Preparation method and application of anion exchange membrane

Abstract

The invention belongs to the technical field of anion exchange membranes, and provides a preparation method and application of an anion exchange membrane, and the preparation method comprises the following steps: A, mixing p-terphenyl, N-methyl-4-piperidone and 2, 2, 2-trifluoroacetophenone, stirring, dropwise adding a catalyst, stirring to react for 30-50 minutes, heating to room temperature, continuing to react for 20-22 hours, precipitating, filtering, washing, soaking in a neutralizing agent, filtering, and drying to obtain an anion exchange membrane; washing to be neutral, and drying to obtain a polymer a; the catalyst is trifluoroacetic acid, 4-ethyl benzenesulfonic acid and trifluoromethanesulfonic acid in a ratio of (3-4mL): (5-6g): (65-67mL); the molar ratio of the trifluoromethanesulfonic acid to the p-terphenyl is (7.2-8.6): 1; b, performing quaternization reaction on the polymer a to prepare a polymer b; c, preparing the polymer b into a film coating solution, and coating the film coating solution to obtain a prefabricated film; and carrying out ion exchange treatment on the prefabricated membrane to obtain the anion exchange membrane. The anion exchange membrane prepared by the invention has good ionic conductivity and chemical stability.

Description

Technical Field

[0001] The invention belongs to the technical field of anion exchange membranes and relates to a preparation method and application of anion exchange membranes. Background Art

[0002] Anion Exchange Membrane (AEM): An ion exchange membrane containing positively charged groups (such as quaternary ammonium groups, imidazolium groups, etc.), which can selectively pass anions while blocking cations and other substances. Anion exchange membranes are widely used in the field of electrochemistry, such as alkaline fuel cells, water electrolysis for hydrogen production, electrodialysis, etc. In alkaline fuel cells, anion exchange membranes can conduct hydroxide ions (OH − ), realize the charge transfer inside the battery; in water electrolysis to produce hydrogen, it can improve the electrolysis efficiency and reduce energy consumption.

[0003] Anion exchange membrane water electrolysis technology combines the low cost of alkaline water electrolysis with the high efficiency of proton exchange membrane water electrolysis, and is a key path for large-scale hydrogen production in the future. The current anion exchange membrane is mainly composed of different polymer skeletons grafted with cationic groups, among which the cationic groups are mainly quaternary ammonium groups. There is a certain degree of contradiction between the ion exchange capacity and mechanical strength of this type of anion exchange membrane. For example, when the ion exchange capacity is too large and the water content is too high, the membrane is prone to brittle cracking. However, when the ion exchange capacity is too small, although the mechanical strength of the membrane is guaranteed, the ion conductivity is greatly reduced. In addition, the quaternized polymer anion exchange membrane may be affected by OH under strong alkaline and high temperature conditions. - Nucleophilic attack by the quaternary ammonium groups causes them to detach from the skeleton, leading to chemical degradation of the membrane and a decrease in conductivity and mechanical strength. For example, Chinese patent publication number CN 113801352 A provides a cross-linked anion exchange membrane that simultaneously achieves in-situ crosslinking by quaternizing the membrane material. This introduces both ion exchange sites and a cross-linked network. This not only improves the membrane's ion conductivity but also limits membrane swelling and improves its mechanical strength. However, this approach does not address the alkali resistance or stability of the anion exchange membrane.

[0004] Therefore, how to improve the conductivity and stability of anion exchange membranes has become a technical problem that urgently needs to be solved. Summary of the Invention

[0005] The present invention provides a preparation method and application of an anion exchange membrane. The anion exchange membrane prepared by the present invention has good ion conductivity and chemical stability.

[0006] The technical solution of the present invention is achieved as follows: A method for preparing an anion exchange membrane comprises the following steps: A. p-terphenyl, N-methyl-4-piperidone, and 2,2,2-trifluoroacetophenone in a molar ratio of 89-90:80-85:9-15 are mixed in a first solvent, stirred, and a catalyst is added dropwise at -6°C-0°C. After the addition is complete, the mixture is stirred and reacted for 30-50 minutes, the mixture is warmed to room temperature, and the mixture is stirred and reacted for 20-22 hours. The mixture is precipitated, filtered, washed, soaked in a neutralizer, filtered, washed with water until neutral, and dried to obtain polymer a; the catalyst is 3-4 mL: 5-6 g: 65-67 mL of trifluoroacetic acid, 4-ethylbenzenesulfonic acid, and trifluoromethanesulfonic acid; and the molar ratio of trifluoromethanesulfonic acid to p-terphenyl is 7.2-8.6:1; B. dissolving polymer a in a second solvent, adding a halogenated alkane to carry out a quaternization reaction on polymer a to prepare polymer b; C. dissolving the polymer b in a third solvent to form a coating solution, and applying the coating solution to obtain a prefabricated film; The prefabricated membrane is subjected to ion exchange treatment to obtain an anion exchange membrane.

[0007] Preferably, the heating to room temperature in step A adopts the following conditions: the heating rate of the first step to 10°C is 0.5-1.0°C / min, and the heating rate of 10°C to room temperature is 1.0-1.5°C / min.

[0008] Preferably, the molar ratio of p-terphenyl, N-methyl-4-piperidone and 2,2,2-trifluoroacetophenone is 89.66:80.02-84.7:9.41-14.12.

[0009] Preferably, the first solvent is dichloromethane and 2-methyltetrahydrofuran in a volume ratio of 1.5-2.5:1.

[0010] Preferably, the molar ratio of trifluoromethanesulfonic acid to p-terphenyl is 8.2-8.6:1.

[0011] Preferably, the catalyst is trifluoroacetic acid, 4-ethylbenzenesulfonic acid and trifluoromethanesulfonic acid in a ratio of 3 mL:6 g:67 mL.

[0012] Preferably, the neutralizing agent is sodium carbonate, potassium carbonate or sodium bicarbonate.

[0013] Preferably, the neutralizing agent is potassium carbonate.

[0014] Preferably, the specific conditions for soaking in the neutralizer include: soaking in 1-1.5 mol / L K2CO3 at 45-55°C for 10-16 hours.

[0015] Preferably, the specific conditions for drying include: vacuum drying at 60-70° C. for 20-26 hours.

[0016] Preferably, the usage ratio of the halogenated alkane and polymer a is 0.8-1.8 mL:1.0 g.

[0017] Preferably, the usage ratio of the halogenated alkane and polymer a is 1.0-1.5 mL:1.0 g.

[0018] Preferably, the ion exchange treatment uses a 1-2 mol / L sodium hydroxide solution or potassium hydroxide solution.

[0019] Preferably, the ion exchange treatment uses a 1 mol / L potassium hydroxide solution.

[0020] Preferably, the quaternization reaction is stirred at room temperature in the dark for more than 12 hours.

[0021] Preferably, after the quaternization reaction, the reaction product is poured into ethyl acetate for precipitation, filtered, washed, and dried to obtain polymer B. Further preferably, the washing is performed alternately with ethyl acetate and deionized water. Further preferably, the specific drying conditions include vacuum drying at 60-70° C. for 20-26 hours.

[0022] Preferably, the halogenated alkane is methyl iodide, ethyl iodide or propyl iodide.

[0023] Preferably, the halogenated alkane is methyl iodide.

[0024] Preferably, the usage ratio of the polymer b and the third solvent is 0.4-0.6 g: 9-12 mL.

[0025] Preferably, the usage ratio of the polymer b and the third solvent is 0.5 g:10 mL.

[0026] Preferably, the first solvent is dichloromethane and 2-methyltetrahydrofuran in a volume ratio of 2:1.

[0027] Preferably, the usage ratio of the p-terphenyl and the first solvent is 89-90 mmol:75-80 mL.

[0028] Preferably, the second solvent is dimethyl sulfoxide, N-methylpyrrolidone, N,N-dimethylformamide or N,N-dimethylacetamide.

[0029] Preferably, the second solvent is dimethyl sulfoxide.

[0030] Preferably, the usage ratio of the polymer a and the second solvent is 1.0 g: 18-25 mL.

[0031] Preferably, the third solvent is dimethyl sulfoxide, N-methylpyrrolidone, N,N-dimethylformamide or N,N-dimethylacetamide.

[0032] Preferably, the third solvent is dimethyl sulfoxide.

[0033] The present invention also provides an anion exchange membrane prepared by the anion exchange membrane preparation method.

[0034] The present invention also provides the use of the anion exchange membrane in producing hydrogen by electrolysis of water.

[0035] The beneficial effects of the present invention are: This invention utilizes a synergistic acid catalytic system, optimized solvent system, and step-by-step temperature ramping to improve the ionic conductivity and chemical stability of anion exchange membranes. The synergistic solvent system in step A avoids side reactions caused by localized monomer concentration imbalances, while promoting uniform catalyst dispersion and reducing the risk of degradation caused by localized over-acidity. The synergistic acid catalytic system enhances reaction activity. Temperature control is implemented in stages (-6°C to 0°C → 10°C → 25°C), and rate control (0.5-1.0°C / min → 1.0-1.5°C / min) is used to reduce byproducts. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] Figure 1 This is the hydrogen nuclear magnetic resonance spectrum of the anion exchange membrane prepared in Example 1 of the present invention.

[0038] Figure 2 This is a sampling diagram in step A of Example 1 of the present invention. DETAILED DESCRIPTION

[0039] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0040] Unless otherwise defined, all technical terms and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the technical field of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The experimental techniques or test methods involved in the embodiments of the present invention, unless otherwise specified, are conventional methods in the prior art, and their names and / or abbreviations are conventional names in this area, and are very clear and definite in the relevant application fields. Those skilled in the art can understand conventional process steps and apply corresponding equipment according to the names, and implement them according to conventional conditions or conditions recommended by the manufacturer. The various instruments, equipment, raw materials or reagents used in the embodiments of the present invention have no special restrictions on source, are conventional products that can be purchased through regular commercial channels, and can also be prepared according to conventional methods well known to those skilled in the art.

[0041] The raw materials in the following examples and comparative examples were pretreated to remove water: p-terphenyl was vacuum dried at 80°C for 24 h; Dichloromethane was used to remove water.

[0042] Example 1 A method for preparing an anion exchange membrane comprises the following steps: A. Dissolve p-terphenyl (20.6487 g, 89.66 mmol) in 50 mL of dichloromethane and 25 mL of 2-methyltetrahydrofuran. Use a mechanical stirrer to stir thoroughly (mechanical stirring rate 200 rpm) for 1 hour. Add N-methyl-4-piperidone (84.7 mmol) and 2,2,2-trifluoroacetophenone (9.41 mmol) dropwise simultaneously using a peristaltic pump (1.5 rpm). Stir mechanically for 10 minutes and mix thoroughly. At 0°C, use a peristaltic pump to (1.0 rpm: addition time is 80 min) Slowly add a mixed solution of trifluoroacetic acid (3 mL), 4-ethylbenzenesulfonic acid (6 g) and trifluoromethanesulfonic acid (67 mL). After the addition is complete, continue the reaction at 0°C for 40 min, then increase the temperature to 10°C at a heating rate of 0.8°C / min, and then increase the temperature to 25°C (room temperature) at a heating rate of 1.2°C / min. Continue stirring and keep the reaction warm (mechanical stirring rate is 200 rpm). Samples are taken during the process for observation. The samples taken are as follows Figure 2 , react for 21 hours, pour into anhydrous methanol for precipitation, filter the white fiber solid, wash with methanol three times, soak in 1 mol / L K2CO3 at 50 ° C for 12 hours, filter, wash with water until neutral, and vacuum dry at 60 ° C for 24 hours to obtain polymer a; B. Dissolve 1.0 g of polymer a in 20 mL of dimethyl sulfoxide (DMSO) in a 50 mL single-necked flask equipped with a rotor, add 1.5 mL of iodomethane, and stir in the dark at room temperature for 16 hours. Pour the resulting viscous yellow solution into ethyl acetate for precipitation, filter, and wash alternately with ethyl acetate and deionized water. Dry under vacuum at 60°C for 24 hours to obtain polymer b. C. Dissolve 0.5 g of polymer b in 10 mL of dimethyl sulfoxide to obtain a coating solution. After filtering out impurities, apply the coating solution on a glass plate (spread flat on a clean and smooth glass plate), and dry at 60° C. for 24 h to obtain a prefabricated membrane; perform ion exchange treatment on the prefabricated membrane using a 1 mol / L KOH solution for 72 h to prepare the anion exchange membrane.

[0043] like Figure 1 This is the hydrogen nuclear magnetic resonance spectrum of the anion exchange membrane prepared in this example.

[0044] Example 2 A method for preparing an anion exchange membrane comprises the following steps: A. Dissolve p-terphenyl (20.6487 g, 89.66 mmol) in 48 mL of dichloromethane and 32 mL of 2-methyltetrahydrofuran. Use a mechanical stirrer to stir thoroughly (mechanical stirring rate 200 rpm) for 1 h. Add N-methyl-4-piperidone (9.054 g, 80.02 mmol) and 2,2,2-trifluoroacetophenone (2.458 g, 14.12 mmol) dropwise simultaneously via a peristaltic pump (1.0 rpm). Stir mechanically for 10 min and mix well. At 0 °C, slowly add trifluoroacetic acid (4 mL), a mixed solution of 4-ethylbenzenesulfonic acid (5 g) and trifluoromethanesulfonic acid (65 mL), after completion of the dropwise addition, the reaction was continued at 0°C for 40 min, then the temperature was raised to 10°C at a heating rate of 0.5°C / min, and then the temperature was raised to 25°C (room temperature) at a heating rate of 1.0°C / min, and the reaction was continued with stirring (mechanical stirring rate of 200 rpm), and the reaction was continued for 20 h. The mixture was poured into anhydrous methanol for precipitation, and the white fibrous solid was filtered, washed with methanol 5 times, soaked in 1 mol / L K2CO3 at 50°C for 12 h, filtered, washed with water until neutral, and dried in vacuo at 60°C for 24 h to obtain polymer a; B. Dissolve 1.0 g of polymer a in N,N-dimethylformamide (25 mL) in a 50 mL single-necked flask equipped with a rotor, add 1.0 mL of iodomethane, and stir at room temperature in the dark for 14 hours. Pour the resulting viscous yellow solution into ethyl acetate for precipitation, filter, and wash alternately with ethyl acetate and deionized water. Dry under vacuum at 65°C for 20 hours to obtain polymer b. C. Dissolve 0.5 g of polymer b in 12 mL of N,N-dimethylacetamide to obtain a coating solution. After filtering out impurities, apply the coating solution on a glass plate (spread flat on a clean and smooth glass plate), and dry at 65° C. for 26 hours to obtain a prefabricated membrane; perform ion exchange treatment on the prefabricated membrane using a 1 mol / L KOH solution for 72 hours to prepare the anion exchange membrane.

[0045] Example 3 A method for preparing an anion exchange membrane comprises the following steps: A. Dissolve p-terphenyl (20.6487 g, 89.66 mmol) in 55 mL of dichloromethane and 25 mL of 2-methyltetrahydrofuran. Use a mechanical stirrer to fully stir (mechanical stirring rate 200 rpm) for 1 hour. Add N-methyl-4-piperidone (84.7 mmol) and 2,2,2-trifluoroacetophenone (9.41 mmol) dropwise simultaneously through a peristaltic pump (1.5 rpm). Stir mechanically for 10 minutes and mix well. At 0°C, slowly add trifluoroacetic acid (3 mL) and 4-ethyl benzoate (1 mL) dropwise through a peristaltic pump (1.0 rpm: addition time 80 minutes). After the addition of a mixed solution of benzenesulfonic acid (6 g) and trifluoromethanesulfonic acid (65 mL), the reaction was continued at 0°C for 40 min, then the temperature was increased to 10°C at a heating rate of 1.0°C / min, and then the temperature was increased to 25°C (room temperature) at a heating rate of 1.5°C / min. The reaction was continued with stirring (mechanical stirring rate of 200 rpm) for 21 h, and then poured into anhydrous methanol for precipitation. The white fibrous solid was filtered, washed with methanol four times, immersed in 1 mol / L K2CO3 at 55°C for 10 h, filtered, washed with water until neutral, and vacuum dried at 60°C for 24 h to obtain polymer a. B. Dissolve 1.0 g of polymer a in 20 mL of dimethyl sulfoxide (DMSO) in a 50 mL single-necked flask equipped with a rotor, add 1.0 mL of iodomethane, and stir in the dark at room temperature for 18 h. Pour the resulting viscous yellow solution into ethyl acetate for precipitation, filter, and wash alternately with ethyl acetate and deionized water. Dry under vacuum at 60°C for 24 h to obtain polymer b. C. Dissolve 0.4 g of polymer b in 9 mL of dimethyl sulfoxide to obtain a coating solution. After filtering out impurities, apply the coating solution on a glass plate (spread flat on a clean and smooth glass plate), and dry at 60° C. for 24 hours to obtain a prefabricated membrane; use 1 mol / L sodium hydroxide solution to perform ion exchange treatment on the prefabricated membrane for 72 hours to prepare the anion exchange membrane.

[0046] Comparative Example 1 Compared with Example 1, the only difference is that the catalyst used is a mixed solution of trifluoroacetic acid (3 mL) and trifluoromethanesulfonic acid (69.5 mL, 4-ethylbenzenesulfonic acid is replaced with an equal molar amount of trifluoromethanesulfonic acid). The details are as follows: A. Dissolve p-terphenyl (20.6487 g, 89.66 mmol) in 50 mL of dichloromethane and 25 mL of 2-methyltetrahydrofuran. Use a mechanical stirrer to stir thoroughly (mechanical stirring rate 200 rpm) for 1 hour. Add N-methyl-4-piperidone (84.7 mmol) and 2,2,2-trifluoroacetophenone (9.41 mmol) dropwise simultaneously using a peristaltic pump (1.5 rpm). Stir mechanically for 10 minutes to mix thoroughly. At 0°C, slowly add trifluoroacetic acid (3 mL) dropwise using a peristaltic pump (1.0 rpm: addition time 80 minutes). and trifluoromethanesulfonic acid (69.5 mL) were added dropwise, and the reaction was continued at 0°C for 40 min, then the temperature was raised to 10°C at a heating rate of 0.8°C / min, and then the temperature was raised to 25°C (room temperature) at a heating rate of 1.2°C / min, and the reaction was continued with stirring (mechanical stirring rate of 200 rpm), and the reaction was continued for 21 h. The reaction was poured into anhydrous methanol for precipitation, and the white fibrous solid was filtered, washed with methanol 3 times, soaked in 1 mol / L K2CO3 at 50°C for 12 h, filtered, washed with water until neutral, and vacuum dried at 60°C for 24 h to obtain polymer a; B. Dissolve 1.0 g of polymer a in 20 mL of dimethyl sulfoxide (DMSO) in a 50 mL single-necked flask equipped with a rotor. Add 1.5 mL of iodomethane and stir in the dark at room temperature for 16 hours. Pour the resulting viscous yellow solution into ethyl acetate for precipitation, filter, and wash alternately with ethyl acetate and deionized water. Dry under vacuum at 60°C for 24 hours to obtain polymer b. C. Dissolve 0.5 g of polymer b in 10 mL of dimethyl sulfoxide to obtain a coating solution. After filtering out impurities, apply the coating solution on a glass plate (spread flat on a clean and smooth glass plate), and dry at 60° C. for 24 h to obtain a prefabricated membrane; perform ion exchange treatment on the prefabricated membrane using a 1 mol / L KOH solution for 72 h to prepare the anion exchange membrane.

[0047] Comparative Example 2 Compared with Example 1, the only difference is that p-terphenyl (20.6487 g, 89.66 mmol) is dissolved in 75 mL of dichloromethane. The details are as follows: A. Dissolve p-terphenyl (20.6487 g, 89.66 mmol) in 75 mL of dichloromethane and stir thoroughly with a mechanical stirrer (mechanical stirring rate 200 rpm) for 1 h. Add N-methyl-4-piperidone (84.7 mmol) and 2,2,2-trifluoroacetophenone (9.41 mmol) dropwise simultaneously using a peristaltic pump (1.5 rpm). Stir mechanically for 10 min and mix well. At 0 °C, slowly add trifluoroacetic acid (3 mL) and 4-ethylbenzenesulfonic acid (6 g) dropwise using a peristaltic pump (1.0 rpm: addition time 80 min). ) and trifluoromethanesulfonic acid (67 mL). After the addition was complete, the reaction was continued at 0°C for 40 min, then the temperature was raised to 10°C at a heating rate of 0.8°C / min, and then raised to 25°C (room temperature) at a heating rate of 1.2°C / min. The mixture was stirred and kept warm (mechanical stirring rate of 200 rpm) for 21 h, and then poured into anhydrous methanol for precipitation. The white fibrous solid was filtered, washed with methanol three times, immersed in 1 mol / L K2CO3 at 50°C for 12 h, filtered, washed with water until neutral, and dried in vacuo at 60°C for 24 h to obtain polymer a. B. Dissolve 1.0 g of polymer a in 20 mL of dimethyl sulfoxide (DMSO) in a 50 mL single-necked flask equipped with a rotor, add 1.5 mL of iodomethane, and stir in the dark at room temperature for 16 hours. Pour the resulting viscous yellow solution into ethyl acetate for precipitation, filter, and wash alternately with ethyl acetate and deionized water. Dry under vacuum at 60°C for 24 hours to obtain polymer b. C. Dissolve 0.5 g of polymer b in 10 mL of dimethyl sulfoxide to obtain a coating solution. After filtering out impurities, apply the coating solution on a glass plate (spread flat on a clean and smooth glass plate), and dry at 60° C. for 24 h to obtain a prefabricated membrane; perform ion exchange treatment on the prefabricated membrane using a 1 mol / L KOH solution for 72 h to prepare the anion exchange membrane.

[0048] Comparative Example 3 Compared with Example 1, the only difference is that p-terphenyl (20.6487 g, 89.66 mmol) is dissolved in 75 mL of 2-methyltetrahydrofuran. The details are as follows: A. Dissolve p-terphenyl (20.6487 g, 89.66 mmol) in 75 mL of 2-methyltetrahydrofuran and stir thoroughly with a mechanical stirrer (mechanical stirring rate 200 rpm) for 1 h. Add N-methyl-4-piperidone (84.7 mmol) and 2,2,2-trifluoroacetophenone (9.41 mmol) dropwise simultaneously using a peristaltic pump (1.5 rpm). Stir mechanically for 10 min and mix well. At 0 °C, slowly add trifluoroacetic acid (3 mL) and 4-ethylbenzenesulfonic acid ( After the addition was complete, the mixture was stirred at 0°C for 40 min, then heated to 10°C at a heating rate of 0.8°C / min, and then heated to 25°C (room temperature) at a heating rate of 1.2°C / min. The mixture was stirred and kept warm (mechanical stirring rate of 200 rpm) for 21 h, and then poured into anhydrous methanol for precipitation. The white fibrous solid was filtered, washed with methanol three times, soaked in 1 mol / L K2CO3 at 50°C for 12 h, filtered, washed with water until neutral, and dried in vacuo at 60°C for 24 h to obtain polymer a. B. Dissolve 1.0 g of polymer a in 20 mL of dimethyl sulfoxide (DMSO) in a 50 mL single-necked flask equipped with a rotor, add 1.5 mL of iodomethane, and stir in the dark at room temperature for 16 hours. Pour the resulting viscous yellow solution into ethyl acetate for precipitation, filter, and wash alternately with ethyl acetate and deionized water. Dry under vacuum at 60°C for 24 hours to obtain polymer b. C. Dissolve 0.5 g of polymer b in 10 mL of dimethyl sulfoxide to obtain a coating solution. After filtering out impurities, apply the coating solution on a glass plate (spread flat on a clean and smooth glass plate), and dry at 60° C. for 24 h to obtain a prefabricated membrane; perform ion exchange treatment on the prefabricated membrane using a 1 mol / L KOH solution for 72 h to prepare the anion exchange membrane.

[0049] Comparative Example 4 Compared with Example 1, the only difference is that after the catalyst is added dropwise in step A, the temperature is directly raised from 0°C to 25°C at a heating rate of 1.2°C / min and the reaction is carried out for 21 hours. The details are as follows: A. Dissolve p-terphenyl (20.6487 g, 89.66 mmol) in 50 mL of dichloromethane and 25 mL of 2-methyltetrahydrofuran. Use a mechanical stirrer to stir thoroughly (mechanical stirring rate 200 rpm) for 1 hour. Add N-methyl-4-piperidone (84.7 mmol) and 2,2,2-trifluoroacetophenone (9.41 mmol) dropwise simultaneously using a peristaltic pump (1.5 rpm). Stir mechanically for 10 minutes to mix thoroughly. At 0°C, use a peristaltic pump (1.0 rpm: addition time 80 minutes) to add the mixture. A mixed solution of trifluoroacetic acid (6 mL), 4-ethylbenzenesulfonic acid (3 mL) and trifluoromethanesulfonic acid (70 mL) was slowly added dropwise. After the addition was complete, the temperature was directly increased from 0°C to 25°C at a heating rate of 1.2°C / min, and the reaction was continued with stirring (mechanical stirring rate of 200 rpm). The reaction was continued for 21 hours, and the mixture was poured into anhydrous methanol for precipitation. The white fibrous solid was filtered, washed with methanol three times, immersed in 1 mol / L K2CO3 at 50°C for 12 hours, filtered, washed with water until neutral, and vacuum dried at 60°C for 24 hours to obtain polymer a. B. Dissolve 1.0 g of polymer a in 20 mL of dimethyl sulfoxide (DMSO) in a 50 mL single-necked flask equipped with a rotor, add 1.5 mL of iodomethane, and stir in the dark at room temperature for 16 hours. Pour the resulting viscous yellow solution into ethyl acetate for precipitation, filter, and wash alternately with ethyl acetate and deionized water. Dry under vacuum at 60°C for 24 hours to obtain polymer b. C. Dissolve 0.5 g of polymer b in 10 mL of dimethyl sulfoxide to obtain a coating solution. After filtering out impurities, apply the coating solution on a glass plate (spread flat on a clean and smooth glass plate), and dry at 60° C. for 24 h to obtain a prefabricated membrane; perform ion exchange treatment on the prefabricated membrane using a 1 mol / L KOH solution for 72 h to prepare the anion exchange membrane.

[0050] The performance comparison table of the anion exchange membranes prepared in the examples and comparative examples is shown in Table 1 below.

[0051] Table 1 Test Method 1. Ionic conductivity test Standard basis: Refer to GB / T 20042.3-2009 "Proton exchange membrane fuel cells Part 3: Proton exchange membrane test method" and adjust to adapt to anion exchange membrane testing.

[0052] Test conditions: Temperature: 80℃.

[0053] Humidity: 100% RH.

[0054] Electrolyte: 1 M KOH solution.

[0055] Test steps: The membrane was cut into 2 cm × 2 cm squares and immersed in 1 M KOH for 24 h until completely swollen; Measure the surface resistance (R, Ω·cm²) of the membrane using a four-electrode electrochemical workstation (such as Princeton PARSTAT 4000); Calculate the conductivity (σ, mS / cm): Where L is the film thickness (cm) and A is the electrode contact area (cm²).

[0056] 2. Mechanical properties test Standard basis: GB / T 1040.3-2006 "Determination of tensile properties of plastics Part 3: Test conditions for film and sheeting".

[0057] Test conditions: Temperature: 25℃.

[0058] Humidity: 50%RH.

[0059] Tensile rate: 10 mm / min.

[0060] Test steps: The membrane was cut into dumbbell-shaped specimens (gauge length 20 mm, width 4 mm); The tensile strength and elongation at break were tested using a universal material testing machine.

[0061] 3. Chemical stability test Test conditions: Solution: 2M KOH, 80°C.

[0062] Immersion time: 1000 hours.

[0063] Test steps: The membrane was immersed in 2 M KOH solution, and fresh solution was replaced every 24 hours.

[0064] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing an anion exchange membrane, characterized in that: The steps include: A. p-terphenyl, N-methyl-4-piperidone, and 2,2,2-trifluoroacetophenone in a molar ratio of 89-90:80-85:9-15 are mixed in a first solvent, stirred, and a catalyst is added dropwise at -6°C-0°C. After the addition is complete, the mixture is stirred and reacted for 30-50 minutes, the mixture is warmed to room temperature, and the mixture is stirred and reacted for 20-22 hours. The mixture is precipitated, filtered, washed, soaked in a neutralizer, filtered, washed with water until neutral, and dried to obtain polymer a; the catalyst is 3-4 mL: 5-6 g: 65-67 mL of trifluoroacetic acid, 4-ethylbenzenesulfonic acid, and trifluoromethanesulfonic acid; and the molar ratio of trifluoromethanesulfonic acid to p-terphenyl is 7.2-8.6:1; B. dissolving polymer a in a second solvent, adding a halogenated alkane to carry out a quaternization reaction on polymer a to prepare polymer b; C. dissolving the polymer b in a third solvent to form a coating solution, and applying the coating solution to obtain a prefabricated film; The prefabricated membrane is subjected to ion exchange treatment to obtain an anion exchange membrane.

2. The method for preparing an anion exchange membrane according to claim 1, wherein: The heating to room temperature in step A is carried out under the following conditions: the heating rate to 10°C in the first step is 0.5-1.0°C / min, and the heating rate from 10°C to room temperature is 1.0-1.5°C / min.

3. The method for preparing an anion exchange membrane according to claim 1, wherein: The molar ratio of the p-terphenyl, N-methyl-4-piperidone and 2,2,2-trifluoroacetophenone is 89.66:80.02-84.7:9.41-14.

12.

4. The method for preparing an anion exchange membrane according to claim 1, wherein: The first solvent is dichloromethane and 2-methyltetrahydrofuran in a volume ratio of 1.5-2.5:

1.

5. The method for preparing an anion exchange membrane according to claim 1, wherein: The neutralizing agent is sodium carbonate, potassium carbonate or sodium bicarbonate.

6. The method for preparing an anion exchange membrane according to claim 1, wherein: The halogenated alkane is methyl iodide, ethyl iodide or propyl iodide; The usage ratio of the halogenated alkane and polymer a is 0.8-1.8 mL:1.0 g.

7. The method for preparing an anion exchange membrane according to claim 1, wherein: The ion exchange treatment uses 1-2 mol / L sodium hydroxide solution or potassium hydroxide solution.

8. The method for preparing an anion exchange membrane according to claim 1, wherein: The second solvent is dimethyl sulfoxide, N-methylpyrrolidone, N,N-dimethylformamide or N,N-dimethylacetamide; The third solvent is dimethyl sulfoxide, N-methylpyrrolidone, N,N-dimethylformamide or N,N-dimethylacetamide; The relationship between the amount of p-terphenyl and the first solvent is 89-90 mmol: 75-80 mL; The relationship between the amount of polymer a and the second solvent is 1.0 g: 18-25 mL; The usage ratio of polymer b and the third solvent is 0.4-0.6 g: 9-12 mL.

9. An anion exchange membrane prepared by the method for preparing an anion exchange membrane according to any one of claims 1 to 8.

10. Use of the anion exchange membrane according to claim 9 in hydrogen production by water electrolysis.

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