Poly(trimethylene monothiocarbonate) from the Alternating Copolymerization of COS and Oxetane: A Semicrystalline Copolymer

A semicrystalline poly(trimethylene monothiocarbonate) (PTMMTC) has been synthesized via the selective and alternating copolymerization of carbonyl sulfide and oxetane. This reaction was catalyzed by (salen)CrCl accompanied by organic bases over a wide range of temperatures from 40 to 130 °C. PTMMTC is shown to exhibit similar crystallization behavior to high-density polyethylene (HDPE), i.e., being spherulite and possessing melting temperatures ( T m ) up to 127.5 °C and a degree of crystallinity ( X c ) of up to 71%. Moreover, PTMMTC has a wide processing temperature window of ca. 100 °C.