o-술포벤조산 무수물을 개시제로 사용하여 프로필렌술피드를 괴상 중합시킨 결과 양성이온 메카니즘에 의하여 중합한다는 것이 판명되었다. 생성된 폴리머를 분석한 결과 이 폴리머는 술포늄양이온과 술폰산음이온을 폴리머 사슬에 가지고 있다는 것이 판명되었다. 음이온과 양이온의 농도가 거의 같으며 이것은 고분자양성이온임을 나타낸다. 중합계중에 존재하는 수분이 조촉매로 이용되었을 가능성은 없으며 말단기 분석을 이용하여 중합메카니즘을 규명하였다.
Bulk polymerization of propylene sulfide with o-sulfobenzoic anhydride as initiator was carried out and the polymerization proceeded by a zwitterionic mechanism. Chemical and spectroscopic investigation of the purified polymer revealed that the polymer contained two end groups-thiolester of benzoic acid o-sulfonate anions and acyclic tert-sulfonium ions which were formed by termination of episulfonium ions with sulfide groups in the polymer chains. The concentration of sulfonate anions was nearly the same as the concentration of acyclic tert-sulfonium ions, as expected for macrozwitterions. The cocatalysis mechanism by a trace of water was excluded and the other possible mechanisms were discussed on the basis of end group analysis.
