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

Abstract

Facile construction of sulfur-rich polymers using readily available raw chemicals is an area aggressively pursued but challenging. Herein we use common feedstocks of ethylene oxide (EO), propylene oxide (PO), and carbonyl sulfide (COS) to synthesize copoly(thioether)s which are traditionally produced from unpleasant and difficult to store episulfides. In this protocol, the EO/COS coupling selectively generates a pure poly(ethylene sulfide) (PES) with melting temperature (T m ) values up to 172 C and high yields up to 98%. The EO/PO/COS terpolymerization leads to the incorporation of soft poly(propylene sulfide) (PPS) and hard PES segments together, affording a random PES-co-PPS copoly(thioether) with the complete consumption of EO and PO. Additionally, by simply varying the EO/PO feeding ratio, the obtained copoly(thioether)s possess tunable thermal properties, T m values in the range of 76-144 C, and excellent solubility. These copolymerizations are conducted in one-pot/one-step at industrially favored reaction temperatures of 100-120 C using catalysts of common organic bases, suggesting a facile and practical manner. Especially, the copoly(thioether) exhibits high refractive indices up to 1.68 owing to its high sulfur content, suggesting a broad application prospect in optical materials.

Synthesis and applications of the sulfur containing analogues of cyclic carbonates

“…17b). 96 The formation of the 1,3-dithiolan-2-one is proposed to arise from the cycloaddition of COS to ethylene oxide via a zwitterionic-based mechanism (Fig. 17f ).…”

Directly using H2S to Synthesize Crystalline Poly(thioether‐ester)s via Organocatalysis

“…[48][49][50][51][52][53][54] The introduction of sulfur atoms into the polymer backbones in the form of DOI: 10.1002/macp.202300449 different functional groups can impart special properties into polymers (e.g., thermal, mechanical, electrical, optical properties; and absorption to metal ions). [8,[55][56][57][58][59][60] Therefore, sulfur-containing polymers could be promisingly used as high-performance engineering plastics, [14] metal ion absorbents, [45][46][47]51,61] protonconducting electrolytes, [6,11,30,32,50,53] optical [9,12,[22][23][24]31,35,41,47] and photophysical materials. [45,46,54] Thus, it's demanding for the development of sustainable routes for the preparation of sulfur-containing polymers.…”

“…[64,79] Using metal or organic catalysts, kinds of well-defined polythioethers, polythiocarbonates have been obtained. These sulfur-containing polymers have been tested for applications such as optical materials [9,12,23,24,31,35] and dielectric elastomers. [10,11,32] Although thiol-ene/yne Michael additions have been widely applied in polymerizations and the modifications of polymers as a powerful method, to the best of our knowledge, the direct use of H 2 S as a monomer for polymerization is quite few, possibly due to its rotten egg odor and highly toxicity.…”

“…Sulfur‐containing polymers, benefitting from the versatile reactivity of sulfur atoms, show great diversity in species of polymers. Such as polythioesters, [ 1–5 ] polythioethers, [ 6–14 ] polydisulfides, [ 15–19 ] polythiocarbonates, [ 9,20–38 ] polythiourethanes, [ 39–41 ] polythioamides [ 42–47 ] and polythioureas. [ 48–54 ] The introduction of sulfur atoms into the polymer backbones in the form of different functional groups can impart special properties into polymers (e.g., thermal, mechanical, electrical, optical properties; and absorption to metal ions).…”

Chemical recycling of CO2-based polycarbonates to sulfur-containing polymers

“…46,47 The synthesis of poly(thioether)s is accomplished by two sequential reactions, involving the coupling reaction between COS (CS 2 ) and epoxides followed by decarboxylative ring-opening polymerization. This methodology has also been utilized to prepare crystalline poly(thioether)s 48 and repurpose poly(monothiocarbonate)s (PMTCs) to poly (thioether)s. 49 Compared with PMTCs, the obtained poly (thioether)s exhibit higher thermal decomposition temperatures, higher refractive indices, and lower glass transition temperatures.…”