A basic anion exchange membrane of a triarene unit copolymer structure and a method for preparing the same

Abstract

The application discloses a kind of triphenyl unit copolymer structure's basic anion exchange membrane and preparation method thereof, biphenyl, m-triphenyl and 1,2-diphenyl ethane are dissolved in first organic solvent and strong oxidizing acid and piperidone are sequentially added to carry out polycondensation reaction, after reaction, the reaction product is quenched, washed, dried, and solid powder is obtained;The solid powder is dissolved in second organic solvent and potassium carbonate and methyl iodide are added, and the reaction is carried out in dark at room temperature, after reaction, the reaction product is washed, dried, and polymer powder is obtained;The polymer powder is dissolved in second organic solvent to obtain casting liquid, the casting liquid is cast into film, and the triphenyl unit copolymer structure's basic anion exchange membrane is obtained.The triphenyl unit copolymer structure's basic anion exchange membrane has strong mechanical strength, high ionic conductivity and high chemical stability.

Description

Technical Field

[0001] This invention belongs to the field of basic anion exchange membranes, specifically relating to a basic anion exchange membrane with a triaromatic unit copolymer structure and its preparation method. Background Technology

[0002] With the escalating global energy trade crisis and the deepening of the concept of green and sustainable development, green and efficient new energy sources have received widespread attention and research worldwide. Among them, hydrogen energy has garnered significant attention due to its efficient energy conversion and the clean and green nature of its byproducts. Proton exchange membrane fuel cells (PEMFCs), as a low-temperature fuel cell device that directly converts hydrogen energy into electrical energy, have been widely used in mobile energy systems. However, PEMFCs suffer from high overall costs due to the long-term foreign monopoly on proton exchange membranes and the necessity of using precious metal catalysts. In contrast, alkaline anion exchange membrane fuel cells (AEMFCs), also a type of low-temperature fuel cell, can achieve faster oxygen reduction reaction kinetics under alkaline conditions. The choice of catalyst is no longer limited to precious metal catalysts, and in non-strongly acidic environments, both the electro-oxidation of hydrogen and the electro-reduction of oxygen are excellent, making them the primary alternative to PEMFCs. However, as a crucial component of AEMFCs, alkaline anion exchange membranes still face significant challenges, such as anion conductivity being much lower than proton conductivity and mechanical and chemical stability issues. Therefore, the development of alkaline anion exchange membranes with excellent overall performance is becoming increasingly urgent. Summary of the Invention

[0003] To address the problems existing in the prior art, the present invention provides a basic anion exchange membrane with a triaromatic unit copolymer structure and its preparation method. The basic anion exchange membrane with the triaromatic unit copolymer structure has strong mechanical strength, high ionic conductivity and high chemical stability.

[0004] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution:

[0005] A method for preparing a basic anion exchange membrane with a triaromatic unit copolymer structure, comprising:

[0006] Biphenyl, m-terphenyl and 1,2-diphenylethane were dissolved in a first organic solvent and a strong oxidizing acid and piperidinone were added sequentially to carry out a polycondensation reaction. After the reaction was completed, the reaction product was quenched, washed and dried to obtain a solid powder.

[0007] The solid powder was dissolved in a second organic solvent and potassium carbonate and iodomethane were added. The reaction was carried out at room temperature in the dark. After the reaction was completed, the reaction product was washed and dried to obtain polymer powder.

[0008] The polymer powder is dissolved in a second organic solvent to obtain a casting solution, which is then cast into a membrane to obtain an alkaline anion exchange membrane with a triaromatic unit copolymer structure.

[0009] Furthermore, the amount of biphenyl accounts for 30% to 70% of the total amount of the meta-terphenyl, 1,2-diphenylethane and biphenyl;

[0010] The volume ratio of the first organic solvent to the total mass of the biphenyl, m-terphenyl, and 1,2-diphenylethane is 1.5 ml:(0.2 g to 0.3 g);

[0011] The volume ratio of the first organic solvent to the strong oxidizing acid is (1-1.5):1;

[0012] The ratio of the amount of piperidinone to the total amount of the amounts of m-terphenyl, 1,2-diphenylethane and biphenyl is (1-1.5):1.

[0013] Furthermore, the reaction temperature of the polycondensation reaction is 0℃~8℃, and the reaction time is 6h~12h.

[0014] Furthermore, when preparing the polymer powder, the mass ratio of the second organic solvent to the mass of the solid powder is (40-60):1;

[0015] The ratio of the amount of iodomethane to the total amount of the amounts of m-terphenyl, 1,2-diphenylethane and biphenyl is (1.5-2):1;

[0016] The potassium carbonate accounts for 20% to 30% of the total mass of the m-terphenyl, 1,2-diphenylethane, and biphenyl.

[0017] Furthermore, the mass fraction of the casting liquid is 7% to 10%.

[0018] Furthermore, the casting temperature is 80℃~90℃.

[0019] Furthermore, the first organic solvent is dichloromethane or trichloromethane;

[0020] The second organic solvent is dimethyl sulfoxide.

[0021] Further, the strong oxidizing acid is trifluoroacetic acid and trifluoromethanesulfonic acid, and the volume ratio of trifluoroacetic acid to trifluoromethanesulfonic acid is (0.1~0.15):1.

[0022] Furthermore, the piperidone is N-4-methylpiperidone.

[0023] A basic anion exchange membrane with a triaromatic unit copolymer structure is prepared using the method described above.

[0024] Compared with the prior art, the present invention has at least the following beneficial effects:

[0025] This invention involves dissolving three aromatic monomers in an organic solvent and then chemically crosslinking them using piperidinone at low temperature. The introduction of biphenyl units improves the mechanical strength and microphase separation structure of the membrane, while the steric hindrance of the piperidinium structure protects the anion exchange sites under alkaline conditions. Compared with existing anion exchange membranes, this invention is the first to produce a tri-aromatic unit copolymer anion exchange membrane, improving its mechanical strength and chemical stability. The alkaline anion exchange membrane prepared by this invention is dense, transparent, has high ion exchange capacity, good thermal stability, and high mechanical strength, realizing the development of polymer ion exchange membranes with high conductivity and strong alkali resistance.

[0026] This invention directly polycondenses monomers using piperidine functional groups, and combines the excellent heat resistance, chemical stability, and mechanical strength of the main chain itself. It also reduces the influence of the Hoffmann effect from the perspective of steric hindrance, and optimizes the membrane-forming process for solvent evaporation in solution. This results in a type of polymer anion exchange membrane with strong mechanical strength, good chemical stability, stable heat resistance, and high ion exchange capacity.

[0027] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the specific embodiments of the present invention, the drawings used in the description of the specific embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0029] Figure 1 In the figure, (a) is a physical picture of the anion exchange membrane prepared in the comparative example, and (b), (c) and (d) are physical pictures of the triaromatic unit copolymer anion exchange membranes prepared in Example 1, Example 2 and Example 3, respectively.

[0030] Figure 2 In the image, (e) is a 400 nm planar scanning electron microscope image of the anion exchange membrane prepared in the comparative example, and (f), (g) and (h) are 400 nm planar scanning electron microscope images of the triaromatic unit copolymer anion exchange membranes prepared in Examples 1, 2 and 3, respectively.

[0031] Figure 3 In the figure, (a) is an atomic force microscope 3D image of the anion exchange membrane prepared in the comparative example, and (b), (c) and (d) are atomic force microscope 3D images of the triaromatic unit copolymer anion exchange membranes prepared in Examples 1, 2 and 3, respectively.

[0032] Figure 4 The graph shows the ionic conductivity of the triaromatic unit copolymer anion exchange membrane.

[0033] Figure 5 The diagram shows the mechanical tensile properties of the triaromatic unit copolymer anion exchange membrane.

[0034] Figure 6 Thermogravimetric curve of a triaromatic unit copolymer anion exchange membrane;

[0035] Figure 7 The battery power diagram shows the triaromatic unit copolymer anion exchange membrane under a platinum-carbon catalyst.

[0036] Figure 8 In the figures, (a) is the NMR spectrum of the first step polymerization product of the comparative example, (b) is the NMR spectrum of the second step quaternization reaction product of the comparative example, (c) is the NMR spectrum of the first step polymerization product of Example 1, and (d) is the NMR spectrum of the second step quaternization reaction product of Example 1.

[0037] Figure 9 The infrared spectrum at 400 nm is that of a triaromatic unit copolymer anion exchange membrane.

[0038] Figure 10 This is a flowchart illustrating the synthesis process of a triaromatic unit copolymer anion exchange membrane. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] Example 1

[0041] 1) Weigh 1.5g of m-terphenyl, 0.73g of 1,2-diphenylethane and 0.7g of biphenyl, and dissolve them completely in 14.65mL of dichloromethane. Use mechanical stirring at 240bpm and wait for 10min. Then add 1.7mL of N-4-methylpiperidone and continue stirring thoroughly. The solution will turn into a clear light yellow color.

[0042] 2) Gradually lower the temperature to 0℃, add 15mL of trifluoromethanesulfonic acid (TFSA) and 2.25mL of trifluoroacetic acid (TFA), react for 12h, and after the reaction is completed, the solution is dark brown and relatively viscous;

[0043] 3) The reaction product obtained in the previous step was poured into deionized water to quench the reaction. The mixture was mechanically stirred at high speed to break up the viscous polymer. Then it was washed with deionized water 8 times until neutral and dried at 60°C for 12 hours to obtain a solid powder.

[0044] 4) Weigh 2g of the solid powder obtained in the previous step and dissolve it in 80mL of dimethyl sulfoxide. After it is completely dissolved, keep the reaction system in the dark and add 0.4g of potassium carbonate and 1.44mL of iodomethane. React at room temperature for 36h.

[0045] 5) The reaction product obtained in the previous step was extracted with ethyl acetate (volume ratio 1:2), and washed 4 times with deionized water to obtain the functionalized polymer. The polymer was dried at 60℃ for 12h to obtain the quaternized polymer powder.

[0046] 6) Weigh 1.2g of the polymer powder from the previous step, dissolve it in dimethyl sulfoxide, and prepare a casting solution (precursor solution) with a mass fraction of 10%. Stir magnetically, sonicate until the solution is clear, pour it into a mold (glass plate), and slowly evaporate the solvent at 80℃ to obtain an alkaline anion exchange membrane with a triaromatic unit copolymer structure.

[0047] Example 2

[0048] 1) Weigh 1.5g of m-terphenyl, 0.73g of 1,2-diphenylethane and 1.6g of biphenyl, and dissolve them completely in 23mL of dichloromethane. Stir mechanically at 240bpm and wait for 10min. Then add 2.85mL of N-4-methylpiperidone and continue stirring thoroughly. The solution will turn into a clear light yellow.

[0049] 2) Gradually lower the temperature to about 6℃, slowly add 17.7mL of trifluoromethanesulfonic acid (TFSA) and 2.2mL of trifluoroacetic acid (TFA), react for 8 hours, and after the reaction is completed, the solution is dark brown and relatively viscous;

[0050] 3) The reaction product obtained in the previous step was poured into deionized water to quench the reaction. The mixture was mechanically stirred at high speed to break up the viscous polymer. Then it was washed with deionized water 8 times until neutral and dried at 60°C for 12 hours to obtain a solid powder.

[0051] 4) Weigh 2g of the solid powder obtained in the previous step and dissolve it in 100mL of dimethyl sulfoxide. After it is completely dissolved, keep the reaction system in the dark, add 0.5g of potassium carbonate and 2.28mL of iodomethane, and react at room temperature for 36h.

[0052] 5) The reaction product obtained in the previous step was extracted with ethyl acetate (volume ratio 1:2), and washed 4 times with deionized water to obtain the functionalized polymer. The polymer was dried at 60℃ for 12h to obtain the quaternized polymer powder.

[0053] 6) Weigh 1.2g of the polymer powder from the previous step, dissolve it in dimethyl sulfoxide to prepare a precursor solution with a mass fraction of 8%, stir magnetically, sonicate until the solution is clear, pour it onto a glass plate, and slowly evaporate the solvent at 85℃ to obtain an alkaline anion exchange membrane with a triaromatic unit copolymer structure.

[0054] Example 3

[0055] 1) Weigh 1.5g of m-terphenyl, 0.73g of 1,2-diphenylethane and 3.773g of biphenyl, and dissolve them completely in 45mL of dichloromethane. Use mechanical stirring at 240bpm and wait for 10min. Then add 5.93mL of N-4-methylpiperidone and continue stirring thoroughly. The solution will turn into a clear light yellow.

[0056] 2) Gradually lower the temperature to about 8°C, slowly add 30 mL of trifluoromethanesulfonic acid (TFSA) and 3 mL of trifluoroacetic acid (TFA), react for 6 hours, and after the reaction is completed, the solution will be dark brown and relatively viscous;

[0057] 3) The reaction product obtained in the previous step was poured into deionized water to quench the reaction. The mixture was mechanically stirred at high speed to break up the viscous polymer. Then it was washed with deionized water 8 times until neutral and dried at 60°C for 12 hours to obtain a solid powder.

[0058] 4) Weigh 2g of the solid powder obtained in the previous step and dissolve it in 120mL of dimethyl sulfoxide. After it is completely dissolved, keep the reaction system in the dark, add 0.6g of potassium carbonate and 4.48mL of iodomethane, and react at room temperature for 36h.

[0059] 5) The reaction product obtained in the previous step was washed in ethyl acetate and washed 4 times with deionized water to obtain the functionalized polymer. The polymer was dried at 60°C for 12 hours to obtain the quaternized polymer powder.

[0060] 6) Weigh 0.7g of the polymer powder from the previous step, dissolve it in dimethyl sulfoxide to prepare a precursor solution with a mass fraction of 7%, stir magnetically, sonicate until the solution is clear, pour it onto a glass plate, and slowly evaporate the solvent at 90℃ to obtain an alkaline anion exchange membrane with a triaromatic unit copolymer structure.

[0061] Example 4

[0062] 1) Weigh 1.5g of m-terphenyl, 0.73g of 1,2-diphenylethane and 3.1g of biphenyl, and dissolve them completely in 40mL of dichloromethane. Use mechanical stirring at 240bpm and wait for 10min. Then add 4.1mL of N-4-methylpiperidone and continue stirring thoroughly. The solution will turn into a clear light yellow.

[0063] 2) Gradually lower the temperature to about 3°C, slowly add 36 mL of trifluoromethanesulfonic acid (TFSA) and 4.32 mL of trifluoroacetic acid (TFA), react for 10 h, and after the reaction is completed, the solution is dark brown and relatively viscous;

[0064] 3) The reaction product obtained in the previous step was poured into deionized water to quench the reaction. The mixture was mechanically stirred at high speed to break up the viscous polymer. Then, it was washed with deionized water 8 times until neutral and dried at 60°C for 12 hours to obtain a solid powder.

[0065] 4) Weigh 2g of the solid powder obtained in the previous step and dissolve it in 100mL of dimethyl sulfoxide. After it is completely dissolved, keep the reaction system in the dark, add 0.55g of potassium carbonate and 3.45mL of iodomethane, and react at room temperature for 36h.

[0066] 5) The reaction product obtained in the previous step was extracted with ethyl acetate (volume ratio 1:2), and washed 4 times with deionized water to obtain the functionalized polymer. The polymer was dried at 60℃ for 12h to obtain the quaternized polymer powder.

[0067] 6) Weigh 0.7g of the polymer powder from the previous step, dissolve it in dimethyl sulfoxide to prepare a precursor solution with a mass fraction of 9%, stir magnetically, sonicate until the solution is clear, pour it onto a glass plate, and slowly evaporate the solvent at 80℃ to obtain an alkaline anion exchange membrane with a triaromatic unit copolymer structure.

[0068] Example 5

[0069] 1) Weigh 1.5g of m-terphenyl, 0.73g of 1,2-diphenylethane and 2.8g of biphenyl, and dissolve them completely in 32mL of dichloromethane. Use mechanical stirring at 240bpm and wait for 10min. Then add 4.2mL of N-4-methylpiperidone and continue stirring until the solution turns clear and light yellow.

[0070] 2) Gradually lower the temperature to about 4℃, slowly add 26.7mL of trifluoromethanesulfonic acid (TFSA) and 3.47mL of trifluoroacetic acid (TFA), react for 12h, and after the reaction is completed, the solution is dark brown and relatively viscous;

[0071] 3) The reaction product obtained in the previous step was poured into deionized water to quench the reaction. The mixture was mechanically stirred at high speed to break up the viscous polymer. Then it was washed with deionized water 8 times until neutral and dried at 60°C for 12 hours to obtain a solid powder.

[0072] 4) Weigh 2g of the solid powder obtained in the previous step and dissolve it in 110mL of dimethyl sulfoxide. After it is completely dissolved, keep the reaction system in the dark and add 0.45g of potassium carbonate and 3.3mL of iodomethane. React at room temperature for 36h.

[0073] 5) The reaction product obtained in the previous step was extracted with ethyl acetate (volume ratio 1:2), and washed 4 times with deionized water to obtain the functionalized polymer. The polymer was dried at 60℃ for 12h to obtain the quaternized polymer powder.

[0074] 6) Weigh 0.7g of the polymer powder from the previous step, dissolve it in dimethyl sulfoxide to prepare a precursor solution with a mass fraction of 8%, stir magnetically, sonicate until the solution is clear, pour it onto a glass plate, and slowly evaporate the solvent at 80℃ to obtain an alkaline anion exchange membrane with a triaromatic unit copolymer structure.

[0075] Comparative Example

[0076] 1) Weigh 1.5g of m-terphenyl and 0.73g of 1,2-diphenylethane, and dissolve them completely in 18mL of dichloromethane. Stir mechanically at 240bpm and wait for 10min. Then add 1.2mL of N-4-methylpiperidone and continue stirring thoroughly. The solution will turn into a clear light yellow color.

[0077] 2) Gradually lower the temperature to about 1°C, slowly add 20 mL of trifluoromethanesulfonic acid (TFSA) and 2 mL of trifluoroacetic acid (TFA), and react for 12 h. After the reaction is complete, the solution will be dark brown and quite viscous.

[0078] 3) The reaction product obtained in the previous step was poured into deionized water to quench the reaction. The mixture was mechanically stirred at high speed to break up the viscous polymer. Then it was washed with deionized water 8 times until neutral and dried at 60°C for 12 hours to obtain a solid powder.

[0079] 4) Weigh 1g of the solid powder obtained in the previous step and dissolve it in 85mL of dimethyl sulfoxide. After it is completely dissolved, keep the reaction system in the dark, add 400mg of potassium carbonate and 1.4mL of iodomethane, and react at room temperature for 36h.

[0080] 5) The reaction product obtained in the previous step was extracted with ethyl acetate (volume ratio 1:2), and washed 4 times with deionized water to obtain the functionalized polymer. The polymer was dried at 60℃ for 12h to obtain the quaternized polymer powder.

[0081] 6) Weigh 0.7g of the polymer powder from the previous step, dissolve it in dimethyl sulfoxide to prepare a precursor solution with a mass fraction of 8%, stir magnetically, sonicate until the solution is clear, pour it into a petri dish / glass plate, and slowly evaporate the solvent at 60℃ to obtain anion exchange membrane.

[0082] The basic anion exchange membranes with triaromatic unit copolymer structures prepared in Examples 1, 2, and 3, as well as the anion exchange membrane prepared in the comparative example, were subjected to the following tests: scanning electron microscopy to observe the morphology, atomic force microscopy to observe the microphase separation structure, ionic conductivity testing, mechanical tensile testing, thermogravimetric analysis, and battery power testing. 1 The H NMR spectrum characterization and infrared spectroscopy characterization experiments are described below in conjunction with... Figures 1 to 9 A detailed analysis and explanation will be provided.

[0083] Figure 1 Physical images of the membranes from the comparative example, Example 1, Example 2, and Example 3 are shown. It can be seen that the membrane surface is smooth, transparent, and free of cracks. The four membranes meet the basic requirements of an alkaline anion exchange membrane.

[0084] Figure 2 Scanning electron microscope (SEM) images of the comparative example, Example 1, Example 2, and Example 3 are shown. In the 400 nm range, the membrane surface is basically smooth, without cracks or micropores. The four membranes meet the requirements of alkaline anion exchange membranes.

[0085] Figure 3 Atomic force microscopy images of the comparative example, Example 1, Example 2, and Example 3 are shown. Under the three-dimensional phase diagram, all four membranes showed good microphase separation structure. Among them, Example 1, Example 2, and Example 3 have more obvious microphase separation structure than the comparative example, which can provide channels for ion transport and thus improve the conductivity performance of the membrane.

[0086] The films prepared in Comparative Examples, Examples 1, 2, and 3 were mounted in a four-terminal probe conductivity test mold and tested using the AC impedance method at frequencies ranging from 100,000 Hz to 10 Hz. The resistance was obtained from the AC impedance diagram, and the conductivity at different temperatures was calculated using the formula: reference electrode spacing / (polymer cross-sectional area * resistance) = conductivity. The results are shown below. Figure 4As shown, all four membranes exhibit high ionic conductivity. Meanwhile, compared to the comparative examples, Examples 1, 2, and 3 all show higher ionic conductivity. Furthermore, PMDBP-30 exhibits higher ionic conductivity than the other three, indicating that it possesses the best ionic conductivity performance. It should be noted that... Figure 4 In this context, PMDBP-30 represents the performance of the product prepared in Example 1, PMDBP-50 represents the performance of the product prepared in Example 2, PMDBP-70 represents the performance of the product prepared in Example 3, and PMDP represents the performance of the comparative example.

[0087] Figure 5 The mechanical tensile properties test graphs of the comparative example, Example 1, Example 2, and Example 3 are shown. All four membranes exhibited good mechanical tensile properties (tensile stress greater than 25 MPa), meeting the conditions for long-term operation in batteries. Compared to the comparative example, Examples 1, 2, and 3 all exhibited higher tensile stress. It should be noted that... Figure 5 In this context, PMDBP-30 represents the performance of the product prepared in Example 1, PMDBP-50 represents the performance of the product prepared in Example 2, PMDBP-70 represents the performance of the product prepared in Example 3, and PMDP represents the performance of the comparative example.

[0088] Figure 6 Thermal stability tests of the comparative examples, Example 1, Example 2, and Example 3 are presented. All four films exhibited good heat resistance, with a significant decrease in mass at 300°C, meeting the requirements for long-term operation at 80°C–100°C when the films are installed in batteries. It should be noted that... Figure 6 In this context, PMDBP-30 represents the performance of the product prepared in Example 1, PMDBP-50 represents the performance of the product prepared in Example 2, PMDBP-70 represents the performance of the product prepared in Example 3, and PMDP represents the performance of the comparative example.

[0089] Figure 7 Performance graphs of alkaline anion exchange membrane fuel cells from Comparative Example, Example 1, Example 2, and Example 3 are shown. Using platinum-carbon as a catalyst, the Comparative Example exhibits a lower power density compared to Examples 1, 2, and 3, while Examples 1, 2, and 3 all have power densities greater than 70 Mw / cm³. 2 This indicates that all of them have good working performance. Among them, PMDBP-50 showed the highest power density, indicating that it has the best electrochemical performance, ensuring that the membrane can operate at a higher power.

[0090] The membranes prepared in the comparative example and Example 1 were immersed in 0.1M sodium hydroxide solution for 72 hours for ion exchange to obtain anion exchange membranes in the form of hydroxide ions. The anion exchange membranes in the form of hydroxide ions were then placed in anion exchange solution at room temperature for 12–48 hours to complete the ion exchange. The chemical crosslinking and functionalization of the polymer benzene ring were quantitatively characterized using an AVANCE III HD 600MHz spectrometer, with a resonance frequency of 600MHz. During the experiment, a small amount of the sample was dissolved in deuterated dimethyl sulfoxide, and the sample was acquired using a nuclear magnetic resonance spectrometer. 1 The 1H NMR spectrum, with tetramethylsilane (TMS) as an internal standard, yielded the following results: Figure 8 As shown, (b) is the NMR spectrum of the product from the first step of the reaction, with the positions of each characteristic peak corresponding to the structure diagram. (d) is the NMR spectrum of the product from the quaternization reaction using iodomethane, with each characteristic peak corresponding to the structure diagram above.

[0091] Figure 9 Infrared spectral tests of the comparative example, Example 1, Example 2, and Example 3 are shown. All four films showed corresponding infrared characteristic peaks, further demonstrating the characterization of the reaction structure.

[0092] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing a basic anion exchange membrane with a triaromatic unit copolymer structure, characterized in that, include: Biphenyl, m-terphenyl, and 1,2-diphenylethane were dissolved in a first organic solvent. Piperidinone was added first and the mixture was stirred thoroughly. Then, the temperature was lowered to 0°C to 8°C, and a strong oxidizing acid was added to carry out a polycondensation reaction for 6 to 12 hours. After the reaction was completed, the reaction product was quenched, washed, and dried to obtain a solid powder. The amount of biphenyl was 30% to 70% of the total amount of m-terphenyl, 1,2-diphenylethane, and biphenyl. The solid powder was dissolved in a second organic solvent and potassium carbonate and iodomethane were added. The reaction was carried out at room temperature in the dark. After the reaction was completed, the reaction product was washed and dried to obtain polymer powder. The polymer powder is dissolved in a second organic solvent to obtain a casting solution, which is then cast into a membrane to obtain an alkaline anion exchange membrane with a triaromatic unit copolymer structure.

2. The method for preparing a basic anion exchange membrane with a triaromatic unit copolymer structure according to claim 1, characterized in that, The volume ratio of the first organic solvent to the total mass of the biphenyl, m-terphenyl, and 1,2-diphenylethane is 1.5 ml: (0.2 g ~ 0.3 g). The volume ratio of the first organic solvent to the strong oxidizing acid is (1~1.5):1; The ratio of the amount of piperidinone to the total amount of the amounts of m-terphenyl, 1,2-diphenylethane and biphenyl is (1~1.5):

1.

3. The method for preparing a basic anion exchange membrane with a triaromatic unit copolymer structure according to claim 1, characterized in that, When preparing the polymer powder, the mass ratio of the second organic solvent to the mass of the solid powder is (40~60):1; The ratio of the amount of iodomethane to the total amount of the amounts of m-terphenyl, 1,2-diphenylethane and biphenyl is (1.5~2):1; The potassium carbonate accounts for 20% to 30% of the total mass of the m-terphenyl, 1,2-diphenylethane and biphenyl.

4. The method for preparing a basic anion exchange membrane with a triaromatic unit copolymer structure according to claim 1, characterized in that, The mass fraction of the casting liquid is 7% to 10%.

5. The method for preparing a basic anion exchange membrane with a triaromatic unit copolymer structure according to claim 1, characterized in that, The casting temperature is 80℃~90℃.

6. The method for preparing a basic anion exchange membrane with a triaromatic unit copolymer structure according to claim 1, characterized in that, The first organic solvent is dichloromethane or trichloromethane; The second organic solvent is dimethyl sulfoxide.

7. The method for preparing a basic anion exchange membrane with a triaromatic unit copolymer structure according to claim 1, characterized in that, The strong oxidizing acid is trifluoroacetic acid and trifluoromethanesulfonic acid, and the volume ratio of trifluoroacetic acid to trifluoromethanesulfonic acid is (0.1~0.15):

1.

8. The method for preparing a basic anion exchange membrane with a triaromatic unit copolymer structure according to claim 1, characterized in that, The piperidone is N-4-methylpiperidone.

9. A basic anion exchange membrane with a triaromatic unit copolymer structure, characterized in that, It is prepared by the preparation method according to any one of claims 1 to 8.

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