Azulene-based polysulfone anion exchange membrane, preparation method and application thereof

Abstract

The application discloses a kind of containing azulene group polysulfone anion exchange membrane and preparation method and application thereof, belong to membrane technical field.The application is prepared by polymerization and quaternary ammonium reaction, a series of novel alkali-resistant, high-temperature-resistant basic anion exchange membrane.The polysulfone and its crosslinked polymer have high mechanical strength and thermal stability, which greatly reduces the water absorption and expansion ratio of anion exchange membrane, thereby improving the dimensional stability;Meanwhile, high stability cation group and nucleophilic azulene group functional group increase its basic stability.Its high OH ‑ The high OH conductivity, basic stability and high mechanical strength show that the azulene group polysulfone anion exchange membrane of the application can be used as an anion exchange membrane material for basic fuel cells and basic electrolytic cells.

Description

Technical Field

[0001] This invention belongs to the field of membrane technology, specifically relating to an azulene polysulfone anion exchange membrane, its preparation method, and its application. Background Technology

[0002] Over the past century, global energy demand has continued to grow rapidly worldwide due to global development and population growth. Developing clean and efficient hydrogen energy aligns with the energy strategies of "carbon peaking" and "carbon neutrality," contributing to sustainable human development. Green hydrogen can be produced through water electrolysis technology driven by surplus solar and wind power generation, with fuel cells representing a primary application of hydrogen energy. Currently, proton exchange membrane fuel cells and acidic electrolyzers, operating under acidic conditions, require precious metal catalysts and expensive proton exchange membranes, resulting in prohibitively high costs for hydrogen production and utilization, significantly hindering industrial development. Anion exchange membrane fuel cells and alkaline water electrolysis technology, which can use low-alkaline electrolytes and non-precious metal catalysts, significantly reduce operating costs and have therefore attracted widespread attention.

[0003] Anion exchange membranes (AEMs) are a key component of anion exchange membrane fuel cells and alkaline electrolyzers. Preparing anion exchange membranes with high hydroxide conductivity and stable chemical properties is crucial for achieving high power density and long-term durability in anion exchange membrane fuel cells and alkaline electrolyzers. Anion exchange membranes consist of a polymer backbone, cationic groups, and migratable ions. The polymer backbone structure and the properties of the cationic groups directly determine the performance of the AEM. Current research on AEMs still faces the following technical bottlenecks: (1) Because the radius of OH- is larger than that of H+, the OH- in the AEM... - The conductivity is only that of H in a proton exchange membrane under the same conditions. + The conductivity is 20% to 33%. The most direct way to improve conductivity is to increase ion exchange capacity (IEC). Increasing IEC means introducing more hydrophilic cationic groups, which leads to increased water absorption and swelling of the membrane, resulting in a decrease in membrane mechanical properties. Therefore, solving the "trade-off" effect between membrane ionic conductivity and dimensional stability is crucial for the development of AEM. (2) Under hot alkaline working conditions, the polymer backbone and cationic groups are susceptible to nucleophilic OH groups. - The attack of alkali leads to complex degradation reactions in the main chain structure and cationic groups, resulting in decreased membrane performance and even reduced service life of the AEM. Therefore, improving the alkali stability of AEM and extending its service life is another urgent scientific problem to be solved. Summary of the Invention

[0004] This invention provides an azurite-based polysulfone anion exchange membrane, characterized in that the raw material of the azurite-based polysulfone anion exchange membrane is or contains an azurite-based polysulfone polymer, and its structure is shown in Formula 1:

[0005]

[0006] Wherein, R1 represents different types of cationic groups, R2 is a copolymer or branched monomer, a and b represent the molar percentage of the two repeating units, the value of a is between 0 and 100 (the sum of the a values ​​of the cross-linked polymers is between 0 and 100), the value of b is between 0 and 100, and a + b = 100 (the value of a is preferably 15-50, more preferably 25).

[0007] Preferably, in conjunction with the first aspect, R1 is at least one of the following structures:

[0008]

[0009] Where n is an integer greater than or equal to 0.

[0010] Preferably, in conjunction with the first aspect, R2 is at least one of the following structures:

[0011]

[0012] The present invention also provides a method for preparing the azulene polysulfone anion exchange membrane, the method comprising the following steps:

[0013] (1) Synthesis of azulene polysulfone precursor polymer: Under alkaline catalytic conditions, diphenyl sulfone monomer, azulene monomer, and monomer R2 were dissolved in organic solvents α and β in a certain proportion, and a condensation reaction was carried out to generate azulene polysulfone polymer (PSU-Az). PSU-Az polymer can be synthesized by three methods: DMAc / K2CO3, DMSO / NaOH, and DMSO / KOH. The DMAc / K2CO3 method is a one-step method for preparing the polymer: First, under N2 protection, diphenol monomer, azulene monomer, K2CO3, DMAc, and toluene were added to a dry three-necked flask in a certain proportion. Then, the mixture was heated under reflux at 140℃ for 8 h, and toluene and water were removed by azeotropic distillation. After heating the mixture at 160℃ for 12 h, a viscous polymer solution was obtained. After cooling to room temperature, the viscous polymer solution was diluted with THF. The diluted solution was then poured into water to obtain a white fibrous polymer, which was then vacuum dried at 120°C for 24 hours to obtain the target product. The DMSO / KOH and DMSO / NaOH methods employ a two-step process to prepare the polymer. The process is as follows: Under N2 protection, diphenol monomer, K2CO3, DMAc, and toluene were added to a dry three-necked flask in a specific ratio and refluxed at 140°C for 6 hours. Water was removed by azeotropic distillation. Then, by controlling the removal of toluene from the reaction mixture, the temperature was slowly raised to 160°C. Subsequently, azulene monomer was added to the system, and the reaction was carried out at 160°C for approximately 1 hour to obtain a viscous polymer solution. The following steps are the same as those in the DMAc / K2CO3 method.

[0014] The structure is shown in Equation II:

[0015]

[0016] Wherein, R1 represents different types of cationic groups, R2 is a copolymer or branched monomer, a and b represent the percentage of molar content of two repeating units, the value of a is between 0 and 100 (the sum of the a values ​​of the cross-linked polymers is between 0 and 100), the value of b is between 0 and 100 (the sum of the b values ​​of the cross-linked polymers is between 0 and 100, and a + b = 100 (the a value is preferably 15-50, more preferably 20-25); (2) Synthesis of cationic azulene polysulfone: The azulene polysulfone obtained in step 1 is dissolved in an organic solvent, potassium carbonate and iodomethane are added, and the reaction is stirred at room temperature in the dark for 24 h. Ethyl acetate is added to the resulting viscous solution. After filtering the precipitate, it is washed three times with water, and the solvent is evaporated by vacuum drying to obtain cationic azulene polysulfone;

[0017] (3) Preparation of azulene polysulfone anion exchange membrane: The cationized azulene polysulfone obtained in step 2 was dissolved in an organic solvent, stirred at room temperature and filtered. The filtrate was cast onto a clean glass plate, residual solvent was removed, and then the membrane was carefully peeled off the glass plate to obtain Cl. - Type membrane, then Cl - The membrane was placed in KOH solution for ion exchange to obtain OH-. - The membrane was then washed with degassed deionized water under an inert atmosphere to obtain an azulene polysulfone anion exchange membrane.

[0018] In a preferred embodiment of the present invention, the molar ratio of azulene monomer to diphenol monomer in step (1) is 1:0.9-1.5.

[0019] In another preferred embodiment of the present invention, in step (1), the volume ratio of solvent α and β is 1:0.8-1.2.

[0020] In another preferred embodiment of the present invention, in step (1), the organic solvent α is selected from at least one of DMSO, DMAc, DMF, or NMP.

[0021] In another preferred embodiment of the present invention, in step (1), the organic solvent β is selected from at least one of benzene, toluene, o-xylene, m-xylene, p-xylene, p-trimethylene, and m-trimethylene.

[0022] In another preferred embodiment of the present invention, in step (2), the organic solvent is selected from at least one of acetonitrile, tetrahydrofuran, N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylacetamide, N,N-dimethylformamide or sulfolane.

[0023] The present invention also provides an azulene polysulfone anion exchange membrane prepared by the method described above.

[0024] The present invention also provides an application of the azulene polysulfone anion exchange membrane as described above in the preparation of fuel cells or alkaline electrolyzers.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] This invention synthesizes an azulene polysulfone polymer, which, through polymerization and quaternization, forms a novel basic anion exchange membrane. The polysulfone structure generates high mechanical strength, significantly reducing the water absorption and swelling rate of the anion exchange membrane, thereby improving dimensional stability. Simultaneously, the highly stable cationic nucleophilic azulene group enhances its basic stability. Its high OH... -The conductivity, alkalinity stability, and high mechanical strength indicate that the azurite polysulfone anion exchange membrane obtained in this invention can be used as anion exchange membrane material for alkaline fuel cells and alkaline electrolyzers.

[0027] The azulene polybenzimidazole anion exchange membrane provided by this invention exhibits high OH content. - With its high electrical conductivity, alkaline stability, and high mechanical strength, it can be used as an anion exchange membrane material for alkaline fuel cells and alkaline electrolyzers.

[0028] Through optimization, the azulene polysulfone anion exchange membrane of the present invention exhibits high OH... - Conductivity (at 80℃, OH) - Conductivity > 100 mS cm -1 It exhibits high mechanical strength (tensile strength >35MPa, elongation at break >10%), high dimensional stability, good processing performance, and excellent alkaline stability (>500h) in 1M KOH at 80℃.

[0029] Compared to other types of branched poly(aryl-piperidine) anion exchange membranes, the strong dipole moment azulene groups and sulfur-containing backbone in its molecular structure promote the formation of a stronger hydrogen bond network, thus facilitating the OH- ion exchange. - High-speed transport; the introduction of nucleophilic azurite groups makes the structure less susceptible to OH groups. - The attack enhances its alkaline stability; the formation of branched structures causes the molecular chains to become entangled, enhancing its mechanical properties. Attached Figure Description

[0030] Figure 1 Synthetic pathway diagram of 6-6'-biazine crosslinked poly(6-piperidinazine sulfone) (PSU-Az-BiAz) provided in this application

[0031] Figure 2 The synthetic route diagram for poly(6-piperidinium azylbenzene sulfone) (PSU-Az-Pd) provided in this application is shown.

[0032] Figure 3 The synthetic route diagram of poly(6-piperidinium azyl sulfone) (PSU-Az-Pr) provided in this application.

[0033] Figure 4 The commercial product FAA3-50OH, an azulene polysulfone anion exchange membrane prepared in Examples 1, 2, and 3. - Conductivity test results.

[0034] Figure 5 The results of water electrolysis tests of the azurite polysulfone anion exchange membranes prepared for Examples 1, 2 and 3 and the commercial product FAA3-50 anion exchange membrane.

[0035] Figure 6The water absorption test results of the commercial product FAA3-50, azulene polysulfone anion exchange membrane prepared in Examples 1, 2 and 3.

[0036] Figure 7 The swelling rate test results of the azulene polysulfone anion exchange membrane FAA3-50 commercial product prepared in Examples 1, 2 and 3. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be regarded as limitations on this application. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0038] In the following description, references to "some embodiments" refer to a subset of all possible embodiments. However, it is understood that "some embodiments" may be the same or different subsets of all possible embodiments and may be combined with each other without conflict. Unless otherwise defined, all technical and scientific terms used in the embodiments of this application have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiments of this application pertain. The terminology used in the embodiments of this application is for the purpose of describing the embodiments of this application only and is not intended to limit the application.

[0039] In the following description of this embodiment, the terms "including", "comprising", "having", and "containing" are all open-ended terms, meaning that they include but are not limited to.

[0040] It should be noted that all raw materials / reagents in the embodiments of this application can be purchased on the market or prepared according to conventional methods known to those skilled in the art; the term "and / or" in the embodiments of this application is only used to describe the relationship between related objects, indicating that there can be three relationships. For example, A and / or B means three cases: A exists alone, B exists alone, and A and B exist simultaneously. A and B can be singular or plural. The character " / " generally indicates that the related objects before and after are in an "or" relationship.

[0041] In the following description of this embodiment, the term "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0042] Those skilled in the art should understand that, in the following description of the embodiments of this application, the sequence of numbers does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0043] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms "a" and "the" as used in the embodiments of this application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0044] Those skilled in the art will understand that the numerical ranges in the embodiments of this application should be understood to specifically disclose each intermediate value between the upper and lower limits of the range. Each smaller range between any stated value and an intermediate value within the stated range, as well as any other stated value or an intermediate value within the stated range, is also included in this application. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0045] Unless otherwise stated, the technical / scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art described herein. While this application describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may be used in embodiments or test examples of this application. All references to this specification are generally incorporated herein by reference to disclose and describe methods and / or materials associated with said references. In the event of any conflict with any incorporated references, the content of this application shall prevail.

[0046] It should be noted that all raw materials and / or reagents in the embodiments of this application were purchased on the market or prepared according to conventional methods known to those skilled in the art.

[0047] The following are the testing methods used in the examples:

[0048] Performance testing:

[0049] The equipment and testing methods involved in the embodiments:

[0050] Ion exchange capacity (IEC) test method: Take Cl from polyazine sulfide polymer - Type or Br -The membrane was dried in a vacuum oven at 75°C and its mass was recorded. The dried membrane was then immersed in 25 mL of 0.2 M NaNO3 solution for 6 hours, repeated three times, and the NaNO3 solution after ion exchange was collected. Potassium chromate solution was added to this solution, and titration was performed with 0.01 M AgNO3 standard solution. The titration was complete when a brick-red precipitate appeared and did not disappear after shaking. The volume of AgNO3 solution consumed was recorded. The product of the AgNO3 solution concentration and volume, divided by the mass of the dried membrane, is the IEC (interval between concentration and volume).

[0051] Conductivity testing: The electrochemical workstation used was a CHI660E manufactured by Shanghai Chenhua Instrument Co., Ltd. The electrochemical impedance spectroscopy (EIS) method was employed to test the membrane conductivity at different temperatures. The measured potential amplitude was 10 mV. To minimize the error caused by contact resistance, the resistance measured was the in-plane resistance of the membrane sample. In the experiment, the membrane was cut into 40 mm × 10 mm pieces, placed in a fixture, and the fixture was placed in pure water. The test temperature ranged from 30℃ to 80℃, with membrane resistance measured every 10℃. The membrane was kept at this temperature for 1 hour before each test. Finally, the ionic conductivity σ of the sample was calculated using the formula: σ = l / (wdR), where l is the length of the membrane between electrodes (cm), w is the width of the membrane (cm), d is the thickness of the membrane (μm), and R is the measured membrane resistance (mΩ).

[0052] Water absorption rate test: The membrane was immersed in 1M KOH solution at a specific temperature for 6 hours (repeated four times), and the ion exchange was OH-. - Form. Rinse several times with deionized water to remove residual KOH. After wiping away excess water from the surface, measure the wet mass (W) of the membrane. wet,OH Then use formula (1) to calculate the water absorption rate (WU):

[0053] WU(%) = (W wet,OH -W dry,OH ) / W dry,OH × 100% (1)

[0054] Expansion Rate (SR) Measurement: Based on wet film (x wet ) and dry film (x dry The linear size difference between PAP films is determined and calculated according to formula (2):

[0055] SR(%) = (x wet -x dry xdry × 100% (2)

[0056] Alkaline fuel cell performance testing: The instrument used was a Scribner Associates Co., Ltd., USA, model 850e multi-range fuel cell testing system, tested in current mode. The test conditions were complete humidification with H2 and O2, test temperature 60℃, 80℃, and H2 and O2 flow rate 200mL / min.

[0057] Anion exchange membrane water electrolysis performance test: Anode is loaded with IrO2 (1 mg / cm³) 2 The titanium felt is loaded with Pt / C (1 mg / cm³) as the cathode. 2 The carbon paper has an electrode area of ​​4 cm². 2 An MEA electrolytic cell was assembled using 1M KOH as the electrolyte, with a circulation rate of 20 mL / min and a test temperature of 60℃. A CHI660e instrument was used to perform a 0-2.5V linear voltammetric scan on the electrolytic cell.

[0058] Tensile strength test: The dry film sample of 5×0.5cm (length×width) was tested using an Instron M3300 electronic universal testing machine at a tensile rate of 5mm / min.

[0059] Alkali stability test: The prepared anion exchange membrane was immersed in NaOH solutions of different temperatures and concentrations, and its conductivity was measured at the same time. The alkali stability was analyzed by the change in the conductivity of the electrolyte membrane.

[0060] In a first aspect, embodiments of this application provide an azulene polysulfone anion exchange membrane, wherein the azulene polysulfone anion exchange membrane contains an azulene polysulfone polymer and has the following structure:

[0061]

[0062]

[0063] Wherein, R1 represents different types of cationic groups, R2 is a copolymer or branched monomer, a and b represent the percentage of molar content of the two repeating units, the value of a is between 0 and 100 (the sum of the a values ​​of the cross-linked polymers is between 0 and 100), the value of b is between 0 and 100 (the sum of the b values ​​of the cross-linked polymers is between 0 and 100, and a + b = 100 (the value of a is preferably 15-50, more preferably 20-25);

[0064] The azulene polysulfone anion exchange membrane provided in this application is a basic anion exchange membrane prepared by polymerization and quaternization. The strong dipole moment azulene groups and sulfur-containing backbone promote the formation of a strengthened hydrogen bond network, thus enhancing the OH- ion exchange capacity. -High-speed transport; the branched structure generates high mechanical strength, greatly reducing the water absorption and swelling rate of the anion exchange membrane, thereby improving dimensional stability; at the same time, the highly stable cationic groups and nucleophilic azurite groups increase its basic stability, and its high OH... - The conductivity, alkalinity stability, and high mechanical strength indicate that the polyazine sulfide anion exchange membrane prepared in this application can be used as anion exchange membrane material for alkaline fuel cells and alkaline electrolyzers.

[0065] In specific embodiments, R1 in this application is preferably one of the following structures:

[0066]

[0067] Where n is an integer greater than or equal to 0.

[0068] In a specific embodiment, R2 in this application is preferably one of the following structures:

[0069]

[0070] Secondly, embodiments of this application provide a method for preparing the azulene polysulfone anion exchange membrane described in the first aspect, the method comprising:

[0071] (1) Preparation of azulene polysulfone precursor:

[0072] The diphenol monomer, azulene monomer, and branched monomer were placed in a reaction vessel and dissolved in a first mixed organic solvent. The mixture was rapidly heated and reacted for a period of time. Water was removed by distillation. After the reaction, the solid product was washed, dried, and collected. The product was dissolved in a second organic solvent, potassium carbonate and iodomethane were added, and the mixture was reacted in the dark. Ethyl acetate was added, and the mixture was purified. The azulene polysulfone polymer was then collected.

[0073] (2) Preparation of azulene polysulfone anion exchange membrane:

[0074] Dissolve the cationic azulene polysulfone in a third organic solvent and collect I. - Type I thin film, making the I - Ion exchange is performed on a thin film to obtain OH-. - After purification, the azulene polysulfone anion exchange membrane was collected.

[0075] It should be noted that the azulene polysulfone precursor in the embodiments of this application is prepared by the following method: first, azulene monomer, branched monomer and diphenol monomer are placed in a reaction vessel in a certain proportion and dissolved in a first mixed organic solvent to obtain a mixed solution. The mixed solution is rapidly heated and reacted for a certain time. Then, water is removed by distillation and the reaction continues. After the reaction is completed, the obtained solid product is collected. The polymer solid is washed with deionized water and ethanol and dried to obtain azulene polysulfone.

[0076] It should be noted that the collection of azulene polysulfone polymer in the embodiments of this application includes: filtering to obtain solid polymer, washing three times with deionized water, washing once with anhydrous ethanol, and vacuum drying.

[0077] This application does not specify particular drying conditions, as long as a product of constant weight is obtained. In the embodiments of this application, the drying temperature is preferably 80°C, and the drying time is preferably 24 hours.

[0078] It should be noted that in the embodiments of this application, the reaction was carried out at room temperature with stirring in the dark for 24 hours.

[0079] It should be noted that in the embodiments of this application, the N atom in the azulene monomer reacts with iodomethane to form a quaternary ammonium cation.

[0080] It should be noted that ethyl acetate in the embodiments of this application is a good solvent for iodomethane, which can dissolve unreacted monomers. At the same time, it is a poor solvent for polymers, causing the polymers to precipitate and thus purifying the polymers.

[0081] In a specific embodiment, the molar ratio of the azulene monomer to the branched monomer in this application embodiment is preferably 0-99:1.

[0082] When the molar ratio of azulene monomer to branched monomer is greater than 99:1, i.e. when the content of branched monomer is too low, the branched monomer has a weak effect on improving the performance of the anion exchange membrane.

[0083] In a specific embodiment, the molar ratio of the sum of the amounts of branched monomers and azulene monomers to the amount of Na2S added is preferably 1:0.9-1.2.

[0084] In a specific embodiment, the molar ratio of the sum of the amounts of branched monomers and azulene monomers to Na2S is preferably 1:0.9-1.5.

[0085] Specifically, when the molar ratio of the sum of the branched monomers and azulene monomers to the diphenol monomer is less than 1:1.2, the local polymerization rate will be too fast, resulting in an excessively wide molecular weight distribution; when the molar ratio of the sum of the branched monomers and azulene monomers to the diphenol monomer is greater than 1:0.9, the reaction yield and rate will decrease.

[0086] In a specific embodiment, the first mixed organic solvent in this application is preferably a mixture of one of dimethyl sulfoxide, N-methylpyrrolidone, N,N-dimethylformamide and toluene.

[0087] In this process, the first mixed organic solvents serve to dissolve the reactants.

[0088] In specific embodiments, the second organic solvent in this application is preferably one of acetonitrile, tetrahydrofuran, N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylacetamide, N,N-dimethylformamide, and sulfolane.

[0089] These second organic solvents serve to dissolve the polymer.

[0090] Thirdly, embodiments of this application provide a polyazine sulfide anion exchange membrane as described in the first aspect, and the application of the polyazine sulfide anion exchange membrane prepared by the method described in the second aspect in the preparation of alkaline fuel cells and alkaline electrolyzers.

[0091] In a specific embodiment, the azulene polysulfone anion exchange membrane of this application is subjected to OH at 80°C. - The conductivity is preferably at least 100 mS / cm.

[0092] The technical methods of this application will be further described below with reference to specific embodiments.

[0093] Example 1

[0094] Preparation of 6-6'-biazine crosslinked poly(6-piperidinazine sulfone) (PSU-Az-BiAz) anion exchange membrane:

[0095] (1) Synthesis of 6-6'-biazine crosslinked poly-6-piperidinazine sulfone (PSU-Az): The monomers p-6-piperidin-1,3-dibromoazine (10 mmol) and 1,3,1',3'-tetrabromo-6,6'-biazine were prepared according to the literature (J.Org.Chem.2015,80,11513-11520 and Journal of Organic Chemistry 2019,84(3),1257-1275; Tetrabromo-6,6'-biazine). 6-Piperidine-1,3-dibromoazine (9.5 mmol), 1,3,1',3'-tetrabromo-6,6'-azine (0.5 mmol), bisphenol S (11 mmol), and potassium carbonate (15 mmol) were added to dimethylacetamide (30 mL) and toluene (25 mL). The solution was refluxed at 140 °C for 8 h, and toluene and water were removed by azeotropic distillation. The reaction was continued at 160 °C for 12 h to obtain a viscous polymer. After cooling the reaction system to room temperature, it was diluted with 25 mL of tetrahydrofuran, and the solution was poured into water to settle. The resulting blue-black polymer fibers were collected and dried under vacuum at 80 °C for 24 h to obtain PSU-Az-BiAz. The dried product was a black solid powder, totaling 7.2 g, with a yield of 96.9%.

[0096] 1 g of the product was dissolved in 30 mL of dimethyl sulfoxide (DMSO), followed by the addition of 0.39 g of K₂CO₃ and 1 mL of iodomethane. The mixture was stirred at room temperature in the dark for 24 h. Ethyl acetate was added to the resulting viscous solution. The pale yellow precipitate was filtered, washed three times with water, and dried under vacuum in an oven at 80 °C for 24 h to obtain PSU-Az-BiAz. The chemical structure of the polymer was determined by NMR and IR characterization. Figure 1 As shown, its weight-average molecular weight was determined to be 60 kDa by GPC testing (the molar ratio of a to b is 95:5, and the polymerization mode of the groups in parentheses corresponding to a and b is random polymerization).

[0097] To facilitate understanding of the above-mentioned synthesis process of 6-6'-biazine-crosslinked poly6-piperidinium azide sulfone (PSU-Az-BiAz), this application provides a synthetic route diagram of 6-6'-biazine-crosslinked poly6-piperidinium azide sulfone (PSU-Az-BiAz), as follows: Figure 1 As shown, Figure 1 Synthetic pathway diagram of 6-6'-biazine crosslinked poly(6-piperidinazine sulfone) (PSU-Az-BiAz) provided in this application.

[0098] (2) Preparation and ion exchange of PSU-Az-BiAz anion exchange membrane: PSU-Az-BiAz (1g) was dissolved in 30mL DMSO. The polymer solution was filtered through a 0.45μm polytetrafluoroethylene filter membrane and cast onto a clean glass plate. Subsequently, the solution was evaporated at 80℃ for 12h, then at 120℃ for 12h, and finally vacuum dried at 120℃ for 24h to completely remove residual solvent. Ion exchange membrane was obtained by peeling it off from the glass plate. - A membrane was prepared. Ion exchange was performed in 1M KCl solution at 80℃ for 12 h, followed by washing three times with deionized water to remove residual salts, yielding Cl... - A membrane of this type was prepared. Ion exchange was performed by incubating the membrane in 1M KOH solution at 80°C for 12 hours, followed by washing three times with deionized water under a nitrogen atmosphere to obtain OH⁻. - Type membrane.

[0099] Example 2

[0100] Preparation of poly(6-piperidine azulene sulfone) (PSU-Az-Pd) anion exchange membrane:

[0101] (1) Synthesis of poly(6-piperidine-azyl sulfone) precursor polymer (PSU-Az-Pd): The monomer p-6-piperidine-1,3-dibromoazine was prepared according to the literature (J.Org.Chem.2015,80,11513-11520). p-6-piperidine-1,3-dibromoazine (10 mmol), bisphenol S (10 mmol), and potassium carbonate (15 mmol) were added to dimethylacetamide (30 mL) and toluene (25 mL). The solution was refluxed at 140 °C for 8 h, and toluene and water were removed by azeotropic distillation. The reaction was continued at 160 °C for 12 h to obtain a viscous polymer. After cooling the reaction system to room temperature, it was diluted with 25 mL of tetrahydrofuran, the solution was poured into water to settle, and the resulting blue polymer fibers were collected; the fibers were dried under vacuum at 80 °C for 24 h to obtain PSU-Az-Pd. The dried product was a black solid powder, totaling 7.5 g, with a yield of 95.6%. 1 g of this product was dissolved in 30 mL of dimethyl sulfoxide (DMSO), followed by the addition of 0.39 g of K₂CO₃ and 1 mL of iodomethane. The mixture was stirred at room temperature in the dark for 24 h. Ethyl acetate was added to the resulting viscous solution. The pale yellow precipitate was filtered, washed three times with water, and dried under vacuum in an oven at 80 °C for 24 h to obtain PSU-Az-Pd. The chemical structure of the polymer was determined by NMR and IR characterization. Figure 1 As shown. GPC testing determined its weight-average molecular weight to be 65 kDa (the molar ratio of a to b is 95:5, and the polymerization mode of the groups in parentheses corresponding to a and b is random polymerization).

[0102] To facilitate understanding of the synthesis process of 6-piperidinazium polysulfone (PSU-Az-Pd), this application provides a synthetic route diagram for 6-piperidinazium polysulfone (PSU-Az-Pd), as follows: Figure 2 As shown, Figure 2 Synthetic pathway diagram of 6-piperidinazolyl polysulfone (PSU-Az-Pd) provided in this application.

[0103] (2) Preparation of polyPSU-Az-Pd anion exchange membrane:

[0104] PSU-Az-Pd (1 g) was dissolved in 30 mL of DMSO. The polymer solution was filtered through a 0.45 μm polytetrafluoroethylene (PTFE) membrane and cast onto a clean glass plate. The solution was then evaporated at 80 °C for 12 h, then at 120 °C for 12 h, and finally vacuum dried at 120 °C for 24 h to completely remove residual solvent. A type I membrane was obtained by peeling it off from the glass plate. Ion exchange was performed in 1 M KCl solution at 80 °C for 12 h, followed by washing three times with deionized water to remove residual salt, yielding Cl... - A membrane of this type was prepared. Ion exchange was performed by incubating the membrane in 1M KOH solution at 80°C for 12 hours, followed by washing three times with deionized water under a nitrogen atmosphere to obtain OH⁻. - The type of membrane is the PSU-Az-Pd anion exchange membrane.

[0105] Example 3

[0106] Preparation of poly(6-pyrrolobenzenesulfone) (PSU-Az-Pr) anion exchange membrane:

[0107] (1) Synthesis of poly(6-piperidinium azenesulfone) precursor polymer (PSU-Az-Pr): The monomer p-6-pyrrole-1,3-dibromoazine was prepared according to the literature (J.Org.Chem.2015,80,11513-11520). p-6-pyrrole-1,3-dibromoazine (10 mmol), bisphenol S (10 mmol), and potassium carbonate (15 mmol) were added to dimethylacetamide (30 mL) and toluene (25 mL). The solution was refluxed at 140 °C for 8 h, and toluene and water were removed by azeotropic distillation. The reaction was continued at 160 °C for 12 h to obtain a viscous polymer. After cooling the reaction system to room temperature, it was diluted with 25 mL of tetrahydrofuran, the solution was poured into water to settle, and the resulting blue polymer fibers were collected; the fibers were dried under vacuum at 80 °C for 24 h to obtain PSU-Az-Pr. The dried product was a black solid powder, totaling 7.5 g, with a yield of 95.6%. 1 g of this product was dissolved in 30 mL of dimethyl sulfoxide (DMSO), followed by the addition of 0.39 g of K₂CO₃ and 1 mL of iodomethane. The mixture was stirred at room temperature in the dark for 24 h. Ethyl acetate was added to the resulting viscous solution. The pale yellow precipitate was filtered, washed three times with water, and dried under vacuum in an oven at 80 °C for 24 h to obtain PSU-Az. The chemical structure of the polymer was determined by NMR and IR characterization. Figure 1 As shown. GPC testing determined its weight-average molecular weight to be 62 kDa (the molar ratio of a to b is 95:5, and the polymerization mode of the groups in parentheses corresponding to a and b is random polymerization).

[0108] To facilitate understanding of the synthesis process of 6-piperidinazolyl polysulfone (PSU-Az-Pr), this application provides a synthetic route diagram for 6-piperidinazolyl polysulfone (PSU-Az-Pr), as follows: Figure 3 As shown, Figure 3 Synthetic pathway diagram for 6-piperidinazolyl polysulfone (PSU-Az-Pr) provided in this application.

[0109] (2) Preparation of poly(PSU-Az-Pr) anion exchange membrane:

[0110] PSU-Az (1 g) was dissolved in 30 mL of DMSO. The polymer solution was filtered through a 0.45 μm polytetrafluoroethylene (PTFE) membrane and cast onto a clean glass plate. The solution was then evaporated at 80 °C for 12 h, then at 120 °C for 12 h, and finally vacuum dried at 120 °C for 24 h to completely remove residual solvent. A type I membrane was obtained by peeling it off from the glass plate. Ion exchange was performed in 1 M KCl solution at 80 °C for 12 h, followed by washing three times with deionized water to remove residual salt, yielding Cl... - A membrane of this type was prepared. Ion exchange was performed by incubating the membrane in 1M KOH solution at 80°C for 12 hours, followed by washing three times with deionized water under a nitrogen atmosphere to obtain OH⁻.- The type of membrane is the PSU-Az-Pr anion exchange membrane.

[0111] To verify the performance of the azurite polysulfone anion exchange membranes prepared in Examples 1-3, performance tests were conducted on the azurite polysulfone anion exchange membrane and the commercial FAA 3-50 anion exchange membrane. The test results are shown in the figure.

[0112] Tests showed that the PSU-Az-BiAz anion exchange membrane prepared in Example 1 had a thickness of 60 micrometers and an OH content of 80°C. - The conductivity is 150 mS / cm, its ion exchange capacity is 2.5 mmol / g, its swelling rate is 20%, its water absorption rate is 46%, its tensile strength is 70 MPa, its elongation at break is 15%, and it maintains alkaline stability in 1M KOH at 80℃ for 1000 h without significant decomposition. Meanwhile, the PSU-Az-Pd anion exchange membrane prepared in Example 2, with a thickness of 60 μm, exhibits alkaline stability at 80℃. - The conductivity is 140 mS / cm, its ion exchange capacity is 2.3 mmol / g, its swelling rate is 22%, its water absorption rate is 46%, its tensile strength is 55 MPa, its elongation at break is 12%, and it maintains alkaline stability in 1M KOH at 80℃ for 1000 h without significant decomposition. The PSU-Az-Pr anion exchange membrane prepared in Example 3 has a thickness of 60 μm and exhibits alkaline stability at 80℃. - The conductivity is 138 mS / cm, the ion exchange capacity is 2.1 mmol / g, the swelling rate is 25%, the water absorption rate is 48%, the tensile strength is 50 MPa, the elongation at break is 10%, and it maintains alkaline stability in 1M KOH at 80℃ for 1000 h without significant decomposition. This indicates that the homogeneous anion exchange membrane prepared in this example has minimal swelling, suitable ion conductivity and anion exchange capacity, and good mechanical properties. Furthermore, with the addition of branched monomers, the OH... - Increased electrical conductivity, decreased swelling ratio, and enhanced mechanical properties. Furthermore, the polyazine sulfide anion exchange membrane prepared in the examples outperformed the commercial FAA 3-50 anion exchange membrane in both electrical conductivity and water electrolysis performance.

[0113] Figure 4 The commercial product FAA3-50OH, an azulene polysulfone anion exchange membrane prepared in Examples 1, 2, and 3. - Conductivity test results.

[0114] Figure 5 The results of water electrolysis tests of the azurite polysulfone anion exchange membranes prepared in Examples 1, 2 and 3 and the commercial product FAA3-50 anion exchange membrane.

[0115] Figure 6 The water absorption test results of the commercial product FAA3-50, azulene polysulfone anion exchange membrane prepared in Examples 1, 2 and 3.

[0116] Figure 7 The swelling rate test results of the azulene polysulfone anion exchange membrane FAA3-50 commercial product prepared in Examples 1, 2 and 3.

[0117] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An azulene-based polysulfone anion exchange membrane, characterized in that, The raw material for the azulene-based polysulfone anion exchange membrane is an azulene-based polysulfone polymer, the structure of which is at least one or more of the following: Formula I or Formula II: ； Formula I is a linear azulene polysulfone, where R2 is a monomer with two arms or two connecting sites; ； Formula II is a cross-linked azulene polysulfone, where R2 is a monomer with four arms or four connecting sites; Wherein, R1 represents different types of cationic groups, R2 is a copolymer or branched monomer, a and b represent the percentage of molar content of the two repeating units, the value of a is between 0 and 100, the value of b is between 0 and 100, and a + b = 100; R1 is at least one or more of the following structures: In group R1, n is an integer greater than or equal to 0; R2 is at least one or more of the following structures: In the above structure, the wavy line "﹏" represents the connection point. Two wavy lines "﹏" indicate that the unit uses two arms or two connection points, and four wavy lines "﹏" indicate that the unit uses four arms or four connection points.

2. The azulene polysulfone anion exchange membrane according to claim 1, characterized in that, The weight-average molecular weight of the azulene polysulfone polymer of formula I ranges from 1.0 to 10.0 kDa; the film thickness is 10-200 μm; to ensure film formation, the crosslinking monomer corresponding to the R2 group is a two-armed or two-linked monomer, or a combination of a two-armed or two-linked monomer and a four-armed or four-linked monomer. When a combination of a two-armed or two-linked monomer and a four-armed or four-linked monomer is used, the molar percentage of the four-armed or four-linked monomer is 0.01%-10%.

3. A method for preparing the azulene polysulfone anion exchange membrane according to claim 1 or 2, characterized in that, Includes the following steps: (1) Synthesis of azulene polysulfone precursor polymer: Under alkaline catalytic conditions, diphenyl sulfone monomer and azulene monomer are dissolved in organic solvents α and β in the required ratio, and a condensation reaction is carried out to generate azulene polysulfone polymer PSU-Az; The PSU-Az polymer is synthesized using one of three methods: N,N-dimethylacetamide / potassium carbonate (DMAc / K2CO3), dimethyl sulfoxide / sodium hydroxide (DMSO / NaOH), or dimethyl sulfoxide / potassium hydroxide (DMSO / KOH). The DMAc / K2CO3 method employs a one-step process to prepare the polymer: First, under N2 protection, diphenol monomer, azulene monomer, K2CO3, DMAc, and toluene are added to a dry container in a specific ratio. Then, the mixture in the container is heated under reflux at 120-140 °C for 4-12 h, and toluene and water are removed by azeotropic distillation. The mixture is then heated further at 160-180 °C for 8-18 h to obtain a viscous polymer solution. After cooling to room temperature, the viscous polymer solution is diluted with THF, and the diluted solution is poured into water to obtain a blue-black fibrous polymer. This polymer is then vacuum dried at 80-120 °C for 16-48 h to obtain the target product. The DMSO / KOH and DMSO / NaOH methods employ two-step processes to prepare the polymer, as follows: Under N2 protection, diphenol monomer, KOH or NaOH, DMAc, and toluene are added to a dry container in a certain proportion and refluxed at 120-140 °C for 4-10 hours. Water and toluene are removed by azeotropic distillation, and the temperature is slowly raised to 160-180 °C. Subsequently, azulene monomer is added to the system, and the reaction is carried out at 160-180 °C for 0.5-2 hours to obtain a viscous polymer solution. After cooling to room temperature, the viscous polymer solution is diluted with THF, and the diluted solution is poured into water to obtain a blue-black fibrous polymer. This polymer is then vacuum dried at 80-120 °C for 16-48 hours to obtain the target product. (2) Synthesis of cationic azulene polysulfone: The azulene polysulfone obtained in step 1 was dissolved in organic solvent δ, heated to dissolve, and an excess of γ reagent with cationic groups was added. The reaction was carried out in the dark by heating and stirring. The resulting solution was placed in water to precipitate, and the resulting solid was washed with water and dried. (3) Preparation of azulene polysulfone anion exchange membrane: The cationized azulene polysulfone obtained in step (2) was dissolved in organic solvent δ, stirred at room temperature and filtered. The filtrate was cast onto a plate, heated to 40-80℃ to remove the solvent, and then the membrane was peeled off from the plate to obtain Cl. - ,Br - Or I - Type membrane, then Cl - ,Br - Or I - The membrane was placed in KOH solution for ion exchange to obtain OH-. - The membrane was then washed with water under an inert atmosphere to obtain an azulene polysulfone anion exchange membrane.

4. The preparation method according to claim 3, characterized in that, In step (1), the molar ratio of azulene monomer to diphenyl sulfone monomer is 1:0.9-1.

2.

5. The preparation method according to claim 3, characterized in that, In step (1), the volume ratio of solvent α to β is 1:0.8-1.2; The organic solvent α is selected from at least one or more of DMSO, DMAc, N,N-dimethylformamide (DMF), or N-methylpyrrolidone (NMP); The organic solvent β is selected from at least one or more of benzene, toluene, o-xylene, m-xylene, p-xylene, p-trimethylene, and m-trimethylene.

6. The preparation method according to claim 3, characterized in that, In step (2) or (3), the organic solvent δ is selected from at least one or more of acetonitrile, tetrahydrofuran, N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylacetamide, N,N-dimethylformamide or sulfolane; In step (2), the solid content of azulene polysulfone dissolved in organic solvent β is 0.01-50 wt%. The heating and dissolution temperature is 20-120℃; the ratio of γ reagent to azulene polysulfone is 0.1-100:1; the reaction is carried out in the dark at room temperature with stirring for 1-100 h; the γ reagent is one or more of the following structures: CH3X, ; Where X is Cl, Br or I, and n is an integer greater than or equal to 0.

7. The application of the azurite polysulfone anion exchange membrane according to claim 1 or 2, or the azurite polysulfone anion exchange membrane prepared by any one of claims 3-6, as a separator in a fuel cell or an alkaline electrolyzer.

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