Selective copolymerization of CS2 and oxetane to synthesize poly(ether–thioether–carbonate)

Abstract

Carbon disulfide (CS₂) is a low-cost, abundant sulfur-derived feedstock that can be used to synthesize value-added sulfur-containing polymers. This study reports the synthesis of poly(ether–thioether–carbonate) from CS₂ and oxetane (OX) using an organocatalyst. The effects of temperature, OX/CS₂ feed ratios, and various Lewis pairs on the polymer chain composition were examined. Three distinct repeating units, i.e., ether, thioether, and carbonate, can be regulated by varying the OX/CS₂ feed ratios. Increasing the CS₂/OX molar ratio substantially induced the oxygen/sulfur exchange reaction (O/S ER), enabling efficient sulfur incorporation even under ambient conditions while completely suppressing the formation of ether linkages. This work provides a metal-free catalytic pathway for utilizing the O/S ER to synthesize sulfur-containing polymers.