϵ‐caprolactone conducted in THF solvent has been compared with polymerizations initiated with aluminium alkoxides. The latter processes have been kinetically analysed as the pseudoionic processes, i. e. with propagation proceeding by insertion. In the pseudoanionic reaction active species are aggregated. The methods of solving kinetic schemes involving aggregation ⇋ deaggregation equilibrium, followed by the chain growth on deaggregated species are described. These kinetic methods have been used to determine the propagation rate constants. The relationships between structures of the growing species and their reactivities have thus been determined.