A six-arm star-shaped branched polyarylpipeidine anion exchange membrane, a preparation method and application thereof

Abstract

A six-arm star branched polyaryl piperidine anion exchange membrane, a preparation method and application belong to the field of alkaline fuel cells and water electrolysis. The six-arm star branched polymer main chain is prepared by introducing tri(4-carbazol-9-ylphenyl) amine with six branching sites as a branching unit into the polymer main chain, and performing a Friedel-Crafts alkylation copolymerization with p-terphenyl and N-methyl-4-piperidone under the catalysis of a super acid; then the piperidine ring in the main chain is quaternized by a Mayr reaction to obtain the target anion exchange membrane. The star branched structure of the application significantly increases the free volume in the membrane, and induces the formation of a microphase separation structure with larger size and stronger connectivity; the anion exchange membrane has higher hydroxyl ion conductivity, excellent alkali stability, good mechanical properties and outstanding fuel cell and water electrolysis performance, and has a broad application prospect in the field of electrochemical energy devices.

Description

Technical Field

[0001] This invention belongs to the field of anion exchange membrane technology, and relates to a six-armed star-shaped branched carbazole-based anion exchange membrane, its preparation method, and its application in fuel cells and water electrolysis. Background Technology

[0002] Anion exchange membrane fuel cells (AEMFCs) are considered key to next-generation high-efficiency clean energy conversion technologies due to their advantages such as the ability to use non-precious metal catalysts (e.g., nickel, cobalt, iron), fast reaction kinetics, and wide fuel adaptability. Anion exchange membrane electrolysis of water (AEMWE) has also received widespread attention in recent years because it can achieve efficient hydrogen production at low cost and with non-precious metal catalysts, and can operate under neutral or alkaline conditions, avoiding equipment corrosion problems in strong acid environments. As the core component of the aforementioned electrochemical devices, the anion exchange membrane (AEM) plays a crucial role in conducting hydroxide ions (OH-). - ) or chloride ions (Cl - It plays a crucial role in isolating fuel and oxidant, and its performance directly determines the energy efficiency, power density, and service life of the battery or electrolyzer.

[0003] However, traditional linear anion exchange membranes often face a trade-off between conductivity and stability. On the one hand, improving ionic conductivity usually requires increasing the ion exchange capacity (IEC), but this leads to excessive water absorption and a sharp increase in swelling rate, severely damaging the membrane's dimensional stability and mechanical properties, and even causing structural damage. On the other hand, cationic groups (such as quaternary ammonium salts) are prone to Hoffmann elimination or nucleophilic substitution degradation in alkaline environments, resulting in the loss of ion exchange capacity. Constructing hydrophilic / hydrophobic microphase separation structures is an effective strategy to improve conductivity. By inducing the self-assembly of hydrophilic ion clusters and hydrophobic polymer backbones, continuous ion transport channels at the nanoscale can be formed, improving conductivity without significantly increasing IEC. However, the high molecular chain regularity and dense packing of linear polymer chains limit the permeability and connectivity of ion channels, making the construction of microphase separation structures often less than ideal.

[0004] Increasing the free volume within the membrane is another way to improve ion conduction. Free volume provides a wider "highway" for ion transport, reducing resistance to ion migration. Gao et al., in their paper "High-performance tetracyclic aromatic anion exchange membranes containing twisted binaphthyl for fuel cells," proposed using twisted binaphthyl units to increase the free volume within the membrane, achieving a conductivity of 135.25 mS / cm. -1However, this linear polymer structure does not provide good dimensional stability for the membrane, and its alkali stability is also insufficient. Therefore, developing a novel AEM that can simultaneously achieve high conductivity, high alkali stability, and good dimensional stability is a pressing technical challenge in this field. Summary of the Invention

[0005] This invention aims to improve the ion transport performance, dimensional stability, and chemical stability of anion exchange membranes, and provides a method for preparing a six-armed star-shaped branched carbazole-based anion exchange membrane. Tris(4-carbazole-9-ylphenyl)amine with six branching sites is introduced into the polymer backbone as a branching unit to construct a six-armed star-shaped branched structure. This structure significantly increases the free volume within the membrane, increases the interchain spacing, and induces the formation of a larger, more interconnected hydrophilic ion cluster network, promoting microphase separation. The prepared membrane exhibits extremely high ionic conductivity, excellent alkaline stability, and good dimensional stability, demonstrating excellent performance in fuel cells, water electrolysis, and neutral flow batteries.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A six-armed star-shaped branched carbazole-based anion exchange membrane is disclosed. The membrane uses ether-free arylpiperidine as the main chain, iodomethane as the quaternizing agent, and tris(4-carbazole-9-ylphenyl)amine as the branching functional unit. Six ether-free arylpiperidine branches are connected by tris(4-carbazole-9-ylphenyl)amine to construct a star-shaped topology, inducing microphase separation and reducing chain stacking to increase the free volume within the membrane. Furthermore, the introduced six-armed branching structure helps increase the free volume of the polymer, promoting microphase separation. The polymer structural formula is as follows: Where x is the molar percentage of tris(4-carbazole-9-ylphenyl)amine unit to aryl monomer, and the value of x ranges from 1% to 3%.

[0007] A method for preparing a six-armed star-shaped branched carbazole-based anion exchange membrane includes the following steps: Step (1) Synthesis of a six-armed star-shaped branched polymer: p-terphenyl, tri(4-carbazole-9-ylphenyl)amine and N-methyl-4-piperidinone are dissolved in organic solvent A. Under ice bath conditions of 0-5℃, a mixture of trifluoroacetic acid and trifluoromethanesulfonic acid is slowly added. Tri(4-carbazole-9-ylphenyl)amine, p-terphenyl and N-methyl-4-piperidinone undergo Friedel-Crafts alkylation reaction for 4-6 hours until viscous. The viscous liquid is slowly poured into solvent A for precipitation to obtain a yellow polymer A. The polymer A is washed until neutral and then vacuum dried to obtain a six-armed star-shaped branched polymer.

[0008] The molar ratio of p-terphenyl to N-methyl-4-piperidinone in step (1) is 1:1.1-1.3; In step (1), the molar ratio of tris(4-carbazole-9-ylphenyl)amine to p-terphenyl is 0.01:1 to 0.03:1; The molar ratio of trifluoroacetic acid to p-terphenyl in step (1) is 1-4:1; The molar ratio of trifluoromethanesulfonic acid to p-terphenyl in step (1) is 4-10:1.

[0009] In step (1), solvent A is selected from methanol, ethanol, and alkaline solution.

[0010] The organic solvent A mentioned in step (1) is selected from one of dichloromethane, chloroform, and tetrahydrofuran.

[0011] In step (1), the vacuum drying temperature is 50-80 ℃ and the time is 24-48 h.

[0012] Step (2) Quaternization treatment of the six-armed star-shaped branched polymer obtained in step (1): Dissolve the six-armed star-shaped branched polymer obtained in step (1) in organic solvent B, add potassium carbonate and iodomethane, and carry out the six-armed star-shaped branched polymer and iodomethane in the dark for 24-48 hours at 20-40℃; After the reaction is completed, add the reaction solution to solvent B to obtain a white precipitate, wash the white precipitate with deionized water, and then vacuum dry to obtain the quaternized polymer.

[0013] In step (2), for every 20 ml of organic solvent B, add 1-1.2 g of six-armed star-shaped branched polymer, 1.2-1.4 g of potassium carbonate, and 0.6-0.7 ml of iodomethane. The organic solvent B mentioned in step (2) is dimethyl sulfoxide, N-methylpyrrolidone, or N,N-dimethylformamide.

[0014] The solvent B mentioned in step (2) is one of ethyl acetate, diethyl ether, or tetrahydrofuran.

[0015] In step (2), the vacuum drying temperature is 50-80 ℃ and the time is 24-48 h. Step (3) Casting: Dissolve the quaternized polymer that has been reacted in step (2) in the organic solvent B described in step (2) to prepare a casting solution of 3-8 wt%, transfer it into a casting glass plate, place it on a constant temperature heating table to cast the film, and obtain the film material after the solvent has completely evaporated. In step (3), the addition ratio of the quaternized polymer to organic solvent B is 0.6-1.6 g: 20 mL; In step (3), the constant temperature heating table for drying the film formed by casting is 40-70℃ and the time is 24-48 hours.

[0016] Step (4) Alkalization: Immerse the membrane in an alkaline solution for 24-48 hours at room temperature to perform ion exchange, and then wash it with deionized water to obtain anion exchange membrane in the form of hydroxide ions.

[0017] The alkaline solution mentioned in step (4) is a 1-2 M sodium hydroxide or potassium hydroxide solution.

[0018] An application of a six-armed star-shaped branched carbazole-based anion exchange membrane, which is used as an anion exchange membrane in fuel cells and water electrolysis.

[0019] Effects and benefits of the present invention: This invention designs and prepares a novel six-armed star-shaped branched carbazole-based anion exchange membrane for use in fuel cells and water electrolysis through superacid-catalyzed polycondensation and quaternization reactions. Using ether-free polyarylpiperidine as the main chain, tris(4-carbazole-9-ylphenyl)amine is introduced as a six-branched functional monomer. The tris(4-carbazole-9-ylphenyl)amine monomer connects six branches, which can induce the formation of a larger, more clearly defined, and more interconnected hydrophilic ion cluster network, promoting microphase separation. Figure 2 This process weakens the main chain stacking, increases the free volume within the membrane, reduces the resistance to hydroxide ion transport, and gives the membrane a higher ionic conductivity.

[0020] The anion exchange membrane prepared by this method exhibits excellent battery performance. In Example 1, the peak power density of this membrane fuel cell reached 1.95 W·cm³ at 80°C and a back pressure of 1.3 bar. -2 The water electrolysis performance reached 9.51 A·cm⁻¹ at 80℃ and 1 M KOH. -2 @ 2.0 V, far superior to traditional linear structure membranes. Attached Figure Description

[0021] Figure 1 The hydroxide conductivity of the anion exchange membranes prepared in Example 1 and Comparative Example 1 of this invention is shown at different temperatures.

[0022] Figure 2 The images provided are transmission electron microscope images of Comparative Case 1, Implementation Case 1, Implementation Case 2, and Implementation Case 3 of this invention.

[0023] Figure 3 The performance curves (polarization curve and power density curve) of the anion exchange membrane prepared in Example 1 of this invention in an H2-O2 fuel cell are shown.

[0024] Figure 4The polarization curve of the anion exchange membrane prepared in Example 1 of this invention is shown in the water electrolysis test. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to specific implementation examples, but the implementation of the present invention is not limited thereto.

[0026] Implementation Case 1 (1) Main chain synthesis; Weigh 1.17 g of p-terphenyl and 0.11 g of tris(4-carbazole-9-ylphenyl)amine, measure 0.7 mL of N-methyl-4-piperidinone, and add them to 2.5 mL of dichloromethane. After bathing in an ice bath for 10 minutes, slowly add a mixed solution of 0.4 mL of trifluoroacetic acid and 6 mL of trifluoromethanesulfonic acid dropwise using a dropping funnel while in an ice bath. React for 4 hours under ice bath conditions to obtain a viscous liquid. Slowly pour the liquid into a 1 M NaOH solution to precipitate, obtaining a yellow polymer A. Filter and wash with deionized water until neutral. Dry in a vacuum drying oven at 50 °C for 48 hours to obtain a six-armed star-shaped branched polymer.

[0027] (2) Quaternization; Take 2.0 g of the six-armed star-shaped branched polymer obtained in step (2), add it to 40 mL of dimethyl sulfoxide, dissolve to form a transparent solution, then add 2.4 g of potassium carbonate and 1.2 mL of iodomethane, and react at 40 °C in the dark for 24 hours. After the reaction is complete, slowly pour the reaction solution into ethyl acetate to precipitate, filter and wash three times with deionized water, and dry in a vacuum drying oven at 50 °C for 48 hours to obtain the quaternized polymer.

[0028] (3) Casting film; Take the 1.0 quaternary ammonium polymer obtained in step (2), dissolve it in 20 mL of dimethyl sulfoxide, and prepare a 5 wt% casting solution. After filtering the casting solution, pour it into a clean glass plate of 5 cm × 5 cm, and place it on a constant temperature heating table at 40 ℃ to dry for 48 hours to obtain the membrane material.

[0029] (4) Alkalization; The membrane was immersed in 1 M NaOH solution for 48 hours to allow for sufficient ion exchange. Then, it was repeatedly rinsed with deionized water to remove the residual alkali solution from the membrane surface, resulting in an anion exchange membrane in the form of hydroxide ions.

[0030] Tests showed that the anion exchange membrane prepared in this embodiment had a hydroxide ion conductivity of 155.7 mS / cm at 80°C. -1 ( Figure 1After immersion in a 2 M NaOH solution at 80℃ for 2000 h, the conductivity retention rate was 89.1%. In H2-O2 fuel cell testing, at 80℃ and a back pressure of 1.3 bar, the peak power density reached 1.95 Wcm³. -2 ( Figure 3 In the water electrolysis test, under conditions of 80℃, 1 M KOH, and 2.0 V voltage, the current density was 9.51 Acm. -2 ( Figure 4 ).

[0031] Implementation Case 2 (1) Main chain synthesis; Weigh 1.14 g of p-terphenyl and 0.037 g of tris(4-carbazole-9-ylphenyl)amine, and measure 0.64 mL of N-methyl-4-piperidinone. Add these to 2.5 mL of chloroform. After 10 minutes at 2 °C, slowly add a mixed solution of 0.8 mL of trifluoroacetic acid and 4 mL of trifluoromethanesulfonic acid using a dropping funnel. React at 2 °C for 5 hours to obtain a viscous liquid. Slowly pour the liquid into a methanol solution to precipitate, obtaining a yellow polymer A. Filter and wash with deionized water until neutral. Dry in a vacuum drying oven at 65 °C for 36 hours to obtain a six-armed star-shaped branched polymer.

[0032] (2) Quaternization; Take 2.2 g of the six-armed star-shaped branched polymer obtained in step (1), add it to 40 mL of N-methylpyrrolidone, dissolve to form a transparent solution, then add 2.9 g of potassium carbonate and 1.3 mL of iodomethane, and react at 20 ℃ in the dark for 48 hours. After the reaction is complete, slowly pour the reaction solution into diethyl ether to precipitate, filter and wash three times with deionized water, and dry in a vacuum drying oven at 65 ℃ for 36 hours to obtain the quaternized polymer.

[0033] (3) Casting film; Take 0.6 g of the quaternized polymer obtained in step (2), dissolve it in 20 mL of N-methylpyrrolidone, and prepare a 3wt% casting solution. After filtering the casting solution, pour it into a clean glass plate of 5 cm × 5 cm, and place it on a constant temperature heating table at 55℃ to dry for 36 hours to obtain the membrane material.

[0034] (4) Alkalization; The membrane was immersed in 2 M KOH solution for 24 hours to allow for sufficient ion exchange. It was then repeatedly rinsed with deionized water to remove any residual alkali from the membrane surface, yielding an anion exchange membrane in hydroxide form. Tests showed that the anion exchange membrane prepared in this embodiment had a hydroxide ion conductivity of 123.3 mS / cm at 80°C. -1After immersion in a 2 M NaOH solution at 80℃ for 2000 h, the conductivity retention rate was 83.9%. In H2-O2 fuel cell testing, at 80℃ and a back pressure of 1.3 bar, the peak power density reached 1.73 Wcm³. -2 In the water electrolysis test, under conditions of 80℃, 1M KOH, and 2.0 V voltage, the current density was 7.14 Acm⁻¹. -2 .

[0035] Implementation Case 3 (1) Main chain synthesis; Weigh 1.13 g of p-terphenyl and 0.074 g of tris(4-carbazole-9-ylphenyl)amine, and measure 0.76 mL of N-methyl-4-piperidinone. Add these to 2.5 mL of tetrahydrofuran. After 10 minutes at 5 °C, slowly add a mixed solution of 1.6 mL of trifluoroacetic acid and 2.5 mL of trifluoromethanesulfonic acid using a dropping funnel. React at 5 °C for 6 hours to obtain a viscous liquid. Slowly pour the liquid into an ethanol solution to precipitate, obtaining a yellow polymer A. Filter and wash with deionized water until neutral. Dry in a vacuum drying oven at 80 °C for 24 hours to obtain a six-armed star-shaped branched polymer.

[0036] (2) Quaternization; Take 2.4 g of the quaternized polymer obtained in step (1), add it to 40 mL of N,N-dimethylformamide, dissolve to form a transparent solution, then add 3.4 g of potassium carbonate and 1.7 mL of iodomethane, and react at 30 ℃ in the dark for 36 hours. After the reaction is complete, slowly pour the reaction solution into tetrahydrofuran to precipitate, filter and wash three times with deionized water, and dry in a vacuum drying oven at 80 ℃ for 24 hours to obtain the quaternized polymer.

[0037] (3) Casting film; Take 1.6 g of the quaternized polymer obtained in step (2), dissolve it in 20 mL of N,N-dimethylformamide, and prepare an 8 wt% casting solution. After filtering the casting solution, pour it into a clean glass plate of 5 cm × 5 cm, place it on a 70℃ constant temperature heating table and dry it for 24 hours to obtain the membrane material.

[0038] (4) Alkalization; The membrane was immersed in 1 M KOH solution for 48 hours to allow for sufficient ion exchange. It was then repeatedly rinsed with deionized water to remove any residual alkali from the membrane surface, yielding an anion exchange membrane in hydroxide form. Tests showed that the anion exchange membrane prepared in this embodiment had a hydroxide ion conductivity of 137.9 mS / cm at 80°C. -1After immersion in a 2 M NaOH solution at 80℃ for 2000 h, the conductivity retention rate was 86.3%. In H2-O2 fuel cell testing, at 80℃ and a back pressure of 1.3 bar, the peak power density reached 1.42 Wcm³. -2 In the water electrolysis test, under conditions of 80℃, 1M KOH, and 2.0 V voltage, the current density was 5.32 Acm. -2 .

[0039] Comparison Case 1 (1) Main chain synthesis; Weigh 1.15 g of p-terphenyl, measure 0.7 mL of N-methyl-4-piperidinone, and add it to 2.5 mL of dichloromethane. After incubating in an ice bath for 10 minutes, slowly add a mixed solution of 0.4 mL of trifluoroacetic acid and 5 mL of trifluoromethanesulfonic acid dropwise using a dropping funnel while in an ice bath. React for 5 hours under ice bath conditions to obtain a viscous liquid. Slowly pour the liquid into a 1 M NaOH solution to precipitate, obtaining a yellow polymer A. Filter and wash with deionized water until neutral. Dry in a vacuum drying oven at 80 °C for 24 hours to obtain a linear polymer.

[0040] (2) Quaternization; Take 2.0 g of the linear polymer obtained in step (1), add it to 40 mL of dimethyl sulfoxide, dissolve to form a transparent solution, then add 2.4 g of potassium carbonate and 1.2 mL of iodomethane, and react at 40 °C in the dark for 48 hours. After the reaction is complete, slowly pour the reaction solution into ethyl acetate to precipitate, filter and wash three times with deionized water, and dry in a vacuum drying oven at 65 °C for 36 hours to obtain the quaternized polymer.

[0041] (3) Casting film; Take 1.0 g of the quaternized polymer obtained in step (2), dissolve it in 20 mL of dimethyl sulfoxide, and prepare a 5 wt% casting solution. After filtering the casting solution, pour it into a clean glass plate of 5 cm × 5 cm, and dry it in an oven at 65 ℃ for 36 hours to obtain the membrane material.

[0042] (4) Alkalization; The membrane was immersed in 1 M NaOH solution for 48 hours to allow for sufficient ion exchange. It was then repeatedly rinsed with deionized water to remove any residual alkali from the membrane surface, yielding an anion exchange membrane in hydroxide form. Tests showed that the anion exchange membrane prepared in this embodiment has a hydroxide ion conductivity of 110.1 mS / cm at 80°C. -1After immersion in a 2 M NaOH solution at 80℃ for 2000 h, the conductivity retention rate was 79.8%. In H2-O2 fuel cell testing, at 80℃ and a back pressure of 1.3 bar, the peak power density reached 1.15 Wcm³. -2 In the water electrolysis test, under conditions of 80℃, 1M KOH, and 2.0 V voltage, the current density was 2.81 Acm. -2 .

[0043] The above embodiments are merely illustrative of the implementation methods of the present invention, but should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the protection scope of the present invention.

Claims

1. A method for preparing a six-armed star-shaped branched polyarylpiperidine anion exchange membrane, characterized in that, Includes the following steps: Step (1) Synthesis of a six-armed star-shaped branched polymer: terphenyl, tris(4-carbazole-9-ylphenyl)amine, and N-methyl-4-piperidinone were dissolved in organic solvent A. Under ice bath conditions of 0-5°C, a mixture of trifluoroacetic acid and trifluoromethanesulfonic acid was added as a superacid. The tris(4-carbazole-9-ylphenyl)amine, terphenyl, and N-methyl-4-piperidinone were reacted for 4-6 hours until a viscous state was reached. The viscous liquid was slowly poured into solvent A to precipitate, yielding a yellow polymer A. The polymer A was washed until neutral and then vacuum dried to obtain a six-armed star-shaped branched polymer. Step (2) Quaternizes the six-armed star-shaped branched polymer obtained in step (1): The six-armed star-shaped branched polymer was dissolved in organic solvent B, potassium carbonate and iodomethane were added, and the reaction was carried out at 20-40℃ for 24-48 hours. After the reaction was completed, the reaction solution was added to solvent B to obtain a white precipitate. The white precipitate was washed with deionized water and dried under vacuum to obtain the quaternized polymer. Step (3) Casting: Dissolve the quaternized polymer in organic solvent B to prepare the casting solution, and dry it until the solvent is completely evaporated to obtain the membrane material; Step (4) Alkalization: Immerse the membrane material in an alkaline solution for ion exchange, and then wash it with deionized water to obtain an anion exchange membrane in the form of hydroxide ions.

2. The method for preparing a six-armed star-shaped branched polyarylpiperidine anion exchange membrane according to claim 1, characterized in that, In step (1): The molar ratio of p-terphenyl to N-methyl-4-piperidinone is 1:1.1-1.3; The molar ratio of tris(4-carbazole-9-ylphenyl)amine to p-terphenyl is from 0.01:1 to 0.03:1; The molar ratio of trifluoroacetic acid to p-terphenyl is 1-4:1; The molar ratio of trifluoromethanesulfonic acid to p-terphenyl is 4-10:

1.

3. The method for preparing a six-armed star-shaped branched polyarylpiperidine anion exchange membrane according to claim 1, characterized in that, In step (1): Solvent A is selected from methanol, ethanol, and alkaline solution; The organic solvent A is selected from one of dichloromethane, chloroform, and tetrahydrofuran; The vacuum drying temperature is 50-80 ℃, and the time is 24-48 h.

4. The method for preparing a six-armed star-shaped branched polyarylpiperidine anion exchange membrane according to claim 1, characterized in that, In step (2): For every 20 ml of organic solvent B, add 1-1.2 g of six-armed star-shaped branched polymer, 1.2-1.4 g of potassium carbonate, and 0.6-0.7 ml of iodomethane.

5. The method for preparing a six-armed star-shaped branched polyarylpiperidine anion exchange membrane according to claim 1, characterized in that, In step (2): The organic solvent B is dimethyl sulfoxide, N-methylpyrrolidone, or N,N-dimethylformamide; Solvent B is one of ethyl acetate, diethyl ether, or tetrahydrofuran; The vacuum drying temperature is 50-80 ℃, and the time is 24-48 h.

6. The method for preparing a six-armed star-shaped branched polyarylpiperidine anion exchange membrane according to claim 1, characterized in that, In step (3): The casting solution has a mass concentration of 3-8 wt%; The addition ratio of the quaternized polymer to organic solvent B is 0.6-1.6 g: 20 mL; The drying temperature is 40-70℃, and the drying time is 24-48 hours.

7. The method for preparing a six-armed star-shaped branched polyarylpiperidine anion exchange membrane according to claim 1, characterized in that, In step (4): at room temperature, the membrane material is immersed in a 1-2 M sodium hydroxide or potassium hydroxide solution for 24-48 hours.

8. A six-armed star-shaped branched carbazole-based anion exchange membrane, characterized in that, The six-armed star-shaped branched carbazole-based anion exchange membrane is prepared using the preparation method described in any one of claims 1-7. The membrane has an ether-free arylpiperidine as the main chain, iodomethane as the quaternizing agent, and tris(4-carbazole-9-ylphenyl)amine as the branching functional unit. Six ether-free arylpiperidine branches are connected by tris(4-carbazole-9-ylphenyl)amine to construct a star-shaped topology, inducing microphase separation. The introduced six-armed branched structure increases the free volume of the polymer. The polymer structure is as follows: Where x is the molar percentage of tris(4-carbazole-9-ylphenyl)amine unit to aryl monomer, and the value of x ranges from 1% to 3%.

9. An application of the six-armed star-shaped branched carbazole-based anion exchange membrane according to claim 8, characterized in that, It can be used as an anion exchange membrane in fuel cells and water electrolysis.

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