Repurposing poly(monothiocarbonate)s to poly(thioether)s with organic bases

This work reports a unique one-pot/one-step route to rapidly produce poly(thioether)s from poly(mono-thiocarbonate) (PMTC), a sulfur-containing polymer, using commercially available organic bases. The process started with the degradation of PMTC to a cyclic monothiocarbonate that generated an episulfide via a decarboxylative reaction. Then the episulfide underwent ring-opening polymerization. Organic bases catalyzed the degradation of PMTC and initiated the ring-opening of the generated cyclic monothiocarbonate. This process was successfully expanded to transform several PMTCs to the corresponding poly(thioether)s. The resultant poly(thioether)s exhibited higher thermal decomposition temperatures (up to 311 degrees C), higher refractive indexes (ca. 1.62) and lower glass transition temperatures (-48 degrees C) than those of the corresponding PMTCs. This work provides a polymer-to-polymer pathway for repurposing poly (monothiocarbonate)