Ring‐opening polymerization of α,β‐disubstituted oxiranes by α‐methoxyphenylmethylium hexachloroantimonate

Abstract α‐Methoxyphenylmethylium hexachloroantimonate was used as a novel initiator for the polymerization of α,β‐disubstituted oxiranes such as cyclohexene oxide (CHO) and 2‐butene oxide (trans and cis) (2‐BO) at −78°C with dichloromethane or dichloromethane‐toluene mixtures as solvents. The CHO polymerization mixture became turbid and the polymer precipitated in dichloromethane. The CHO polymerization proceed quantitatively in dichloromethane–toluene mixtures. The molecular weight distribution of polyCHO obtained was bimodal regardless of the solvent used. The polymerization of trans‐2‐BO was heterogeneous in both dichloromethane and dichloromethane–toluene mixture. The polymerization mixtures of cis‐2‐BO were transparent but reached a limit yield which was less than the polymer yield of trans‐2‐BO. Furthermore, the microstructure of the poly2‐BOs were analyzed by Vandenberg's method and the results confirmed Vandenberg's finding that inversion of configuration occurs in the propagation step.