Crystalline and Elastomeric Poly(monothiocarbonate)s Prepared from Copolymerization of COS and Achiral Epoxide

Abstract

The semicrystalline poly(monothiocarbonate)s were prepared by the copolymerization of carbonyl sulfide (COS) and ethylene oxide, an achiral epoxide, using a bifunctional chromium(III) complex as catalyst. The resultant copolymer, possessing perfectly alternating structure, high molecular weight, and narrow polydispersity, has a melting temperature of 128.2 °C, with a melting enthalpy up to 75.44 J/g. Moreover, an ABA triblock copolymer containing the "hard" semicrystalline poly(ethylene monothiocarbonate) (A) and the "soft" amorphous poly(propylene monothiocarbonate) (B) is synthesized by stepwise addition of epoxides. The tensile testing demonstrates the triblock copolymer may have the potential as a thermoplastic elastomer.

Enabling Oxygen–Sulfur Exchange Reaction to Produce Semicrystalline Copolymers from Carbon Disulfide and Ethylene Oxide

“…[ 21–25 ] Thereof, O–S ER in COS‐epoxide copolymerizations could be completely inhibited. Of interest, semicrystalline copolymers were obtained by the copolymerization of COS with ethylene epoxide (EO) [ 26 ] (A), or oxetane, [ 27 ] owing to the strong chain interaction of the unsubstituted poly(monothiocarbonate)s. For example, the melting point ( T m ) and glass transition temperature ( T g ) of the COS‐EO copolymers are 125 and –5 °C, respectively. In contrast, the alternating CO 2 ‐EO copolymer with [OC( O)O] units is completely amorphous with a T g of –30 °C (Scheme 1B).…”

Highly Efficient One-Pot Synthesis of COS-Based Block Copolymers by Using Organic Lewis Pairs

“…The copolymerization of COS with various epoxides (and oxetane) provided a series of functional poly(monothiocarbonate)s [ 17 , 18 , 19 , 20 , 21 , 22 ]. Introduction of sulfur atoms in the backbone brought polymers with remarkable optical property and heavy-metal recognition ability, which enabled them potentially to be used as photoconductive fibers and heavy-metal scavengers [ 10 ].…”

“…Since our first work on the alternating copolymerization of COS and propylene oxide (PO) [ 10 ], the conversion of COS to polymers has made significant advances [ 6 , 16 ]. However, reports on constructing block copolymers containing poly(monothiocarbonate) block are rare [ 20 , 23 ]. Ren and coworkers [ 20 ] reported the synthesis of a tri-block copolymer, poly(ethylene monothiocarbonate)- b -poly(propylene monothiocarbonate)- b -poly(ethylene monothiocarbonate) (PEMC- b -PPMC- b -PEMC), catalyzed by a highly active bifunctional (salen)Cr(III) complex with subsequent adding of monomers.…”

“…However, reports on constructing block copolymers containing poly(monothiocarbonate) block are rare [ 20 , 23 ]. Ren and coworkers [ 20 ] reported the synthesis of a tri-block copolymer, poly(ethylene monothiocarbonate)- b -poly(propylene monothiocarbonate)- b -poly(ethylene monothiocarbonate) (PEMC- b -PPMC- b -PEMC), catalyzed by a highly active bifunctional (salen)Cr(III) complex with subsequent adding of monomers. Very recently, our group [ 23 ] reported a ABA block copolymer with precise structure, polystyrene- b -poly(propylene monothiocarbonate)- b -polystyrene (PS- b -PPTMC- b -PS) via atom transfer radical polymerization (ATRP) through several operation steps.…”

“…Very recently, our group [ 23 ] reported a ABA block copolymer with precise structure, polystyrene- b -poly(propylene monothiocarbonate)- b -polystyrene (PS- b -PPTMC- b -PS) via atom transfer radical polymerization (ATRP) through several operation steps. Unfortunately, metal residues of the catalyst in these copolymers limited their potential applications [ 10 , 19 , 20 , 23 ]. Sulfur-containing block copolymers via metal-free route is urgently needed.…”