Method for sulfonating polyether sulfone with dimethyl sulfoxide solvent and preparing its thin film

Abstract

This invention discloses a method for sulfonating polyether styrene (PES) with dimethyl sulfoxide (DMSO) solvent and preparing its thin film, effectively replacing existing highly toxic organochlorine solvents and conforming to green chemistry and sustainable processes. The method involves dissolving polyether styrene (PES) in the low-toxicity green solvent dimethyl sulfoxide (DMSO), adding a sulfonating agent dropwise to initiate the reaction, and then washing and drying to obtain sulfonated polyether styrene (SPES) powder. Subsequently, the obtained SPES is blended with a hydrophilic polymer, and a thin film is prepared using DMSO as the solvent via a phase inversion method, increasing its proton conductivity to 10⁻¹ S / cm, surpassing the level of existing commercial membrane materials. This membrane simultaneously possesses high hydrophilicity and excellent thermal stability, effectively overcoming the problems of hydrophobic scaling and membrane blockage of traditional PES membranes, and can be widely used in water treatment, biomedicine, and energy storage fields, demonstrating high industrial application potential.

Claims

1. A method for sulfonating poly(ether sulfone) using dimethyl sulfoxide solvent, comprising the following steps: placing poly(ether sulfone) (PES) and dimethyl sulfone (DMSO) into a container according to a set weight percentage, heating and stirring until completely dissolved to form a base solution; slowly adding a sulfonating agent dropwise to the base solution according to a set degree of sulfonation, and stirring until a precipitate is formed; washing the precipitate with deionized water, and drying the precipitate to obtain sulfonated poly(ether sulfones) (SPES) powder.

2. The method for sulfonating polyether phosphate with dimethyl phosphate solvent as described in claim 1, wherein the polyether phosphate and dimethyl phosphate are heated and stirred at 80-90°C until they are completely dissolved.

3. The method for sulfonating polyether sulfone with dimethyl sulfoxide solvent as described in claim 1, wherein the sulfonating agent is slowly added dropwise to the base solution and stirred at 25-40°C for 2-8 hours until a precipitate is formed.

4. The method for sulfonating polyether sulfone with dimethyl sulfoxide solvent as described in claim 1, wherein a portion of the sulfonating agent is slowly added dropwise to the base solution, and the reaction is stirred at 80-90°C for 1 hour. After the precipitate is formed, the sulfonating agent is slowly added dropwise again until the set degree of sulfonation is reached, and the reaction is continued to be stirred at 80-90°C for 1 day.

5. The method for sulfonating polyether sulfone with dimethyl sulfoxide solvent as described in claim 1, wherein the sulfonating agent is one or a combination of two or more of sulfuric acid, methanesulfonic acid, or sulfonic anhydride.

6. A method for preparing a thin film using the method of sulfonating polyether sulfonium with dimethyl sulfoxide solvent as described in any one of claims 1 to 5, comprising the following steps: placing sulfonated polyether sulfonium, dimethyl sulfoxide, and a hydrophilic polymer into a container according to a set weight percentage, heating and dissolving to form a casting solution; uniformly casting the casting solution onto a substrate at room temperature, then placing it in a room temperature deionized water precipitation tank, and controlling the phase transition by adjusting the operating time, temperature, and humidity; after the thin film precipitates and separates from the substrate, washing with deionized water by shaking, and drying to obtain a sulfonated polyether sulfonium thin film.

7. The method for preparing a thin film by sulfonating polyether sulfone with dimethyl sulfoxide solvent as described in claim 6, wherein the hydrophilic polymer is one or a combination of two or more of polyethylene glycol (PEG), polyethylene oxide (PEO) or polyvinylpyrrolidone (PVP).

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