Cationic polymerization of cyclic imines. I. 1,3,3‐trimethylazetidine

The polymerization of 1,3,3‐trimethylazetidine (TMA) under the influence of various cationic initiators has been studied. At room temperature no polymers were formed, but at 60°C or higher, polymerization went to complete conversion. The kinetics of the polymerization were studied with triethyloxonium tetrafluoroborate as initiator and nitrobenzene as solvent. The time‐conversion curves showed that the polymerization is of first order with respect to monomer and initiator. From conductivity measurements and model reactions it was concluded that the initiation reaction (alkylation of monomer) is quantitative and instantaneous. Second monomer addition experiments showed that the polymer is of the “living” type. The absence of a termination reaction is attributed to the high basicity of the monomer compared to that of the polymer. At 78°C the rate‐constant of propagation was found to be 1,4 · 10−4 dm3 · mol−1 · s−1. The energy of activation is 19 kcal · mol−1.