A branched polyarylpiperidine anion exchange membrane and its preparation method and application

Abstract

The present invention discloses a branched polyarylpiperidine anion exchange membrane, its preparation method, and application, belonging to the field of fuel cell technology. In the preparation method of the present invention, the reaction monomer 1 contains a branched structure, and the branched structure is introduced during the polymer preparation process to obtain a branched polyarylpiperidine anion exchange membrane. The anion exchange membrane prepared by the present invention has high conductivity, low water absorption and swelling properties, and excellent fuel cell performance. It can be used to prepare alkaline fuel cell materials or alkaline water electrolysis materials, and can also be used in fields such as electrodialysis, organic electrosynthesis, and carbon dioxide catalytic reduction.

Description

Technical Field

[0001] The present invention belongs to the technical field of fuel cells, and in particular relates to a branched polyarylpiperidine anion exchange membrane and a preparation method and application thereof. Background Art

[0002] Hydrogen energy has attracted widespread attention as an alternative energy source to replace fossil fuels and meet the requirements of global climate change. The global consensus is that the development of green hydrogen energy is crucial to optimizing the current energy structure and achieving sustainable human growth. The effective use of hydrogen energy is the main driving force of the hydrogen economy. As the twin stars of hydrogen energy, hydrogen fuel cells and water electrolysis hydrogen production technologies are of great significance. Anion exchange membranes are key materials for alkaline hydrogen fuel cells and alkaline water electrolysis, which play the role of isolating fuel and conducting OH. - It should have the dual function of high electrical conductivity and excellent chemical and mechanical stability.

[0003] Currently, achieving high mechanical stability in anion exchange membranes often comes at the expense of conductivity and chemical stability, often resulting in unsatisfactory overall performance. Branched polymers have excellent swelling properties, so developing branched anion exchange membranes that combine high conductivity, chemical stability, and excellent mechanical stability is a major challenge. Summary of the Invention

[0004] In response to the above-mentioned prior art, the present invention discloses a branched polyarylpiperidine anion exchange membrane and its preparation method and application, in order to solve the technical problems of the anion exchange membrane in the prior art, such as poor conductivity, poor chemical stability and high preparation cost.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is: to provide a branched polyarylpiperidine anion exchange membrane, which is polymerized by reaction precursor 1, reaction precursor 2 and N-methyl-4-piperidone; reaction precursor 1 is one of the compounds represented by formula (I),

[0006]

[0007] Reaction precursor 2 is one of the compounds represented by formula (II),

[0008]

[0009] The present invention also discloses a method for preparing the branched polyarylpiperidine anion exchange membrane, comprising the following steps:

[0010] S1: Reaction precursor 1, reaction precursor 2, and N-methyl-4-piperidone are dissolved in a solvent and stirred uniformly. Trifluoroacetic acid and trifluoromethanesulfonic acid are added to the resulting solution at -5 to 5°C, and the mixture is kept warm for reaction. The reaction solution is then precipitated in an alkaline solution to obtain a polymer solid.

[0011] S2: washing and drying the polymer solid, dissolving the polymer solid with a polar solvent at 40-80° C. to obtain a polymer solution with a concentration of 3-20 wt %, adding an alkaline substance to the polymer solution, reacting at 70-100° C. for 12-48 hours, then adding iodomethane, and reacting at room temperature for 12-48 hours to obtain a branched polyarylpiperidine polyelectrolyte resin solution;

[0012] S3: adding the branched polyarylpiperidine polyelectrolyte resin solution dropwise into a solvent for precipitation, followed by filtering, washing and drying to obtain a branched polyarylpiperidine polyelectrolyte resin;

[0013] S4: dissolving the branched polyarylpiperidine polyelectrolyte resin in a polar solvent to obtain a polyelectrolyte resin solution with a concentration of 3 to 30 wt%, casting the polyelectrolyte resin solution on a glass plate, drying it, and then soaking it in an alkaline solution, washing it, and drying it to obtain the product.

[0014] Based on the above technical solution, the present invention can also make the following improvements:

[0015] Furthermore, in step S1, the usage ratio of reaction precursor 1, reaction precursor 2, N-methyl-4-piperidone, solvent, trifluoroacetic acid and trifluoromethanesulfonic acid is 2-50 mmol: 50-98 mmol: 100-130 mmol: 5-20 ml: 1-5 ml: 5-10 ml; and the solvent in step S1 is dichloromethane.

[0016] Furthermore, the reaction time in step S1 is 5 to 24 hours; the alkaline solution is an aqueous solution of KOH, NaOH, Ca(OH)2 or ammonia.

[0017] Furthermore, in step S2, the drying temperature is 55-65° C., and the drying time is 8-10 hours; and the polar solvent is tetrahydrofuran, acetonitrile, N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide or dimethyl sulfoxide.

[0018] Furthermore, in step S2, the alkaline substance is KOH, NaOH, NH3·H2O or Ca(OH)2; and the mass ratio of the polymer solid, the alkaline substance and iodomethane is 1:0.5-5:1-5.

[0019] Furthermore, the solvent in step S3 is ethyl acetate; the drying temperature in step S3 is 55-65° C., and the drying time is 8-10 hours.

[0020] Furthermore, the drying temperature is 50-80° C., and the drying time is 8-24 hours; the alkaline solution in step S4 is a KOH aqueous solution with a concentration of 1 wt%; the soaking temperature is 55-65° C., and the soaking time is 12-48 hours.

[0021] Furthermore, in step S4, the drying temperature is 45-55° C., and the drying time is 8-10 hours.

[0022] The invention also discloses the use of the branched polyarylpiperidine anion exchange membrane in the preparation of alkaline fuel cell materials or alkaline water electrolysis materials.

[0023] The beneficial effects of the present invention are:

[0024] 1. The branched polyarylpiperidine anion exchange membrane prepared by the present invention has high electrical conductivity and low water absorption and swelling rate.

[0025] 2. The branched polyarylpiperidine anion exchange membrane prepared by the present invention has excellent alkali resistance and stability. When the membrane is immersed in a KOH solution at 80° C. for 3000 hours, the conductivity loss is only 10.6%.

[0026] 3. The branched polyarylpiperidinium ion exchange membrane prepared by the present invention has excellent fuel cell performance, with a peak power density of up to 1.41 W / cm 2 . BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The conductivity of the anion exchange membrane prepared in Example 1 changes with time;

[0028] Figure 2 This is the polarization curve of the anion exchange membrane fuel cell prepared in Example 1. DETAILED DESCRIPTION

[0029] The specific implementation methods of the present invention are described in detail below with reference to the embodiments.

[0030] Example 1

[0031] A method for preparing a branched polyarylpiperidine anion exchange membrane, the method comprising the following steps:

[0032] S1: Add 2 mmol of reaction precursor 1, 50 mmol of reaction precursor 2, and 100 mmol of N-methyl-4-piperidone to a 50 mL round-bottom flask. The structures of reaction precursor 1 and reaction precursor 2 are shown below:

[0033] Reaction precursor 1:

[0034] Reaction Precursor 2:

[0035] The round-bottom flask was fixed on a magnetic stirrer, and 10 mL of dichloromethane was added and stirred to dissolve the reaction precursor. The round-bottom flask was then placed in a basin of ice water. The temperature of the solution in the round-bottom flask was monitored with a thermometer. 1 mL of trifluoroacetic acid and 5 mL of trifluoromethanesulfonic acid were added dropwise to the solution at 0°C. The mixture was then kept warm for 5 hours. The reaction solution was then added to an aqueous sodium hydroxide solution and precipitated and filtered to obtain a polymer solid.

[0036] S2: washing the polymer solid with pure water until its pH is neutral, and then drying it at 60° C. for 8 hours; adding 1 g of the dried polymer solid and tetrahydrofuran to another round-bottom flask, stirring and dissolving them at 40° C. to obtain a polymer solution with a concentration of 3 wt%. When the polymer solution is cooled to room temperature, adding 1 g of sodium hydroxide to the polymer solution, and then stirring and reacting at 70° C. for 12 hours. After the reaction solution is cooled to room temperature, adding 2 g of iodomethane, and stirring and reacting at room temperature for 12 hours to obtain a branched polyarylpiperidine polyelectrolyte resin solution;

[0037] S3: adding the branched polyarylpiperidine polyelectrolyte resin solution prepared in step S2 dropwise to ethyl acetate for precipitation, filtering and washing the solid with pure water until the pH thereof is neutral, and then drying the solid at 60° C. for 10 h to obtain a branched polyarylpiperidine polyelectrolyte resin;

[0038] S4: Take 1 g of the branched polyarylpiperidine polyelectrolyte resin obtained in step S3 and dissolve it in N,N-dimethylformamide to obtain a polyelectrolyte resin solution with a concentration of 3 wt%, and cast the polyelectrolyte resin solution on a glass plate, dry it at 50°C for 24 hours to form a film, then place the dried film in a potassium hydroxide aqueous solution with a concentration of 1 mol / L and soak it at 60°C for 12 hours. After taking it out, wash the residual potassium hydroxide with pure water, and then place the film in a vacuum drying oven for drying at a drying temperature of 50°C, a vacuum degree of -0.1 MPa, and a drying time of 10 hours. After drying, a branched polyarylpiperidine anion exchange membrane is obtained.

[0039] Example 2

[0040] A method for preparing a branched polyarylpiperidine anion exchange membrane, the method comprising the following steps:

[0041] S1: Add 10 mmol of reaction precursor 1, 98 mmol of reaction precursor 2, and 130 mmol of N-methyl-4-piperidone to a 50 mL round-bottom flask. The structures of reaction precursor 1 and reaction precursor 2 are shown below:

[0042] Reaction precursor 1:

[0043] Reaction Precursor 2:

[0044] The round-bottom flask was fixed on a magnetic stirrer, and 20 mL of dichloromethane was added and stirred to dissolve the reaction precursor. The round-bottom flask was then placed in a basin of ice water. The temperature of the solution in the round-bottom flask was monitored with a thermometer. 2 mL of trifluoroacetic acid and 7 mL of trifluoromethanesulfonic acid were added dropwise to the solution at 0°C. The mixture was then kept warm for 10 hours. The reaction solution was then added to a potassium hydroxide aqueous solution and precipitated and filtered to obtain a polymer solid.

[0045] S2: washing the polymer solid with pure water until its pH is neutral, and then drying it at 60° C. for 10 hours; adding 1 g of the dried polymer solid and N-methylpyrrolidone to another round-bottom flask, stirring and dissolving them at 60° C. to obtain a polymer solution with a concentration of 5 wt%. When the polymer solution is cooled to room temperature, adding 0.5 g of potassium hydroxide to the polymer solution, and then stirring and keeping the mixture at 100° C. for 48 hours. After the reaction solution is cooled to room temperature, adding 3 g of iodomethane, and stirring and reacting at room temperature for 24 hours to obtain a branched polyarylpiperidine polyelectrolyte resin solution;

[0046] S3: adding the branched polyarylpiperidine polyelectrolyte resin solution prepared in step S2 dropwise to ethyl acetate for precipitation, filtering and washing the solid with pure water until the pH thereof is neutral, and then drying the solid at 60° C. for 8 h to obtain a branched polyarylpiperidine polyelectrolyte resin;

[0047] S4: 1 g of the branched polyarylpiperidine polyelectrolyte resin obtained in step S3 is dissolved in N-methylpyrrolidone to obtain a polyelectrolyte resin solution with a concentration of 5 wt%, and the polyelectrolyte resin solution is cast on a glass plate and dried at 80° C. for 8 h to form a film. The dried film is then placed in a 1 mol / L potassium hydroxide aqueous solution and soaked at 60° C. for 24 h. After being taken out, the residual potassium hydroxide is washed with pure water, and the film is placed in a vacuum drying oven for drying at a drying temperature of 50° C., a vacuum degree of -0.1 MPa, and a drying time of 10 h. After drying, a branched polyarylpiperidine anion exchange membrane is obtained.

[0048] Example 3

[0049] A method for preparing a branched polyarylpiperidine anion exchange membrane, the method comprising the following steps:

[0050] S1: Add 20 mmol of reaction precursor 1, 80 mmol of reaction precursor 2, and 130 mmol of N-methyl-4-piperidone to a 50 mL round-bottom flask. The structures of reaction precursor 1 and reaction precursor 2 are shown below:

[0051] Reaction precursor 1:

[0052] Reaction Precursor 2:

[0053] The round-bottom flask was fixed on a magnetic stirrer device, and 10 mL of dichloromethane was added and stirred to dissolve the reaction precursor. The round-bottom flask was then placed in a basin of ice water. The temperature of the solution in the round-bottom flask was monitored with a thermometer. 3 mL of trifluoroacetic acid and 8 mL of trifluoromethanesulfonic acid were sequentially added dropwise to the solution at 3°C. The mixture was then kept warm for 24 hours. The reaction solution was then added to a calcium hydroxide aqueous solution, precipitated, and filtered to obtain a polymer solid.

[0054] S2: washing the polymer solid with pure water until its pH is neutral, and then drying it at 80° C. for 9 hours; adding 1 g of the dried polymer solid and dimethyl sulfoxide to another round-bottom flask, stirring and dissolving them at 80° C. to obtain a polymer solution with a concentration of 20 wt%. When the polymer solution is cooled to room temperature, adding 4 g of potassium hydroxide to the polymer solution, and then stirring and reacting at 90° C. for 48 hours. After the reaction solution is cooled to room temperature, adding 4 g of iodomethane, and stirring and reacting at room temperature for 48 hours to obtain a branched polyarylpiperidine polyelectrolyte resin solution;

[0055] S3: adding the branched polyarylpiperidine polyelectrolyte resin solution in step S2 dropwise to ethyl acetate for precipitation, filtering and washing the solid with pure water until the pH is neutral, and then drying the solid at 60° C. for 9 h to obtain a branched polyarylpiperidine polyelectrolyte resin;

[0056] S4: 1 g of the branched polyarylpiperidine polyelectrolyte resin obtained in step S3 is dissolved in dimethyl sulfoxide to obtain a polyelectrolyte resin solution with a concentration of 20 wt%, and the polyelectrolyte resin solution is cast on a glass plate and dried at 80° C. for 24 h to form a film. The dried film is then placed in a 1 mol / L potassium hydroxide aqueous solution and soaked at 60° C. for 48 h. After being taken out, the residual potassium hydroxide is washed with pure water, and the film is placed in a vacuum drying oven for drying at a drying temperature of 50° C., a vacuum degree of -0.1 MPa, and a drying time of 10 h. After drying, a branched polyarylpiperidine anion exchange membrane is obtained.

[0057] Example 4

[0058] A method for preparing a branched polyarylpiperidine anion exchange membrane, the method comprising the following steps:

[0059] S1: Add 2 mmol of reaction precursor 1, 50 mmol of reaction precursor 2, and 130 mmol of N-methyl-4-piperidone to a 50 mL round-bottom flask. The structures of reaction precursor 1 and reaction precursor 2 are shown below:

[0060] Reaction precursor 1:

[0061] Reaction Precursor 2:

[0062] The round-bottom flask was fixed on a magnetic stirrer, and 5 mL of dichloromethane was added and stirred to dissolve the reaction precursor. The round-bottom flask was then placed in a basin of ice water. The temperature of the solution in the round-bottom flask was monitored with a thermometer. 5 mL of trifluoroacetic acid and 5 mL of trifluoromethanesulfonic acid were added dropwise to the solution at 5°C. The mixture was kept warm for 5 hours and then added to an aqueous ammonia solution. The polymer solid was obtained after precipitation and filtration.

[0063] S2: washing the polymer solid with pure water until its pH is neutral, and then drying it at 40°C for 8 hours; adding 1 g of the dried polymer solid and N,N-dimethylacetamide to another round-bottom flask, stirring and dissolving them at 40°C to obtain a polymer solution with a concentration of 3 wt%. When the polymer solution is cooled to room temperature, adding 0.5 g of potassium hydroxide to the polymer solution, and then stirring and reacting at 70°C for 12 hours. After the reaction solution is cooled to room temperature, adding 1 g of iodomethane, stirring and reacting at room temperature for 12 hours, at which time a significant increase in the viscosity of the reaction solution is observed, thereby obtaining a branched polyarylpiperidine polyelectrolyte resin solution;

[0064] S3: adding the branched polyarylpiperidine polyelectrolyte resin solution prepared in step S2 dropwise to ethyl acetate for precipitation, filtering and washing the solid with pure water until the pH thereof is neutral, and then drying the solid at 55° C. for 9 h to obtain a branched polyarylpiperidine polyelectrolyte resin;

[0065] S4: 1 g of the branched polyarylpiperidine polyelectrolyte resin obtained in step S3 is dissolved in N-methylpyrrolidone to obtain a polyelectrolyte resin solution with a concentration of 3 wt%, and the polyelectrolyte resin solution is cast on a glass plate and dried at 50° C. for 8 h to form a film. The dried film is then placed in a 1 mol / L potassium hydroxide aqueous solution and soaked at 55° C. for 12 h. After being taken out, the residual potassium hydroxide is washed with pure water, and the film is placed in a vacuum drying oven for drying at a drying temperature of 45° C., a vacuum degree of -0.1 MPa, and a drying time of 8 h. After drying, a branched polyarylpiperidine anion exchange membrane is obtained.

[0066] Example 5

[0067] A method for preparing a branched polyarylpiperidine anion exchange membrane, the method comprising the following steps:

[0068] S1: Add 50 mmol of reaction precursor 1, 95 mmol of reaction precursor 2, and 100 mmol of N-methyl-4-piperidone to a 50 mL round-bottom flask. The structures of reaction precursor 1 and reaction precursor 2 are shown below:

[0069] Reaction precursor 1:

[0070] Reaction Precursor 2:

[0071] The round-bottom flask was fixed on a magnetic stirrer, and 10 mL of dichloromethane was added. The reaction precursor was dissolved by stirring. 5 mL of trifluoroacetic acid and 10 mL of trifluoromethanesulfonic acid were added dropwise to the solution at -5°C. The mixture was kept warm for 24 hours. The reaction solution was then added to an aqueous sodium hydroxide solution for precipitation and filtration to obtain a polymer solid.

[0072] S2: washing the polymer solid with pure water until its pH is neutral, and then drying it at 80°C for 8 hours; adding 1 g of the dried polymer solid and acetonitrile to another round-bottom flask, stirring and dissolving them at 60°C to obtain a polymer solution with a concentration of 20 wt%. When the polymer solution is cooled to room temperature, adding 5 g of sodium hydroxide to the polymer solution, and then stirring and incubating at 100°C for 48 hours. After the reaction solution is cooled to room temperature, adding 5 g of iodomethane, and stirring and reacting at room temperature for 48 hours, at which time a significant increase in the viscosity of the reaction solution is observed, thereby obtaining a branched polyarylpiperidine polyelectrolyte resin solution;

[0073] S3: adding the branched polyarylpiperidine polyelectrolyte resin solution prepared in step S2 dropwise to ethyl acetate for precipitation, filtering and washing the solid with pure water until the pH thereof is neutral, and then drying the solid at 65° C. for 10 h to obtain a branched polyarylpiperidine polyelectrolyte resin;

[0074] S4: 1 g of the branched polyarylpiperidine polyelectrolyte resin obtained in step S3 is dissolved in N,N-dimethylacetamide to obtain a polyelectrolyte resin solution with a concentration of 30 wt%, and the polyelectrolyte resin solution is cast on a glass plate and dried at 80°C for 24 hours to form a film. The dried film is then placed in a 1 mol / L potassium hydroxide aqueous solution and soaked at 65°C for 48 hours. After being taken out, the residual potassium hydroxide is washed with pure water, and the film is placed in a vacuum drying oven for drying at a drying temperature of 55°C, a vacuum degree of -0.1 MPa, and a drying time of 9 hours. After drying, a branched polyarylpiperidine anion exchange membrane is obtained.

[0075] Example 6

[0076] A method for preparing a branched polyarylpiperidine anion exchange membrane, the method comprising the following steps:

[0077] S1: Add 5 mmol of reaction precursor 1, 60 mmol of reaction precursor 2, and 110 mmol of N-methyl-4-piperidone to a 50 mL round-bottom flask. The structures of reaction precursor 1 and reaction precursor 2 are shown below:

[0078] Reaction precursor 1:

[0079] Reaction Precursor 2:

[0080] The round-bottom flask was fixed on a magnetic stirrer, and 7 mL of dichloromethane was added. The reaction precursor was dissolved by stirring. 1 mL of trifluoroacetic acid and 7 mL of trifluoromethanesulfonic acid were added dropwise to the solution at -3°C. The mixture was kept warm for 7 h. The reaction solution was then added to an aqueous ammonia solution. The polymer solid was obtained after precipitation and filtration.

[0081] S2: The polymer solid was washed with pure water until its pH was neutral, and then dried at 60° C. for 8 h. 1 g of the dried polymer solid and tetrahydrofuran were added to another round-bottom flask, and the mixture was stirred and dissolved at 60° C. to obtain a polymer solution with a concentration of 7 wt%. When the polymer solution was cooled to room temperature, 2 g of aqueous ammonia was added to the polymer solution, and then the mixture was stirred and kept at 80° C. for 17 h. After the reaction solution was cooled to room temperature, 1 g of methyl iodide was added, and the mixture was stirred and reacted at room temperature for 18 h. At this time, a significant increase in the viscosity of the reaction solution was observed, thereby obtaining a branched polyarylpiperidine polyelectrolyte resin solution.

[0082] S3: adding the branched polyarylpiperidine polyelectrolyte resin solution prepared in step S2 dropwise to ethyl acetate for precipitation, filtering and washing the solid with pure water until the pH thereof is neutral, and then drying the solid at 58° C. for 9 h to obtain a branched polyarylpiperidine polyelectrolyte resin;

[0083] S4: 1 g of the branched polyarylpiperidine polyelectrolyte resin obtained in step S3 is dissolved in acetonitrile to obtain a polyelectrolyte resin solution with a concentration of 5 wt%, and the polyelectrolyte resin solution is cast on a glass plate and dried at 55° C. for 10 h to form a film. The dried film is then placed in a 1 mol / L potassium hydroxide aqueous solution and soaked at 58° C. for 16 h. After being taken out, the residual potassium hydroxide is washed with pure water, and the film is placed in a vacuum drying oven for drying at a drying temperature of 48° C., a vacuum degree of -0.1 MPa, and a drying time of 10 h. After drying, a branched polyarylpiperidine anion exchange membrane is obtained.

[0084] Example 7

[0085] A method for preparing a branched polyarylpiperidine anion exchange membrane, the method comprising the following steps:

[0086] S1: Add 30 mmol of reaction precursor 1, 70 mmol of reaction precursor 2, and 120 mmol of N-methyl-4-piperidone to a 50 mL round-bottom flask. The structures of reaction precursor 1 and reaction precursor 2 are shown below:

[0087] Reaction precursor 1:

[0088] Reaction Precursor 2:

[0089] The round-bottom flask was fixed on a magnetic stirrer device, and 10 mL of dichloromethane was added and stirred to dissolve the reaction precursor. The round-bottom flask was then placed in a basin of ice water. The temperature of the solution in the round-bottom flask was monitored with a thermometer. 3 mL of trifluoroacetic acid and 10 mL of trifluoromethanesulfonic acid were added dropwise to the solution at 0°C, and the reaction was kept warm for 12 hours. The reaction solution was then added to a potassium hydroxide aqueous solution, precipitated, and filtered to obtain a polymer solid.

[0090] S2: washing the polymer solid with pure water until its pH is neutral, and then drying it at 75°C for 8 hours; adding 1 g of the dried polymer solid and N,N-dimethylformamide to another round-bottom flask, stirring and dissolving to obtain a polymer solution with a concentration of 10 wt%. When the polymer solution is cooled to room temperature, adding 3 g of calcium hydroxide to the polymer solution, and then stirring and insulating the solution at 90°C for 36 hours. After the reaction solution is cooled to room temperature, adding 4 g of iodomethane, stirring and reacting at room temperature for 36 hours, at which time a significant increase in the viscosity of the reaction solution is observed, thereby obtaining a branched polyarylpiperidine polyelectrolyte resin solution;

[0091] S3: adding the branched polyarylpiperidine polyelectrolyte resin solution prepared in step S2 dropwise to ethyl acetate for precipitation, filtering and washing the solid with pure water until the pH thereof is neutral, and then drying the solid at 63° C. for 9 h to obtain a branched polyarylpiperidine polyelectrolyte resin;

[0092] S4: 1 g of the branched polyarylpiperidine polyelectrolyte resin obtained in step S3 is dissolved in tetrahydrofuran to obtain a polyelectrolyte resin solution with a concentration of 25 wt%, and the polyelectrolyte resin solution is cast on a glass plate and dried at 70° C. for 20 h to form a film. The dried film is then placed in a 1 mol / L potassium hydroxide aqueous solution and soaked at 62° C. for 36 h. After being taken out, the residual potassium hydroxide is washed with pure water, and the film is placed in a vacuum drying oven for drying at a drying temperature of 54° C., a vacuum degree of -0.1 MPa, and a drying time of 10 h. After drying, a branched polyarylpiperidine anion exchange membrane is obtained.

[0093] Comparative Example 1

[0094] A method for preparing a polyarylpiperidine anion exchange membrane, the method comprising the following steps:

[0095] S1: Add 2 mmol of reaction precursor 1, 50 mmol of reaction precursor 2, and 100 mmol of N-methyl-4-piperidone to a 50 mL round-bottom flask. The structures of reaction precursor 1 and reaction precursor 2 are shown below:

[0096] Reaction precursor 1:

[0097] Reaction Precursor 2:

[0098] The round-bottom flask was fixed on a magnetic stirrer, and 10 mL of dichloromethane was added and stirred to dissolve the reaction precursor. The round-bottom flask was then placed in a basin of ice water. The temperature of the solution in the round-bottom flask was monitored with a thermometer. 1 mL of trifluoroacetic acid and 5 mL of trifluoromethanesulfonic acid were added dropwise to the solution at 0°C. The mixture was then kept warm for 5 hours. The reaction solution was then added to an aqueous sodium hydroxide solution and precipitated and filtered to obtain a polymer solid.

[0099] S2: washing the polymer solid with pure water until its pH is neutral, and then drying it at 60°C for 8 hours; adding 1 g of the dried polymer solid and tetrahydrofuran to another round-bottom flask, stirring and dissolving them at 40°C to obtain a polymer solution with a concentration of 3 wt%. When the polymer solution is cooled to room temperature, adding 1 g of sodium hydroxide to the polymer solution, and then stirring and reacting at 70°C for 12 hours. After the reaction solution is cooled to room temperature, adding 2 g of iodomethane, and stirring and reacting at room temperature for 12 hours to obtain a polyarylpiperidine polyelectrolyte resin solution;

[0100] S3: adding the polyarylpiperidine polyelectrolyte resin solution in step S2 dropwise to ethyl acetate for precipitation, filtering and washing the solid with pure water until the pH is neutral, and then drying the solid at 60° C. for 10 h to obtain a polyarylpiperidine polyelectrolyte resin;

[0101] S4: 1 g of the polyarylpiperidine polyelectrolyte resin obtained in step S3 is dissolved in N,N-dimethylformamide to obtain a polyelectrolyte resin solution with a concentration of 3 wt%, and the polyelectrolyte resin solution is cast on a glass plate and dried at 50° C. for 24 h to form a film. The dried film is then placed in a 1 mol / L potassium hydroxide aqueous solution and soaked at 60° C. for 12 h. After being taken out, the residual potassium hydroxide is washed with pure water, and the film is placed in a vacuum drying oven for drying at a drying temperature of 50° C., a vacuum degree of -0.1 MPa, and a drying time of 10 h. After drying, a polyarylpiperidine anion exchange membrane is obtained.

[0102] Test example

[0103] The branched polyarylpiperidine anion exchange membranes prepared in the examples of the present invention have similar performances. Examples 1 to 7 are used as examples to illustrate the performances of related products.

[0104] 1. Conductivity test

[0105] The anion exchange membranes prepared in Examples 1 to 7 and Comparative Example 1 were cut into rectangular membrane strips of 4 cm × 1 cm. The samples were immersed in a solution of 1 mol L -1 The sample was then placed in a NaOH aqueous solution for 48 h, and the solution was replaced twice during this period to convert the sample into OH - The sample was quickly clamped in the test fixture, immersed in ultrapure water, and tested using an AC impedance meter (Solartron 1287 & 1260) with a test frequency range of 1 to 10 6 The conductivity was then calculated based on the Nyquist plot of the test results. The results are shown in Table 1. It can be seen from the table that the conductivity of the branched polyarylpiperidine anion exchange membrane in the embodiment is significantly greater than that in the comparative example.

[0106] Table 1

[0107]

[0108]

[0109] 2. Water absorption and swelling test

[0110] The anion exchange membranes prepared in Examples 1 to 4 and Comparative Example 1 were subjected to water absorption and swelling tests, and the dry membranes and the changes in mass and length of the wet membranes at different temperatures were tested for characterization. The results are shown in Table 2. It can be seen from the table that the water absorption and swelling ratio of the anion exchange membranes in the examples are significantly smaller than those in the comparative example.

[0111] Table 2

[0112]

[0113]

[0114] 3. Alkali resistance stability test

[0115] The anion exchange membrane prepared in Example 1 was immersed in a 1 mol / L KOH solution at 80°C, and the conductivity change of the anion exchange membrane at different times was tested. Figure 1As shown in the figure, it can be seen that the conductivity loss of the branched polyarylpiperidine anion exchange membrane in the embodiment is only 10.6% after immersion for 3000 hours, indicating that the branched polyarylpiperidine anion exchange membrane in the present invention has excellent alkali resistance and stability.

[0116] 4. Battery performance test

[0117] First, an appropriate amount of commercially available Pt / C and PtRu / C catalysts with a concentration of 60 wt% and isopropanol were weighed and added to a sample tube, and then 20 μL of a 5 wt% branched polyarylpiperidine polyelectrolyte resin solution prepared from the branched polyarylpiperidine polyelectrolyte resin in Example 1 was added, and the solvent was DMSO. The sample tube was ultrasonicated in a water bath for 1 h to form a catalyst ink. The ultrasonically prepared 60 wt% Pt / C and PtRu / C catalyst inks were sprayed on both sides of the branched polyarylpiperidine anion exchange membrane prepared in Example 1 to form a cathode catalyst layer and an anode catalyst layer, thereby preparing a fuel cell chip (catalyst-coated membrane, CCM) with a loading of 0.4 mg / cm 2 Finally, the prepared CCM was assembled in a fuel cell test system (850eMulti Range, Scribner Associates Co) for battery performance testing.

[0118] The test conditions are: battery temperature 80℃, pure hydrogen as fuel, pure oxygen as oxidant, the results are as follows Figure 2 As shown in the figure, it can be seen that the branched polyarylpiperidine anion exchange membrane in Example 1 exhibits excellent battery performance, with a peak power density of up to 1.41 W / cm 2 .

[0119] Although the specific embodiments of the present invention have been described in detail in conjunction with the embodiments, this should not be construed as limiting the scope of protection of this patent. Within the scope described by the claims, various modifications and variations that can be made by those skilled in the art without creative work still fall within the scope of protection of this patent.

Claims

1. A branched polyarylpiperidine anion exchange membrane, characterized in that The branched polyarylpiperidine anion exchange membrane is polymerized by reaction precursor 1, reaction precursor 2 and N-methyl-4-piperidone; the reaction precursor 1 is one of the compounds represented by formula (I), The reaction precursor 2 is one of the compounds represented by formula (II), 2. The method for preparing the branched polyarylpiperidine anion exchange membrane according to claim 1, wherein The following steps are involved: S1: Dissolving the reaction precursor 1, the reaction precursor 2, and N-methyl-4-piperidone in a solvent, stirring uniformly, and adding trifluoroacetic acid and trifluoromethanesulfonic acid to the resulting solution at -5 to 5°C, keeping the temperature to react, and then precipitating the reaction solution in an alkaline solution to obtain a polymer solid; S2: washing and drying the polymer solid, dissolving the polymer solid with a polar solvent at 40-80° C. to obtain a polymer solution with a concentration of 3-20 wt %, adding an alkaline substance to the polymer solution, reacting at 70-100° C. for 12-48 hours, then adding iodomethane, and reacting at room temperature for 12-48 hours to obtain a branched polyarylpiperidine polyelectrolyte resin solution; S3: adding the branched polyarylpiperidine polyelectrolyte resin solution dropwise into a solvent for precipitation, and then filtering, washing and drying to obtain a branched polyarylpiperidine polyelectrolyte resin; S4: dissolving the branched polyarylpiperidine polyelectrolyte resin in a polar solvent to obtain a polyelectrolyte resin solution with a concentration of 3 to 30 wt%, casting the polyelectrolyte resin solution on a glass plate, drying it, and then soaking it in an alkaline solution, washing it, and drying it to obtain the product.

3. The method for preparing a branched polyarylpiperidine anion exchange membrane according to claim 2, wherein: In step S1, the ratio of reaction precursor 1, reaction precursor 2, N-methyl-4-piperidone, solvent, trifluoroacetic acid and trifluoromethanesulfonic acid is 2-50 mmol: 50-98 mmol: 100-130 mmol: 5-20 ml: 1-5 ml: 5-10 ml; the solvent in step S1 is dichloromethane.

4. The method for preparing a branched polyarylpiperidine anion exchange membrane according to claim 2, wherein: The reaction time in step S1 is 5 to 24 hours; the alkaline solution is an aqueous solution of KOH, NaOH, Ca(OH)2 or ammonia.

5. The method for preparing a branched polyarylpiperidine anion exchange membrane according to claim 2, wherein: In step S2, the drying temperature is 55-65° C., and the drying time is 8-10 hours; the polar solvent is tetrahydrofuran, acetonitrile, N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide or dimethyl sulfoxide.

6. The method for preparing a branched polyarylpiperidine anion exchange membrane according to claim 2, wherein: In step S2, the alkaline substance is KOH, NaOH, NH3·H2O or Ca(OH)2; and the mass ratio of the polymer solid, the alkaline substance and iodomethane is 1:0.5-5:1-5.

7. The method for preparing a branched polyarylpiperidine anion exchange membrane according to claim 2, wherein: The solvent in step S3 is ethyl acetate; the drying temperature in step S3 is 55-65° C., and the drying time is 8-10 hours.

8. The method for preparing a branched polyarylpiperidine anion exchange membrane according to claim 2, wherein: The drying temperature is 50-80° C., and the drying time is 8-24 hours. The alkaline solution in step S4 is a KOH aqueous solution with a concentration of 1 wt %. The soaking temperature is 55-65° C., and the soaking time is 12-48 hours.

9. The method for preparing a branched polyarylpiperidine anion exchange membrane according to claim 2, wherein: In step S4, the drying temperature is 45-55° C., and the drying time is 8-10 hours.

10. Use of the branched polyarylpiperidine anion exchange membrane according to claim 1 in the preparation of alkaline fuel cell materials or alkaline water electrolysis materials.

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