Polymerization of cyclic sulfides

The ring‐opening polymerizations of cyclic sulfides containing three‐, four‐, and fivemembered rings were studied. In conjunction with these polymerizations, the relative basicities of the cyclic sulfides employed were also investigated. Polymerizations were effected by the use of phosphorus pentafluoride, boron trifluoride ethyl ether, triethylaluminum, and trimethyloxonium tetrafluoroborate. The resulting polymers were oxidized to the sulfones and differential thermal analyses were obtained on the sulfide polymers as well as the sulfone analogs.