Polyarylether containing pyridine group and thioether group as well as preparation method and application of polyarylether

Abstract

The invention relates to the technical field of polymer synthesis, in particular to polyarylether containing pyridine groups and thioether groups as well as a preparation method and application of the polyarylether. A pyridine-containing bisphenol monomer, a 4, 4 '-dihydroxy diphenyl sulfide monomer and a dihalo monomer X-Ar-X are used as raw materials, alkali, alkali metal or salt of alkaline earth metal is used as a catalyst, and solution polycondensation is carried out in an aprotic polar solvent to prepare the pyridine-containing dihydroxy diphenyl sulfide. The diphenyl sulfide structure in the molecular chain of the obtained polymer endows the molecular chain with flexibility, the regularity of the molecular chain can be improved, crystallization is more facilitated to obtain a partially crystallized polymer, the limitation of pyridyl-containing agglomerated arylether on application is overcome, swelling of water or a solvent and the like on a membrane can be effectively inhibited, and the polymer has good application prospects. Particularly, the adverse effect of poor membrane stability caused by high swelling of the membrane due to water when the membrane serves as an ion exchange membrane to be applied to a flow battery is avoided. And the polyarylether containing the pyridine group and the thioether group can provide potential thioether crosslinking points with accurate and controllable quantity, so that the swelling resistance and the chemical stability of the membrane material are improved.

Description

Technical Field

[0001] This invention relates to the field of polymer synthesis technology, specifically to a polyarylene ether containing pyridine and thioether groups, its preparation method, and its application. Background Technology

[0002] Polyaryl ethers are a class of high-performance specialty engineering plastics whose molecular backbone consists of aromatic rings and ether bonds. This unique chemical structure endows them with excellent comprehensive properties, including superior heat resistance, outstanding mechanical properties, good dimensional stability, and chemical corrosion resistance, making them widely used in electronic instruments, meters, aerospace, and other fields. Soluble polyaryl ethers, with their excellent film-forming properties, are widely used as organic separation membrane materials to prepare ultrafiltration membranes, nanofiltration membranes, reverse osmosis membranes, ion exchange membranes, bipolar membranes, etc., and are widely used in water treatment, electrodialysis, flow batteries, fuel cells, water electrolysis devices, and other fields.

[0003] As is well known, polyarylethers such as polyetheretherketone (PEEK) and polyphenylene sulfide (PPS) are partially crystalline polymers, exhibiting resistance to solvent swelling and poor solubility in common solvents. Elsevier's Chemical Engineering Journal (2020, 386, 124086) reported partially crystalline PEEK membranes, which possess excellent solvent resistance; however, the preparation process for this membrane material is complex. Crosslinking is also an effective means to improve the mechanical properties, dimensional stability, and chemical stability of membrane materials. However, crosslinking usually requires the addition of small-molecule crosslinking agents, which often leads to difficulties in controlling the degree of crosslinking, easily resulting in over-crosslinking and causing a sharp deterioration in membrane performance, especially membrane flux, and increased mechanical brittleness. Introducing a controllable amount of crosslinkable groups into the polymer chain segments can easily achieve precise control of the degree of crosslinking. The introduced crosslinkable groups, such as sulfide groups, can undergo thermal crosslinking reactions through heating or radiation crosslinking through irradiation, making industrial-scale implementation easy. For example, literature reports the introduction of irradiation-crosslinkable thioether bonds into polyaryletherketones (PAKs), followed by crosslinking via electron beam irradiation after material molding, which increases the heat resistance and solvent resistance of these materials (Journal of Chemical Research in Chinese Universities, 2005, 26, 1180-1182, Synthesis and Electron Beam Irradiation Study of Thioether-Containing Soluble Polyaryletherketones). Furthermore, crosslinkable PAK polymers can also be used in high-performance membrane materials, composite matrix resins, thermosetting plastics, coatings, adhesives, and many other applications.

[0004] With the development of science and technology, existing polyarylene ether materials can no longer meet the performance requirements of special engineering plastics in high-tech fields, thus urgently requiring the development of new polyarylene ether materials. For example, separation membranes often use soluble polyarylene ether ketones and polyarylene ether sulfones as substrates. However, to increase flux, ion conductivity, membrane selectivity, etc., the membrane material often needs to possess high hydrophilicity or a sufficient number of ion exchange groups. This usually requires complex functionalization modification steps such as sulfonation or chloromethylation-amineation, which generally suffer from drawbacks such as complex processes, poor controllability, and poor environmental friendliness (generating large amounts of waste acid, using highly toxic chloromethylation reagents, etc.). All of the aforementioned fields have created an urgent need for functionalizable polyarylene ethers. Therefore, introducing potentially functionalizable active groups into polyarylene ethers is a hot topic in the development of new polyarylene ether materials.

[0005] Chinese patent CN105837814B discloses a pyridine-side-group-containing polyaryl ether and its preparation method. This method directly introduces precisely controllable amounts of pyridine groups into the polyaryl ether material, eliminating highly polluting and complex processes such as chloromethylation and amination. However, Elsevier's Journal of Power Sources reported in 2021, 506, 230128 that the ion exchange membrane prepared from this material suffers from severe swelling, reaching as high as 28.6% in phosphoric acid, which seriously affects the mechanical strength, dimensional stability, and chemical stability of the membrane material. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a polyaryl ether containing pyridine and thioether groups, its preparation method, and its applications. From a molecular structure design perspective, a polyaryl ether containing pyridine and thioether groups is prepared through polymer synthesis. The flexible diphenyl thioether structure in the molecular chain improves the regularity of the molecular chain, which is more conducive to obtaining partially crystalline polymers. This overcomes the limitations of pyridine-containing polyaryl ethers in application. When used as separation membranes or ion exchange membranes, it can effectively suppress the swelling of the membrane caused by water or solvents, especially when used as an ion exchange membrane in flow batteries, where water-induced high swelling leads to poor membrane stability. The thioether group has strong reactivity, and the polyaryl ether containing pyridine and thioether groups can provide a precisely controllable number of potential thioether crosslinking points. These thioether crosslinking points can be thermally or radiatively crosslinked to improve the swelling resistance and chemical stability of the membrane material, which is beneficial for further functionalization and modification of the polyaryl ether containing pyridine and thioether groups. Besides being used as membrane materials, polyarylethers containing pyridine and thioether groups have excellent mechanical strength, solubility, good film-forming properties, and excellent chemical stability. The polar pyridine and thioether groups can increase the polarity of the polyarylether molecular chain, thereby improving the cohesiveness and adhesion of the polymer. They have great application prospects in composite materials, paints, coatings, and other applications requiring high-temperature and high-performance materials.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: The first object of the present invention is to provide a polyarylene ether containing pyridine and thioether groups, said polyarylene ether having repeating structural units as shown in Formula I: .

[0008] Ar1 has the following chemical structural formula: or .

[0009] R1 is an alkyl or phenyl group.

[0010] Ar2 has the following chemical structural formula: or .

[0011] Where 0.01 < y < 0.99; positive integers from 50 to 1000 represent the degree of aggregation.

[0012] Furthermore, the alkyl group is a C1 to C7 alkyl group.

[0013] A second objective of this invention is to provide a method for preparing the above-mentioned polyarylene ethers containing pyridine and thioether groups, comprising the following steps: S1. Using bisphenol monomers containing pyridine groups, sulfur-containing bisphenol monomers, and aromatic dihalogen monomers as raw materials, and alkali, alkali metal, or alkaline earth metal salts as catalysts, a polymerization reaction is carried out in a solvent reaction system under the protection of a protective gas. Azeotropic dehydration is carried out during the polymerization reaction. After the reaction is completed, a polymer system is obtained.

[0014] S2. Add solvent to dilute the polymer system, add precipitant to precipitate, separate and dry to obtain polyarylether containing pyridine groups and thioether groups.

[0015] Furthermore, the alkali is at least one of lithium hydroxide, sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide, strontium hydroxide, and barium hydroxide; the salt of alkali metal or alkaline earth metal is at least one of lithium carbonate, sodium carbonate, potassium carbonate, cesium carbonate, magnesium carbonate, calcium carbonate, strontium carbonate, barium carbonate, sodium bicarbonate, potassium bicarbonate, magnesium bicarbonate, or calcium bicarbonate.

[0016] Furthermore, the polymerization reaction temperature is 50℃~300℃, and the reaction time is 0.5h~48h.

[0017] Furthermore, the azeotropic dehydrating agent is benzene, toluene, xylene, or chlorobenzene.

[0018] Furthermore, the precipitant is water, methanol, or ethanol.

[0019] Furthermore, the polar organic solvent is one or a mixture of two or more of N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, sulfolane, and dimethyl sulfoxide.

[0020] Furthermore, the protective gas is nitrogen or an inert gas.

[0021] A third objective of this invention is to provide the application of the aforementioned polyarylethers containing pyridine and thioether groups in separation membranes or ion exchange membranes.

[0022] The beneficial effects of this invention are compared with those of the prior art: The polyaryl ether containing pyridine and thioether groups provided by this invention possesses partial crystallization ability. This allows the diphenyl thioether structure in the resulting polymer molecular chain to impart flexibility, improving the molecular chain regularity and facilitating crystallization to obtain partially crystalline polymers. This overcomes the limitations of pyridine-containing polyaryl ethers in application. When used as separation membranes or ion exchange membranes, it can effectively suppress swelling caused by water or solvents, especially when used as an ion exchange membrane in flow batteries, where water-induced high swelling leads to poor membrane stability. The thioether group has strong reactivity, and the polyaryl ether containing pyridine and thioether groups can provide a precisely controllable number of potential thioether crosslinking points. These thioether crosslinking points can be thermally or radiatively crosslinked to improve the swelling resistance and chemical stability of the membrane material, which is beneficial for further functionalization and modification of the polyaryl ether containing pyridine and thioether groups.

[0023] Besides being used as membrane materials, polyarylethers containing pyridine and thioether groups have excellent mechanical strength, solubility, good film-forming properties, and excellent chemical stability. The polar pyridine and thioether groups can increase the polarity of the polyarylether molecular chain, thereby improving the cohesive force and adhesion of the polymer. They have great application prospects in composite materials, paints, coatings, and other applications requiring high-temperature and high-performance materials, meeting different functional requirements. Attached Figure Description

[0024] Figure 1 The polyaryl ethers with pyridine and thioether groups prepared in Examples 1 to 3 of this invention 1 H NMR spectrum Figure 1 (a) is 1 H NMR spectrum, (b) is a magnified view of (a).

[0025] Figure 2 The images show the XRD patterns of the polyarylene ethers with pyridine and thioether groups prepared in Examples 1 to 4 of this invention.

[0026] Figure 3The above are TGA and DSC images of the polyarylene ethers with pyridine and thioether groups prepared in Examples 1 to 4 of this invention. Figure 3 (a) is a TGA chart, and (b) is a DSC chart.

[0027] Figure 4 The infrared spectra of polyarylene ethers with pyridine and thioether groups prepared in Examples 1 to 4 of this invention are shown.

[0028] Figure 5 The tensile strength diagrams are for the polyarylene ether films with pyridine and thioether groups prepared in Examples 1 to 4 of this invention.

[0029] Figure 6 The swelling properties of the polyarylene ether films with pyridine and thioether groups prepared in Examples 1 to 4 of this invention and the polyarylene ether film prepared in Comparative Example 1 are shown in the diagram.

[0030] Figure 7 The water content of the polyarylene ether membranes with pyridine and thioether groups prepared in Examples 1 to 4 of this invention and the polyarylene ether membrane prepared in Comparative Example 1 are shown in the diagram.

[0031] Figure 8 This is a battery performance diagram of the polyarylene ether membrane with pyridine and thioether groups prepared in Example 4 of this invention. Figure 8 In the table, (a) represents the coulombic efficiency, (b) represents the voltage efficiency, and (c) represents the energy efficiency.

[0032] Figure 9 The battery cycle performance diagram shows the polyarylene ether membrane with pyridine and thioether groups prepared in Example 4 of this invention. Detailed Implementation

[0033] To enable those skilled in the art to better understand and implement the technical solutions of this invention, the invention is further described below with reference to specific embodiments. However, the embodiments are not intended to limit the invention. Unless otherwise specified, the following test methods and detection methods are conventional methods; unless otherwise specified, the reagents and raw materials are commercially available.

[0034] The present invention will now be described in detail through specific embodiments. These embodiments are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0035] This invention, from the perspective of molecular structure design, enables the diphenyl sulfide structure in the obtained polymer molecular chain to impart flexibility to the molecular chain, which can improve the regularity of the molecular chain and make it more conducive to crystallization to obtain partially crystalline polymers. It overcomes the limitations of polyarylethers containing pyridine groups in application. When used as a separation membrane or ion exchange membrane, it can effectively suppress the swelling of the membrane by water or solvents.

[0036] A polyaryl ether containing pyridine and thioether groups, the polyaryl ether having repeating structural units as shown in Formula I: .

[0037] Ar1 has the following chemical structural formula: or .

[0038] R1 is an alkyl or phenyl group.

[0039] Ar2 has the following chemical structural formula: or .

[0040] Where 0.01 < y < 0.99; n is a positive integer from 50 to 1000, representing the degree of aggregation.

[0041] In a preferred embodiment, the alkyl group is a C1 to C7 alkyl group.

[0042] In a preferred embodiment, n is 80 to 800, more preferably 100 to 500.

[0043] The preparation method of the above-mentioned polyarylene ethers containing pyridine and thioether groups includes the following steps: Using pyridine-bisphenol monomers, 4,4'-dihydroxydiphenyl sulfide monomers, and dihalogen monomer X-Ar-X as raw materials, and alkali, alkali metal, or alkaline earth metal salts as catalysts, the mixture is prepared via solution polycondensation in an aprotic polar solvent. The reaction route equation is as follows:

[0044] .

[0045] More specifically, the preparation process of this polymer is as follows: using bisphenol monomers containing pyridine groups, sulfur-containing bisphenol monomers, and aromatic dihalogen monomers as raw materials, a polymerization reaction is carried out at a certain temperature under inert gas protection. Azeotropic dehydration is carried out during the reaction. After the reaction is completed, a solvent is added to the system for dilution. The polymer solution is poured into a precipitant, and the polymer is precipitated under stirring. The polymer is then separated by filtration to obtain the polymer. The polymer is filtered and dried to obtain polyarylethers containing pyridine groups and thioether groups. Finally, the polymer is dissolved in a polar organic solvent to prepare a film.

[0046] The diphenyl sulfide structure in the polymer molecular chain obtained by this invention endows the molecular chain with flexibility, which can improve the regularity of the molecular chain and is more conducive to crystallization to obtain partially crystalline polymers. This overcomes the application limitations of polyaryl ethers containing pyridine groups. When used as separation membranes or ion exchange membranes, it can effectively suppress the swelling of the membrane by water or solvents, especially when used as an ion exchange membrane in flow batteries, where water-induced high swelling leads to poor membrane stability. The sulfide group has strong reactivity, and polyaryl ethers containing pyridine and sulfide groups can provide a precise and controllable number of potential sulfide crosslinking points. These sulfide crosslinking points can be thermally or radiatively crosslinked to improve the swelling resistance and chemical stability of the membrane material, which is beneficial for further functionalization of polyaryl ethers containing pyridine and sulfide groups and modification of products. Besides being used as membrane materials, polyarylethers containing pyridine and thioether groups have excellent mechanical strength, solubility, good film-forming properties, and excellent chemical stability. The polar pyridine and thioether groups can increase the polarity of the polyarylether molecular chain, thereby improving the cohesiveness and adhesion of the polymer. They have great application prospects in composite materials, paints, coatings, and other applications requiring high-temperature and high-performance materials.

[0047] The following specific examples will provide further explanation.

[0048] Example 1 This embodiment provides a polyarylene ether containing pyridine and thioether groups, named PySPEK-73, and the specific preparation method is as follows: In a 100 mL three-necked flask, 0.007 mol of pyridine bisphenol monomer, 0.003 mol of 4,4'-dihydroxydiphenyl sulfide, 0.01 mol of 4,4'-difluorobenzophenone, and 0.012 mol of anhydrous potassium carbonate were added and dissolved in 5 mL of N,N-dimethylacetamide. 3 mL of toluene solution was added as a dehydrating agent. The flask was equipped with a mechanical stirrer, condenser, water separator, and nitrogen purging tube. The temperature was raised to 140 °C and refluxed for 4 h, then raised to 160 °C and reacted for 6 h. The reaction was stopped, and the reaction solution was diluted with solvent and poured into distilled water. The mixture was filtered to obtain the crude product. The crude product was boiled in distilled water for 4 h, filtered, and dried to obtain a polyarylene ether containing pyridine and thioether groups, with a yield >98%.

[0049] The synthesis reaction formula is shown below: .

[0050] Where n is 200.

[0051] A membrane was prepared by dissolving PySPEK-73, a polyaryl ether containing pyridine and thioether groups, in N-methylpyrrolidone solvent. After pre-swelling with phosphoric acid (50 wt.%), the membrane was stored in 3 M H₂SO₄. The membrane was sandwiched between two carbon felt electrodes (effective area 5 cm²). 2 A VRFB is formed by placing the sample between two graphite plates. The electrolyte is 20 mL of 1.5 M V solution in 3 M H2SO4. 2+ / V 3+ 20 mL of 1.5 M VO in 3 M H2SO4 2+ / VO 2+ The electrolyte was delivered by a peristaltic pump, with both positive and negative electrolyte flow rates at 25 mL / min. Battery testing was conducted at 25°C using a Neware 5V / 3A battery testing system. The charge and discharge cutoff voltages were 1.65V and 0.8V, respectively.

[0052] Example 2 This embodiment provides a polyarylene ether containing pyridine and thioether groups, named PySPEK-64, and the specific preparation method is as follows: In a 100 mL three-necked flask, 0.006 mol of pyridine bisphenol monomer, 0.003 mol of 4,4'-dihydroxydiphenyl sulfide, 0.01 mol of 4,4'-difluorobenzophenone, and 0.012 mol of anhydrous potassium carbonate were added and dissolved in 5 mL of dimethyl sulfoxide. 3 mL of toluene solution was added as a dehydrating agent. The flask was equipped with a mechanical stirrer, condenser, water separator, and nitrogen purging tube. The temperature was raised to 140 °C and refluxed for 4 h, then raised to 160 °C and reacted for 6 h. The reaction was stopped, and the reaction solution was diluted with solvent and poured into distilled water. The mixture was filtered to obtain the crude product. The crude product was boiled in distilled water for 4 h, filtered, and dried to obtain a polyarylene ether containing pyridine and sulfide groups, with a yield >98%.

[0053] The synthesis reaction formula is shown below: .

[0054] Where n is 230.

[0055] A membrane was prepared by dissolving PySPEK-64, a polyaryl ether containing pyridine and thioether groups, in N-methylpyrrolidone solvent. After pre-swelling with phosphoric acid (50 wt.%), the membrane was stored in 3 M H₂SO₄. The membrane was sandwiched between two carbon felt electrodes (effective area 5 cm²). 2 A VRFB is formed by placing the sample between two graphite plates. The electrolyte is 20 mL of 1.5 M V solution in 3 M H2SO4. 2+ / V 3+ 20 mL of 1.5 M VO in 3 M H2SO42+ / VO 2+ The electrolyte was delivered by a peristaltic pump, with both positive and negative electrolyte flow rates at 25 mL / min. Battery testing was conducted at 25°C using a Neware 5V / 3A battery testing system. The charge and discharge cutoff voltages were 1.65V and 0.8V, respectively.

[0056] Example 3 This embodiment provides a polyarylene ether containing pyridine and thioether groups, named PySPEK-55, and the specific preparation method is as follows: In a 100 mL three-necked flask, 0.005 mol of pyridine bisphenol monomer, 0.005 mol of 4,4'-dihydroxydiphenyl sulfide, 0.01 mol of 4,4'-difluorobenzophenone, and 0.014 mol of anhydrous potassium carbonate were added and dissolved in 5 mL of sulfolane. 4 mL of toluene solution was added as a dehydrating agent. The flask was equipped with a mechanical stirrer, condenser, water separator, and nitrogen purging tube. The temperature was raised to 140 °C and refluxed for 4 h, then raised to 160 °C and reacted for 6 h. The reaction was stopped, and the reaction solution was diluted with solvent and poured into distilled water. The solution was filtered to obtain the crude product. The crude product was boiled in distilled water for 4 h, filtered, and dried to obtain a polyarylene ether containing pyridine and thioether groups, with a yield >98%.

[0057] The synthesis reaction formula is shown below: .

[0058] Where n is 2^10.

[0059] A membrane was prepared by dissolving PySPEK-55, a polyaryl ether containing pyridine and thioether groups, in N-methylpyrrolidone solvent. After pre-swelling with phosphoric acid (50 wt.%), the membrane was stored in 3 M H₂SO₄. The membrane was sandwiched between two carbon felt electrodes (effective area 5 cm²). 2 A VRFB is formed by placing the sample between two graphite plates. The electrolyte is 20 mL of 1.5 M V solution in 3 M H2SO4. 2+ / V 3+ 20 mL of 1.5 M VO in 3 M H2SO4 2+ / VO 2+ The electrolyte was delivered by a peristaltic pump, with both positive and negative electrolyte flow rates at 25 mL / min. Battery testing was conducted at 25°C using a Neware 5V / 3A battery testing system. The charge and discharge cutoff voltages were 1.65V and 0.8V, respectively.

[0060] Example 4 This embodiment provides a polyarylene ether containing pyridine and thioether groups, named PySPEK-37, and the specific preparation method is as follows: In a 100 mL three-necked flask, 0.003 mol of pyridine bisphenol monomer, 0.007 mol of 4,4'-dihydroxydiphenyl sulfide, 0.01 mol of 4,4'-difluorobenzophenone, and 0.014 mol of anhydrous potassium carbonate were added. The monomers were dissolved in 5 mL of N-methylpyrrolidone, and 4 mL of toluene solution was added as a dehydrating agent. The flask was equipped with a mechanical stirrer, a condenser, a water separator, and a nitrogen purging tube. The temperature was raised to 140 °C and refluxed for 4 h, then raised to 180 °C and reacted for 8 h. The reaction was stopped, and the reaction solution was diluted with solvent and poured into distilled water. The solution was filtered to obtain a crude product. The crude product was boiled in distilled water for 4 h, filtered, and dried to obtain a polyarylene ether containing pyridine and sulfide groups, with a yield >98%.

[0061] The synthesis reaction formula is shown below: .

[0062] Where n is 250.

[0063] A membrane was prepared by dissolving PySPEK-37, a polyaryl ether containing pyridine and thioether groups, in N-methylpyrrolidone solvent. After pre-swelling with phosphoric acid (50 wt.%), the membrane was stored in 3 M H₂SO₄. The membrane was sandwiched between two carbon felt electrodes (effective area 5 cm²). 2 A VRFB is formed by placing the sample between two graphite plates. The electrolyte is 20 mL of 1.5 M V solution in 3 M H2SO4. 2+ / V 3+ 20 mL of 1.5 M VO in 3 M H2SO4 2+ / VO 2+ The electrolyte was delivered by a peristaltic pump, with both positive and negative electrolyte flow rates at 25 mL / min. Battery testing was conducted at 25°C using a Neware 5V / 3A battery testing system. The charge and discharge cutoff voltages were 1.65V and 0.8V, respectively.

[0064] Comparative Example 1 This comparative example provides a method for preparing a polyarylene ether without a thioether group, named PyEMeK. The specific preparation method is as follows: In a 100 mL three-necked flask, 0.01 mol of pyridine bisphenol monomer, 0.01 mol of 4,4'-difluorobenzophenone, and 0.012 mol of anhydrous potassium carbonate were added and dissolved in 5 mL of N,N-dimethylacetamide. 3 mL of toluene solution was added as a dehydrating agent. The flask was equipped with a mechanical stirrer, condenser, water separator, and nitrogen purging tube. The temperature was raised to 140 °C and refluxed for 4 h, then raised to 160 °C and reacted for 6 h. The reaction was stopped, and the reaction solution was diluted with solvent and poured into distilled water. The mixture was filtered to obtain the crude product. The crude product was boiled in distilled water for 4 h, filtered, and dried to obtain the polyarylene ether polymer with a yield >98%.

[0065] The synthesis reaction formula is shown below: .

[0066] Where n is 200.

[0067] A membrane was prepared by dissolving the polyarylene ether polymer PyEMeK in a solvent, pre-swelling it with phosphoric acid (50 wt.%), and then storing it in 3 M H₂SO₄. The membrane was sandwiched between two carbon felt electrodes (effective area 5 cm²). 2 A VRFB is formed by placing the sample between two graphite plates. The electrolyte is 20 mL of 1.5 M V solution in 3 M H2SO4. 2+ / V 3+ 20 mL of 1.5 M VO in 3 M H2SO4 2+ / VO 2+ The electrolyte was delivered by a peristaltic pump, with both positive and negative electrolyte flow rates at 25 mL / min. Battery testing was conducted at 25°C using a Neware 5V / 3A battery testing system. The charge and discharge cutoff voltages were 1.65V and 0.8V, respectively.

[0068] The performance of the polyarylene ether polymers prepared in Examples 1 to 4 and Comparative Example 1 was tested, as follows: Figure 1 The polyaryl ethers with pyridine and thioether groups prepared in Examples 1 to 3 of this invention 1 H NMR spectrum Figure 1 (a) is 1 The 1H NMR spectrum, (b) is a magnified view of (a). From 1 As can be seen from the H NMR spectra, the polyarylether structures with pyridine and thioether groups prepared in Examples 1 to 3 have a good correspondence with the NMR signals, proving that the polyarylether polymers containing pyridine and thioether groups were successfully prepared.

[0069] Figure 2The images show the XRD patterns of the polyaryl ethers with pyridine and thioether groups prepared in Examples 1 to 4 of this invention. Figure 2 As shown, a polyarylether polymer containing pyridine and thioether groups has a crystalline structure, and the higher the proportion of thioether groups, the higher the crystallization peak, for example, PySPEK-37.

[0070] Figure 3 The above are TGA and DSC images of the polyarylene ethers with pyridine and thioether groups prepared in Examples 1 to 4 of this invention. Figure 3 In the image, (a) is a TGA chart and (b) is a DSC chart. Figure 3 As shown, the polyarylether polymers containing pyridine and thioether groups in Examples 1 to 4 exhibit good thermal stability.

[0071] Figure 4 The images show the infrared spectra of the polyaryl ethers with pyridine and thioether groups prepared in Examples 1 to 4 of this invention. Figure 4 As shown, a polyarylene ether membrane containing pyridine and thioether groups has been successfully prepared.

[0072] Figure 5 This is a tensile strength diagram of the polyarylene ether films with pyridine and thioether groups prepared in Examples 1 to 4 of this invention. Figure 5 As shown, the tensile strength of the membrane gradually increases with the increase of sulfide groups. This is because the higher the sulfide content, the higher the crystal content of the membrane, which will improve the mechanical strength of the membrane.

[0073] Figure 6 The swelling properties of the polyarylene ether films with pyridine and thioether groups prepared in Examples 1 to 4 of this invention and the polyarylene ether film prepared in Comparative Example 1 are shown in the diagram. Figure 6 As shown, it can be seen that the membrane's ability to suppress swelling is enhanced with the increase of thioether groups.

[0074] Figure 7 The figures show the water content of the polyarylene ether membranes with pyridine and thioether groups prepared in Examples 1 to 4 of this invention, and the polyarylene ether membrane prepared in Comparative Example 1. Figure 7 As shown, it can be seen that the water content of the membrane without thioether groups (PyEMeK prepared in Comparative Example 1) is significantly higher than that of the membrane with thioether groups in the examples.

[0075] Figure 8 This is a battery performance diagram of the polyarylene ether membrane with pyridine and thioether groups prepared in Example 4 of this invention. Figure 8In the table, (a) represents the coulombic efficiency, (b) represents the voltage efficiency, and (c) represents the energy efficiency. PySPEK-37-90, PySPEK-37-110, and PySPEK-37-130 represent the swelling treatment temperatures at 90℃, 110℃, and 130℃, respectively. Figure 8 As shown, the PySPEK-37 film with high crystallinity exhibits good battery performance.

[0076] Figure 9 This is a battery cycle performance diagram of the polyarylene ether membrane with pyridine and thioether groups prepared in Example 4 of the present invention. Figure 9 As shown, the highly crystallinity PySPEK-37 film can withstand high current densities of 200 mA / cm². -2 It can maintain stable battery performance for 1500 cycles and has excellent chemical stability.

[0077] The above description is merely a preferred embodiment of the present invention, and the specific embodiments described above are not intended to limit the present invention. Various modifications and variations can be made within the scope of the technical concept of the present invention. All refinements, modifications, or equivalent substitutions made by those skilled in the art based on the above description are within the scope of protection of the present invention.

Claims

1. A polyarylene ether containing a pyridine group and a thioether group, characterized in that, The polyarylether has a repeating structural unit as shown in Formula I: ； wherein Ar1 has a chemical structure as shown in Formula II: or ; R1 is an alkyl group or a phenyl group; Ar2 has a chemical structure as shown in Formula III: or ; wherein 0.01 < y < 0.99; n is a positive integer of 50-1000, representing the degree of polymerization.

2. The polyarylene ether containing pyridyl groups and thioether groups according to claim 1, characterized in that, The alkyl group is a C1-C7 alkyl group.

3. A process for the preparation of a polyarylene ether containing pyridine groups and thioether groups according to claim 1 or 2, characterized in that, The method comprises the following steps: The polymerization reaction is carried out in a solvent reaction system under the protection of a protective gas, and azeotropic dehydration is carried out during the polymerization reaction. The polymer system is diluted by adding a solvent, and a precipitant is added to precipitate, separate and dry to obtain the polyarylether containing a pyridine group and a thioether group.

4. The method for producing a polyarylene ether containing a pyridyl group and a thioether group according to claim 3, characterized by, The base is at least one of lithium hydroxide, sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide, strontium hydroxide, and barium hydroxide; and the salt of an alkali metal or an alkaline earth metal is at least one of lithium carbonate, sodium carbonate, potassium carbonate, cesium carbonate, magnesium carbonate, calcium carbonate, strontium carbonate, barium carbonate, sodium bicarbonate, potassium bicarbonate, magnesium bicarbonate, or calcium bicarbonate.

5. The method for preparing the polyarylene ether containing pyridine and thioether groups according to claim 3, characterized in that, The temperature of the polymerization reaction is 50-300°C, and the reaction time is 0.5-48 hours.

6. The method for preparing the polyarylene ether containing pyridine and thioether groups according to claim 3, characterized in that, The azeotropic dehydration agent is benzene, toluene, xylene, or chlorobenzene.

7. The method for preparing the polyarylene ether containing pyridine and thioether groups according to claim 3, characterized in that, The precipitant is water, methanol, or ethanol.

8. The method for preparing the polyarylene ether containing pyridine and thioether groups according to claim 3, characterized in that, The polar organic solvent is one of N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, sulfolane, or dimethyl sulfoxide, or a mixture of two or more thereof.

9. The method for preparing the polyarylether containing a pyridine group and a thioether group according to claim 3, wherein the protective gas is nitrogen or an inert gas.

10. Use of the polyarylether containing a pyridine group and a thioether group according to claim 1 or 2 in a separation membrane or an ion exchange membrane.

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