Comparative study on novel Poly(alkylene sulfide)s with modulated thioether linkages and flexible alkylene spacers

One‐pot, one‐step, and selective terpolymerization of ethylene oxide, propylene oxide, and COS to copoly(thioether)s with tunable thermal properties

“…As expected, a single chemical shift was observed in both solid-state 1 H and 13 C NMR spectra, 2.68 and 30.95 ppm, respectively (Figure 1). No other 13 C resonances in C═O or C═S region (150-220 ppm) 28,38 were observed, indicating that the obtained solid is a pure PES without any poly(carbonate) or poly(thiocarbonate) formed. Also, the FT-IR spectrum showed characteristic peaks of CH 2 rocking and C S C stretching at 724 and 670 cm À1 , respectively, which further confirms the structure analysis of PES (Figure S2).…”

“…The 1 H NMR spectrum of the purified polymer shows the characteristic peaks of both PES and PPS (Figure 2A). The resonance peak at 2.77 ppm is assigned to CH 2 of PES and the resonance 1 H NMR and (B) 13 C NMR spectra of the produced PES peaks at 2.85-3.10, 2.55-2.70, and 1.38 ppm are attributed to CH and CH 2 , CH 2 , and CH 3 of PPS, respectively. 12,24 13 C NMR spectrum with the cooperation of 1 H- 13 C HSQC and 1 H- 13 C HMBC NMR spectra confirmed the PES-co-PPS structure.…”

“…Aliphatic poly(thioether)s are extremely promising in a multitude of applications such as energy storage, heavy metal removal, optical, biological, and self-assembled materials. [1][2][3][4][5][6][7][8][9] The typical synthetic methods of aliphatic poly(thioether)s include (1) ring-opening polymerization (ROP) of episulfides, 4,[10][11][12] (2) nucleophilic substitution of dihalides with dithiols, 10,13,14 and (3) thiol-ene click polymerization of dithiols and dienes. [15][16][17][18][19][20][21] However, the feasible monomers of these methods are intensely difficult to obtain on a large scale 12,22 and always require special storage owing to their exceedingly high reactivity.…”

“…We noticed that poly(ethylene sulfide) (PES), traditionally produced from the ROP of ethylene sulfide (ES), is highly crystalline and exhibits high melting temperature ( T m ) values up to 216°C 33 . However, the reported PES is insoluble in most solvents, 10,13,34 which exceedingly limits the large‐scale application of this material. In contrast, poly(propylene sulfide) (PPS), produced from the ROP of propylene sulfide (PS), is soft and soluble in common organic solvents and exhibits low T g values of around −50°C 35 .…”

“…24 Nevertheless, the obtained poly(thioether)s are amorphous and exhibit relatively low glass-transition temperature (T g ) values in the range of À58 to 53 C. As a possible solution, crystallization can enable polymers with enhanced physical properties like polyethylene and polypropylene. 32 We noticed that poly(ethylene sulfide) (PES), traditionally produced from the ROP of ethylene sulfide (ES), is highly crystalline and exhibits high melting temperature (T m ) values up to 216 C. 33 However, the reported PES is insoluble in most solvents, 10,13,34 which exceedingly limits the large-scale application of this material. In contrast, poly(propylene sulfide) (PPS), produced from the ROP of propylene sulfide (PS), is soft and soluble in common organic solvents and exhibits low T g values of around À50 C. 35 Therefore, we envisioned the synthesis of a copoly(thioether) to incorporate both the hard PES and the soft PPS segments using commercially available feedstocks of COS, ethylene oxide (EO), and propylene oxide (PO).…”