A bi-piperidinium cation anion exchange membrane and its preparation method and application

Abstract

The present invention discloses a bi-piperidinium cation anion exchange membrane, its preparation method, and application, belonging to the technical field of polymer materials. The present invention first synthesizes a polymer containing a piperidinium cation in the main chain, wherein the main chain structure contains a non-rotatable aromatic hydrocarbon with a bromoalkyl side chain. Bromine atoms are then used as reaction sites to react with a piperidinium cation precursor to form a grafted piperidinium cation. The prepared bi-piperidinium cation anion exchange membrane has a bi-piperidinium cation structure and side chain structure that help improve the membrane's conductivity and chemical stability. Furthermore, the membrane has good mechanical properties, low water absorption and swelling properties, and excellent fuel cell performance. The membrane 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, or carbon dioxide catalytic reduction.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials, and particularly relates to a bi-piperidinium cation anion exchange membrane and a preparation method and application thereof. Background Art

[0002] In response to the urgent need for global energy transition and climate change, hydrogen energy, as a clean and efficient alternative energy source, is increasingly becoming a research hotspot in the international energy sector. Hydrogen energy is not only seen as a key path to reducing dependence on fossil fuels and lowering greenhouse gas emissions, but also carries the important mission of driving the transformation of the global energy structure toward a low-carbon, sustainable one. The rise of the hydrogen economy relies on the simultaneous development and breakthroughs of upstream and downstream technologies in the hydrogen energy industry chain. Performance optimization and technological innovation in hydrogen fuel cells and water electrolysis, the two core links in hydrogen energy utilization and production, are particularly crucial.

[0003] Anion exchange membranes are core components in alkaline hydrogen fuel cells and alkaline water electrolysis systems. Their performance directly affects the energy conversion efficiency and long-term operational stability of the entire system. Ideal anion exchange membranes should combine high ionic conductivity, excellent chemical stability (to resist degradation in strong alkaline environments), and outstanding mechanical stability to ensure high efficiency and long life operation of the equipment. However, a major challenge facing current technology is that improving one performance often comes at the expense of other properties. In particular, it is difficult to simultaneously optimize both conductivity and chemical stability while pursuing high mechanical stability. This has severely restricted the widespread promotion and performance improvement of anion exchange membranes in practical applications.

[0004] Therefore, developing an innovative anion exchange membrane material that has high electrical conductivity and chemical stability while also having excellent mechanical strength has become the key to pushing hydrogen energy technology to new heights and accelerating the arrival of the hydrogen economy era. Summary of the Invention

[0005] In response to the above-mentioned prior art, the present invention discloses a bi-type piperidinium cation anion exchange membrane and its preparation method and application, in order to solve the technical problems of the prior art anion exchange membrane such as poor conductivity, poor chemical stability, and poor mechanical stability.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is: to provide a method for preparing a bi-piperidinium cationic anion exchange membrane, which comprises the following steps:

[0007] 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 a neutral solution, washed and dried to obtain a polymer solid. Reaction precursor 1 is one of the compounds represented by formula (I), wherein n is an integer from 1 to 15.

[0008]

[0009] Reaction precursor 2 is one of the compounds represented by formula (II),

[0010]

[0011] S2: dissolving the polymer solid in a polar solvent to obtain a polymer solution having a concentration of 3 to 20 wt%, adding methyl iodide and an alkaline substance to the polymer solution, reacting at 20 to 50° C. for 12 to 48 hours, adding the reaction solution dropwise to the solvent for precipitation, and then filtering, washing, and drying to obtain a main-chain piperidinium cationic polyelectrolyte resin;

[0012] S3: dissolving a main-chain piperidinium cationic polyelectrolyte resin in a polar solvent to obtain a polyelectrolyte resin solution having a concentration of 3 to 20 wt%, adding N-methylpiperidine to the polyelectrolyte resin solution, reacting at 20 to 50° C. for 12 to 48 hours, adding the reaction solution dropwise to the solvent for precipitation, and then filtering, washing, and drying to obtain a bi-piperidinium cationic anion exchange resin;

[0013] S4: dissolving a bis-piperidinium cationic anion exchange resin in a polar solvent to obtain a bis-piperidinium cationic anion exchange resin solution having a concentration of 3 to 30 wt%, casting the bis-piperidinium cationic anion exchange 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] On the basis of the above technical solution, the present invention can also be improved as follows.

[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: 50-95 mmol: 100-130 mmol: 5-10 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 neutral solution is at least one of NaCl, KCl and Na2SO4 aqueous solutions; and the drying temperature in steps S1, S2 and S3 is 55 to 65°C.

[0017] Furthermore, in step S2, the alkaline substance is at least one of KOH, NaOH, NH3·H2O and Ca(OH)2, and the mass ratio of the polymer solid, the alkaline substance and iodomethane is 1:0.5~5:1~5; in steps S2, S3 and S4, the polar solvent is at least one of tetrahydrofuran, acetonitrile, N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide and dimethyl sulfoxide.

[0018] Furthermore, the solvent in steps S2 and S3 is ethyl acetate.

[0019] Furthermore, in step S3, the mass ratio of N-methylpiperidine to the main chain piperidinium cationic polyelectrolyte resin is 1 to 5:1.

[0020] Furthermore, in step S4, the drying temperature is 50-80° C., and the drying time is 8-24 hours; the alkaline solution 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, the drying temperature in step S4 is 45-55°C.

[0022] The invention also discloses the use of the bi-piperidinium cation anion exchange membrane in the preparation of alkaline fuel cell materials, carbon dioxide reduction electrolyte materials or alkaline water electrolysis materials.

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

[0024] 1. The present invention introduces a non-rotatable aromatic hydrocarbon containing a bromoalkyl side chain into the main chain piperidinium cation polymer structure. The rigid structure of the non-rotatable aromatic hydrocarbon helps maintain the stability of the polymer structure. The bromine atoms in the bromoalkyl side chain of the non-rotatable aromatic hydrocarbon then react with a piperidinium cation precursor containing a reactive group to form a grafted piperidinium cation. The presence of the side chain can increase the distance between polymer chains, forming a more spacious ion channel, thereby improving conductivity. The piperidinium cation has a stable cyclic structure, and the bi-piperidinium cation structure can improve the conductivity of the membrane and enhance its chemical stability.

[0025] 2. The bi-type piperidinium cation anion exchange membrane prepared by the present invention has high conductivity, low water absorption and swelling rate, and good mechanical strength.

[0026] 3. The bi-piperidinium cationic 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, the degradation rate of the cationic group can be as low as 7.6% after 1000 hours.

[0027] 4. The bi-piperidinium cation anion exchange membrane prepared by the present invention has excellent fuel cell performance, with a peak power density of up to 1.38W / cm 2.

[0028] 5. The preparation method of the present invention is simple and efficient. The prepared bi-piperidinium cation anion exchange membrane can be used to prepare alkaline fuel cell materials or alkaline water electrolysis materials, and can also be applied to the fields of electrodialysis, organic electrosynthesis or carbon dioxide catalytic reduction technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The conductivity of the samples in Examples 1 to 3 and Comparative Example 1 varies with temperature;

[0030] Figure 2 Graph showing the tensile strength of the samples in Examples 1 to 3 and Comparative Example 1;

[0031] Figure 3 The figure is a graph showing the alkali resistance stability test results of the samples in Examples 1 to 3 and Comparative Example 1;

[0032] Figure 4 The graphs are as follows: the water absorption rate of the samples in Examples 1 to 3 and Comparative Example 1 varies with temperature;

[0033] Figure 5 The swelling ratio of the samples in Examples 1 to 3 and Comparative Example 1 varies with temperature;

[0034] Figure 6 This is the polarization curve of the sample fuel cell in Example 1. DETAILED DESCRIPTION

[0035] The specific implementation methods of the present invention are described in detail below with reference to the embodiments.

[0036] Example 1

[0037] A method for preparing a bi-piperidinium cation anion exchange membrane, the method comprising the following steps:

[0038] S1: Add 5 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:

[0039] Reaction precursor 1

[0040] Reaction Precursor 2

[0041] The round-bottom flask was fixed on a magnetic stirrer device, 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. 1 mL of trifluoroacetic acid and 5 mL of trifluoromethanesulfonic acid were sequentially added dropwise to the solution at 0°C, and then kept warm for 5 hours. The reaction solution was then added to a sodium chloride aqueous solution, precipitated, and filtered to obtain a polymer solid. The polymer solid was washed with pure water until its pH was neutral, and then dried at 60°C.

[0042] S2: 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 3 wt%. When the polymer solution was cooled to room temperature, 2 g of iodomethane and 1 g of sodium hydroxide were added to the polymer solution, and the mixture was stirred and reacted at 40° C. for 12 h. After the reaction, the reaction solution was added dropwise to ethyl acetate for precipitation. After filtering, the solid was washed with pure water until the pH was neutral, and then dried at 60° C. to obtain a main-chain piperidinium cationic polyelectrolyte resin.

[0043] S3: 1 g of dried main-chain piperidinium cationic polyelectrolyte resin and tetrahydrofuran were added to another round-bottom flask, and the mixture was stirred and dissolved at 60° C. to obtain a polyelectrolyte resin solution with a concentration of 3 wt%. When the polyelectrolyte resin solution was cooled to room temperature, 2 g of N-methylpiperidine was added to the polyelectrolyte resin solution, and then the mixture was stirred and reacted at 40° C. for 12 h. After the reaction was completed, the reaction solution was added dropwise to ethyl acetate for precipitation. After filtering, the solid was washed with pure water until the pH was neutral, and then dried at 60° C. to obtain a bi-type piperidinium cationic anion exchange resin.

[0044] S4: 1 g of the bis-piperidinium cationic anion exchange resin obtained in step S3 is dissolved in N,N-dimethylformamide to obtain a bis-piperidinium cationic anion exchange resin solution with a concentration of 4 wt%, and the bis-piperidinium cationic anion exchange 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 bis-piperidinium cationic anion exchange membrane is obtained.

[0045] Example 2

[0046] A method for preparing a bi-piperidinium cation anion exchange membrane, the method comprising the following steps:

[0047] 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:

[0048] Reaction precursor 1

[0049] Reaction Precursor 2

[0050] 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 sequentially added dropwise to the solution at 0°C, and then kept warm for 12 hours. The reaction solution was then added to an aqueous sodium sulfate solution, precipitated, and filtered to obtain a polymer solid. The polymer solid was washed with pure water until its pH was neutral, and then dried at 55°C.

[0051] S2: 1 g of the dried polymer solid and N,N-dimethylformamide were added to another round-bottom flask, and the mixture was stirred and dissolved at 40°C to obtain a polymer solution with a concentration of 10 wt%. When the polymer solution was cooled to room temperature, 4 g of iodomethane and 3 g of calcium hydroxide were added to the polymer solution, and then stirred and kept warm at 40°C for 36 hours. After the reaction, the reaction solution was added dropwise to ethyl acetate for precipitation. After filtering, the solid was washed with pure water until its pH was neutral, and then dried at 60°C to obtain a main-chain piperidine cationic polyelectrolyte resin;

[0052] S3: 1 g of dried main-chain piperidinium cationic polyelectrolyte resin and tetrahydrofuran were added to another round-bottom flask, and the mixture was stirred and dissolved at 60° C. to obtain a polyelectrolyte resin solution with a concentration of 8 wt%. When the polyelectrolyte resin solution was cooled to room temperature, 2 g of N-methylpiperidine was added to the polyelectrolyte resin solution, and then the mixture was stirred and reacted at 35° C. for 12 h. After the reaction was completed, the reaction solution was added dropwise to ethyl acetate for precipitation. After filtering, the solid was washed with pure water until the pH was neutral, and then dried at 60° C. to obtain a bi-type piperidinium cationic anion exchange resin.

[0053] S4: 1 g of the bipiperidinium cationic anion exchange resin obtained in step S3 is dissolved in acetonitrile to obtain a bipiperidinium cationic anion exchange resin solution having a concentration of 20 wt %. The bipiperidinium cationic anion exchange 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 bipiperidinium cationic anion exchange membrane is obtained.

[0054] Example 3

[0055] A method for preparing a bi-piperidinium cation anion exchange membrane, the method comprising the following steps:

[0056] S1: Add 10 mmol of reaction precursor 1, 90 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:

[0057] Reaction precursor 1

[0058] Reaction Precursor 2

[0059] The round-bottom flask was fixed on a magnetic stirrer device, and 7 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 sequentially 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 chloride aqueous solution for precipitation and filtration to obtain a polymer solid. The polymer solid was washed with pure water until its pH was neutral and then dried at 65°C.

[0060] S2: 1 g of the dried polymer solid and N-methylpyrrolidone were added to another round-bottom flask, and the mixture was stirred and dissolved at 40° C. to obtain a polymer solution with a concentration of 5 wt%. When the polymer solution was cooled to room temperature, 3 g of iodomethane and 2 g of potassium hydroxide were added to the polymer solution, and then the mixture was stirred and reacted at 50° C. for 24 h. After the reaction was completed, the reaction solution was added dropwise to ethyl acetate for precipitation. After filtering, the solid was washed with pure water until the pH was neutral, and then dried at 60° C. to obtain a main-chain piperidinium cationic polyelectrolyte resin;

[0061] S3: 1 g of dried main-chain piperidinium cationic polyelectrolyte resin and N-methylpyrrolidone were added to another round-bottom flask, and the mixture was stirred and dissolved at 40° C. to obtain a polyelectrolyte resin solution with a concentration of 5 wt%. When the polyelectrolyte resin solution was cooled to room temperature, 3 g of N-methylpiperidine was added to the polyelectrolyte resin solution, and then the mixture was stirred and reacted at 20° C. for 36 hours. After the reaction was completed, the reaction solution was added dropwise to ethyl acetate for precipitation. After filtering, the solid was washed with pure water until the pH was neutral, and then dried at 60° C. to obtain a bi-type piperidinium cationic anion exchange resin.

[0062] S4: 1 g of the bis-piperidinium cationic anion exchange resin obtained in step S3 is dissolved in dimethyl sulfoxide to obtain a 3 wt % bis-piperidinium cationic anion exchange resin solution, and the bis-piperidinium cationic anion exchange resin solution is cast on a glass plate and dried at 60° C. for 12 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 bis-piperidinium cationic anion exchange membrane is obtained.

[0063] Example 4

[0064] A method for preparing a bi-piperidinium cation anion exchange membrane, the method comprising the following steps:

[0065] 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:

[0066] Reaction precursor 1

[0067] Reaction Precursor 2:

[0068] The round-bottom flask was fixed on a magnetic stirrer device, 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 sequentially added dropwise to the solution at 5°C, and then kept warm for 5 hours. The reaction solution was then added to a potassium chloride aqueous solution, precipitated, and filtered to obtain a polymer solid. The polymer solid was washed with pure water until its pH was neutral, and then dried at 55°C.

[0069] S2: 1 g of dried polymer solid and N,N-dimethylacetamide were added to another round-bottom flask, and the mixture was stirred and dissolved at 40°C to obtain a polymer solution with a concentration of 3 wt%. When the polymer solution was cooled to room temperature, 1 g of iodomethane and 0.5 g of potassium hydroxide were added to the polymer solution, and then stirred and kept warm at 50°C for 12 hours. After the reaction, the reaction solution was added dropwise to ethyl acetate for precipitation. After filtering, the solid was washed with pure water until its pH was neutral, and then dried at 55°C to obtain a main-chain piperidine cationic polyelectrolyte resin;

[0070] S3: 1 g of dried main-chain piperidinium cationic polyelectrolyte resin and N-methylpyrrolidone were added to another round-bottom flask, and the mixture was stirred and dissolved at 60° C. to obtain a polyelectrolyte resin solution with a concentration of 3 wt%. When the polyelectrolyte resin solution was cooled to room temperature, 5 g of N-methylpiperidine was added to the polyelectrolyte resin solution, and then the mixture was stirred and reacted at 40° C. for 30 h. After the reaction was completed, the reaction solution was added dropwise to ethyl acetate for precipitation. After filtering, the solid was washed with pure water until the pH was neutral, and then dried at 60° C. to obtain a bi-type piperidinium cationic anion exchange resin.

[0071] S4: 1 g of the bi-piperidinium cationic anion exchange resin obtained in step S3 is dissolved in tetrahydrofuran to obtain a bi-piperidinium cationic anion exchange resin solution with a concentration of 10 wt %, and the bi-piperidinium cationic anion exchange 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 10 h. After drying, a bi-piperidinium cationic anion exchange membrane is obtained.

[0072] Example 5

[0073] A method for preparing a bi-piperidinium cation anion exchange membrane, the method comprising the following steps:

[0074] 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:

[0075] Reaction precursor 1

[0076] Reaction Precursor 2

[0077] 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. 5 mL of trifluoroacetic acid and 10 mL of trifluoromethanesulfonic acid were sequentially added dropwise to the solution at -5°C, and then the reaction was kept warm for 24 hours. The reaction solution was then added to a sodium chloride aqueous solution, precipitated, and filtered to obtain a polymer solid. The polymer solid was washed with pure water until its pH was neutral, and then dried at 60°C.

[0078] S2: 1 g of the dried polymer solid and acetonitrile 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 20 wt%. When the polymer solution was cooled to room temperature, 5 g of iodomethane and 5 g of sodium hydroxide were added to the polymer solution, and then stirred and kept warm at 20° C. for 48 h. After the reaction, the reaction solution was added dropwise to ethyl acetate for precipitation. After filtering, the solid was washed with pure water until the pH was neutral, and then dried at 65° C. to obtain a main-chain piperidinium cationic polyelectrolyte resin.

[0079] S3: 1 g of dried main-chain piperidinium cationic polyelectrolyte resin and dimethyl sulfoxide were added to another round-bottom flask, and the mixture was stirred and dissolved at 60° C. to obtain a polyelectrolyte resin solution with a concentration of 12 wt%. When the polyelectrolyte resin solution was cooled to room temperature, 1 g of N-methylpiperidine was added to the polyelectrolyte resin solution, and then the mixture was stirred and reacted at 40° C. for 12 h. After the reaction was completed, the reaction solution was added dropwise to ethyl acetate for precipitation. After filtering, the solid was washed with pure water until the pH was neutral, and then dried at 60° C. to obtain a bi-type piperidinium cationic anion exchange resin.

[0080] S4: 1 g of the bipiperidinium cationic anion exchange resin obtained in step S3 was dissolved in dimethyl sulfoxide to obtain a bipiperidinium cationic anion exchange resin solution with a concentration of 3 wt %, and the polyelectrolyte resin solution was cast on a glass plate and dried at 80° C. for 24 h to form a film. The dried film was then placed in a 1 mol / L potassium hydroxide aqueous solution and soaked at 65° C. for 48 h. After being taken out, the residual potassium hydroxide was washed with pure water, and the film was 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 10 h. After drying, a bipiperidinium cationic anion exchange membrane was obtained.

[0081] Example 6

[0082] A method for preparing a bi-piperidinium cation anion exchange membrane, the method comprising the following steps:

[0083] S1: Add 40 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:

[0084] Reaction precursor 1

[0085] Reaction Precursor 2

[0086] 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. 5 mL of trifluoroacetic acid and 10 mL of trifluoromethanesulfonic acid were sequentially added dropwise to the solution at 2°C. The mixture was then kept warm for 22 hours. The reaction solution was then added to a sodium chloride aqueous solution for precipitation and filtration to obtain a polymer solid. The polymer solid was washed with pure water until its pH was neutral and then dried at 60°C.

[0087] S2: 1 g of the dried polymer solid and dimethyl sulfoxide were added to another round-bottom flask, and the mixture was stirred and dissolved at 70° C. to obtain a polymer solution with a concentration of 15 wt%. When the polymer solution was cooled to room temperature, 4 g of iodomethane and 4 g of calcium hydroxide were added to the polymer solution, and then stirred and kept warm at 30° C. for 40 h. After the reaction was completed, the reaction solution was added dropwise to ethyl acetate for precipitation. After filtering, the solid was washed with pure water until its pH was neutral, and then dried at 60° C. to obtain a main-chain piperidinium cationic polyelectrolyte resin;

[0088] S3: 1 g of dried main-chain piperidinium cationic polyelectrolyte resin and N,N-dimethylformamide were added to another round-bottom flask, and the mixture was stirred and dissolved at 65° C. to obtain a polyelectrolyte resin solution with a concentration of 15 wt%. When the polyelectrolyte resin solution was cooled to room temperature, 4 g of N-methylpiperidine was added to the polyelectrolyte resin solution, and then the mixture was stirred and reacted at 40° C. for 36 hours. After the reaction was completed, the reaction solution was added dropwise to ethyl acetate for precipitation. After filtering, the solid was washed with pure water until the pH was neutral, and then dried at 60° C. to obtain a bi-type piperidinium cationic anion exchange resin.

[0089] S4: 1 g of the bis-piperidinium cationic anion exchange resin obtained in step S3 is dissolved in N,N-dimethylacetamide to obtain a bis-piperidinium cationic anion exchange resin solution with a concentration of 15 wt%, and the bis-piperidinium cationic anion exchange resin solution is cast on a glass plate and dried at 75° C. for 12 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 30 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 bis-piperidinium cationic anion exchange membrane is obtained.

[0090] Example 7

[0091] A method for preparing a bi-piperidinium cation anion exchange membrane, the method comprising the following steps:

[0092] 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:

[0093] Reaction precursor 1

[0094] Reaction Precursor 2

[0095] 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 an aqueous sodium sulfate solution for precipitation and filtration to obtain a polymer solid. The polymer solid was washed with pure water until its pH was neutral and then dried at 60°C.

[0096] S2: 1 g of the dried polymer solid and dimethyl sulfoxide were added to another round-bottom flask, and the mixture was stirred and dissolved at 80° C. to obtain a polymer solution with a concentration of 20 wt%. When the polymer solution was cooled to room temperature, 4 g of iodomethane and 4 g of potassium hydroxide were added to the polymer solution, and the mixture was stirred and reacted at 50° C. for 12 h. After the reaction, the reaction solution was added dropwise to ethyl acetate for precipitation. After filtering, the solid was washed with pure water until the pH was neutral, and then dried at 60° C. to obtain a main-chain piperidinium cationic polyelectrolyte resin.

[0097] S3: 1 g of dried main-chain piperidinium cationic polyelectrolyte resin and tetrahydrofuran were added to another round-bottom flask, and the mixture was stirred and dissolved at 60° C. to obtain a polyelectrolyte resin solution with a concentration of 20 wt%. When the polyelectrolyte resin solution was cooled to room temperature, 4 g of N-methylpiperidine was added to the polyelectrolyte resin solution, and then the mixture was stirred and reacted at 50° C. for 48 h. After the reaction was completed, the reaction solution was added dropwise to ethyl acetate for precipitation. After filtering, the solid was washed with pure water until the pH was neutral, and then dried at 60° C. to obtain a bi-type piperidinium cationic anion exchange resin.

[0098] S4: 1 g of the bis-piperidinium cationic anion exchange resin obtained in step S3 is dissolved in N,N-dimethylformamide to obtain a bis-piperidinium cationic anion exchange resin solution with a concentration of 27 wt%, and the bis-piperidinium cationic anion exchange 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 bis-piperidinium cationic anion exchange membrane is obtained.

[0099] Example 8

[0100] A method for preparing a bi-piperidinium cation anion exchange membrane, the method comprising the following steps:

[0101] 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:

[0102] Reaction precursor 1:

[0103] Reaction Precursor 2

[0104] The round-bottom flask was fixed on a magnetic stirrer, and 7 mL of dichloromethane was added and stirred to dissolve the reaction precursor. 1 mL of trifluoroacetic acid and 7 mL of trifluoromethanesulfonic acid were sequentially added dropwise to the solution at -3°C, and then the reaction was kept warm for 7 hours. The reaction solution was then added to an aqueous sodium sulfate solution, precipitated, and filtered to obtain a polymer solid. The polymer solid was washed with pure water until its pH was neutral, and then dried at 60°C.

[0105] S2: 1 g of the dried polymer solid and tetrahydrofuran were added to another round-bottom flask, and the mixture was stirred and dissolved at 80° C. to obtain a polymer solution with a concentration of 7 wt%. When the polymer solution was cooled to room temperature, 2 g of iodomethane and 2 g of aqueous ammonia were added to the polymer solution, and then stirred and kept warm at 50° C. for 17 h. After the reaction, the reaction solution was added dropwise to ethyl acetate for precipitation. After filtering, the solid was washed with pure water until its pH was neutral, and then dried at 58° C. to obtain a main-chain piperidinium cationic polyelectrolyte resin;

[0106] S3: 1 g of dried main-chain piperidinium cationic polyelectrolyte resin and tetrahydrofuran were added to another round-bottom flask, and the mixture was stirred and dissolved at 60° C. to obtain a polyelectrolyte resin solution with a concentration of 5 wt%. When the polyelectrolyte resin solution was cooled to room temperature, 3 g of N-methylpiperidine was added to the polyelectrolyte resin solution, and then the mixture was stirred and reacted at 40° C. for 12 h. After the reaction was completed, the reaction solution was added dropwise to ethyl acetate for precipitation. After filtering, the solid was washed with pure water until the pH was neutral, and then dried at 60° C. to obtain a bi-type piperidinium cationic anion exchange resin.

[0107] S4: 1 g of the bis-piperidinium cationic anion exchange resin obtained in step S3 is dissolved in N,N-dimethylformamide to obtain a 5 wt% bis-piperidinium cationic anion exchange resin solution, 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 bis-piperidinium cationic anion exchange membrane is obtained.

[0108] Example 9

[0109] A method for preparing a bi-piperidinium cation anion exchange membrane, the method comprising the following steps:

[0110] S1: Add 20 mmol of reaction precursor 1, 60 mmol of reaction precursor 2, and 105 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:

[0111] Reaction precursor 1

[0112] Reaction Precursor 2

[0113] 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. 5 mL of trifluoroacetic acid and 10 mL of trifluoromethanesulfonic acid were sequentially added dropwise to the solution at 4°C, and the mixture was kept warm for 15 hours. The reaction solution was then added to a potassium chloride aqueous solution, precipitated, and filtered to obtain a polymer solid. The polymer solid was washed with pure water until its pH was neutral, and then dried at 65°C.

[0114] S2: 1 g of the dried polymer solid and N-methylpyrrolidone were added to another round-bottom flask, and the mixture was stirred and dissolved at 50° C. to obtain a polymer solution with a concentration of 8 wt%. When the polymer solution was cooled to room temperature, 2 g of iodomethane and 1 g of calcium hydroxide were added to the polymer solution, and then stirred and kept warm at 30° C. for 20 h. After the reaction, the reaction solution was added dropwise to ethyl acetate for precipitation. After filtering, the solid was washed with pure water until its pH was neutral, and then dried at 60° C. to obtain a main-chain piperidinium cationic polyelectrolyte resin;

[0115] S3: 1 g of dried main-chain piperidinium cationic polyelectrolyte resin and tetrahydrofuran were added to another round-bottom flask, and the mixture was stirred and dissolved at 50° C. to obtain a polyelectrolyte resin solution with a concentration of 3 wt%. When the polyelectrolyte resin solution was cooled to room temperature, 2 g of N-methylpiperidine was added to the polyelectrolyte resin solution, and then the mixture was stirred and reacted at 40° C. for 25 h. After the reaction was completed, the reaction solution was added dropwise to ethyl acetate for precipitation. After filtering, the solid was washed with pure water until the pH was neutral, and then dried at 60° C. to obtain a bi-type piperidinium cationic anion exchange resin.

[0116] S4: 1 g of the bipiperidinium cationic anion exchange resin obtained in step S3 was dissolved in N-methylpyrrolidone to obtain a bipiperidinium cationic anion exchange resin solution having a concentration of 30 wt %. The bipiperidinium cationic anion exchange resin solution was cast on a glass plate and dried at 65° C. for 18 h to form a film. The dried film was then placed in a 1 mol / L potassium hydroxide aqueous solution and soaked at 60° C. for 22 h. After being taken out, the residual potassium hydroxide was washed with pure water, and the film was 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 10 h. After drying, a bipiperidinium cationic anion exchange membrane was obtained.

[0117] Comparative Example 1

[0118] A method for preparing an anion exchange membrane, the method comprising the following steps:

[0119] S1: Add 5 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:

[0120] Reaction precursor 1

[0121] Reaction Precursor 2

[0122] The round-bottom flask was fixed on a magnetic stirrer device, 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. 1 mL of trifluoroacetic acid and 5 mL of trifluoromethanesulfonic acid were sequentially added dropwise to the solution at 0°C, and then kept warm for 5 hours. The reaction solution was then added to a sodium chloride aqueous solution, precipitated, and filtered to obtain a polymer solid. The polymer solid was washed with pure water until its pH was neutral, and then dried at 60°C.

[0123] S2: Add 1 g of the dried polymer solid and tetrahydrofuran to another round-bottom flask, stir and dissolve at 60°C to obtain a polymer solution with a concentration of 3 wt%. When the polymer solution is cooled to room temperature, add 2 g of iodomethane and 1 g of sodium hydroxide to the polymer solution, and keep stirring at 40°C for 12 hours. After the reaction is completed, add the reaction solution dropwise to ethyl acetate for precipitation. After filtering, wash the solid with pure water until its pH is neutral, and then dry it at 60°C to obtain a polyelectrolyte resin.

[0124] S3: Take 1 g of the polyelectrolyte resin obtained in step S2 and dissolve it in N,N-dimethylformamide to obtain a polyelectrolyte resin solution with a concentration of 4 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, the film is obtained.

[0125] Test example

[0126] The bi-piperidinium cation anion exchange membranes prepared in the examples of the present invention have similar performances. Examples 1 to 3 are used as examples to illustrate the performances of related products.

[0127] 1. Conductivity test

[0128] The samples prepared in Examples 1 to 3 and Comparative Example 1 were cut into rectangular film 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 Hz. Then, the conductivity is calculated based on the Nyquist diagram of the test results. The results are as follows Figure 1 As shown in the figure, it can be seen that the conductivity of the bi-piperidinium cation anion exchange membrane in the embodiment is significantly greater than the conductivity of the sample in Comparative Example 1. At 30°C, its conductivity can be as high as 167.3mS / cm, and its conductivity increases with increasing temperature, reaching 180-240mS / cm at 60°C and 90°C.

[0129] 2. Mechanical properties test

[0130] The samples prepared in Examples 1 to 3 and Comparative Example 1 were cut into rectangular film strips of 4 cm × 1 cm and tested using an MTS tensile testing machine (E44.104) at room temperature and a tensile speed of 5 mm min -1 , the results are as follows Figure 2 As shown in the figure, it can be seen that the yield stage and the strengthening stage of the stress-strain curve of the bi-piperidinium cationic anion exchange membrane in the embodiment are later than those in the comparative example, and it can be concluded that the mechanical properties of the bi-piperidinium cationic anion exchange membrane in the embodiment are better.

[0131] 3. Alkali resistance stability test

[0132] The samples prepared in Examples 1 to 3 and Comparative Example 1 were immersed in a 1 mol / L KOH solution at 80°C for 1000 hours to test the degradation rate of the cationic groups. Figure 3 As shown in the figure, it can be seen that the cationic group degradation rate of the bipiperidinium cationic anion exchange membrane in the embodiment after immersion for 1000 hours is significantly lower than that of the comparative example sample, indicating that the bipiperidinium cationic anion exchange membrane in the embodiment has better alkali resistance and stability.

[0133] 4. Water absorption and swelling test

[0134] The samples prepared in Examples 1 to 3 and Comparative Example 1 were subjected to water absorption and swelling tests, and the dry films and wet films at different temperatures were tested for weight and length changes. The results are shown in FIG. Figure 4 and Figure 5As shown in the figure, it can be seen that the water absorption and swelling ratio of the bi-piperidinium cation anion exchange membrane in the embodiment are significantly smaller than those in the comparative example.

[0135] 5. Battery performance test

[0136] 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. Then, 20 μL of a 5 wt% bis-piperidinium cationic anion exchange resin solution prepared from the bis-piperidinium cationic anion exchange 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 onto both sides of the bis-piperidinium cationic 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 (850e Multi Range, Scribner Associates Co) for battery performance testing.

[0137] The test conditions are: battery temperature 80℃, pure hydrogen as fuel, pure oxygen as oxidant, the results are as follows Figure 6 As shown in the figure, it can be seen that the bi-piperidinium cationic anion exchange membrane in Example 1 exhibits excellent battery performance, with a peak power density of up to 1.38 W / cm 2 .

[0138] 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 method for preparing a bi-type piperidinium cationic anion exchange membrane, characterized in that: The following steps are involved: 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 a neutral solution, washed and dried to obtain a polymer solid. The reaction precursor 1 is one of the compounds represented by formula (I), wherein n is an integer from 1 to 15. The reaction precursor 2 is one of the compounds represented by formula (II), S2: dissolving the polymer solid in a polar solvent to obtain a polymer solution having a concentration of 3 to 20 wt%, adding methyl iodide and an alkaline substance to the polymer solution, reacting at 20 to 50° C. for 12 to 48 hours, adding the reaction solution dropwise to the solvent for precipitation, and then filtering, washing, and drying to obtain a main-chain piperidinium cationic polyelectrolyte resin; S3: dissolving the main chain piperidinium cationic polyelectrolyte resin in a polar solvent to obtain a polyelectrolyte resin solution with a concentration of 3 to 20 wt%, adding N-methylpiperidine to the polyelectrolyte resin solution, reacting at 20 to 50° C. for 12 to 48 hours, adding the reaction solution dropwise to the solvent for precipitation, and then filtering, washing, and drying to obtain a bi-type piperidinium cationic anion exchange resin; S4: dissolving the bis-piperidinium cationic anion exchange resin in a polar solvent to obtain a bis-piperidinium cationic anion exchange resin solution with a concentration of 3 to 30 wt%, casting the bis-piperidinium cationic anion exchange 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.

2. The method for preparing a bimorphous piperidinium cationic anion exchange membrane according to claim 1, 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: 50-95 mmol: 100-130 mmol: 5-10 ml: 1-5 ml: 5-10 ml; the solvent in step S1 is dichloromethane.

3. The method for preparing a bimorphous piperidinium cationic anion exchange membrane according to claim 1, wherein: The reaction time in step S1 is 5 to 24 hours; the neutral solution is at least one of NaCl, KCl and Na2SO4 aqueous solutions; and the drying temperature in steps S1, S2 and S3 is 55 to 65°C.

4. The method for preparing a bi-type piperidinium cationic anion exchange membrane according to claim 1, wherein: The alkaline substance in step S2 is at least one of KOH, NaOH, NH3·H2O and Ca(OH)2, and the mass ratio of the polymer solid, the alkaline substance and iodomethane is 1:0.5~5:1~5; the polar solvent in steps S2, S3 and S4 is at least one of tetrahydrofuran, acetonitrile, N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide and dimethyl sulfoxide.

5. The method for preparing a bi-piperidinium cationic anion exchange membrane according to claim 1, wherein: The solvent in steps S2 and S3 is ethyl acetate.

6. The method for preparing a bi-piperidinium cationic anion exchange membrane according to claim 1, wherein: In step S3, the mass ratio of N-methylpiperidine to the main chain piperidinium cationic polyelectrolyte resin is 1 to 5:

1.

7. The method for preparing a bi-piperidinium cationic anion exchange membrane according to claim 1, wherein: In step S4, the drying temperature is 50-80° C., and the drying time is 8-24 hours; the alkaline solution 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.

8. The bi-piperidinium cationic anion exchange membrane according to claim 1, characterized in that: The drying temperature in step S4 is 45-55°C.

9. A bipiperidinium cationic anion exchange membrane prepared by the method for preparing a bipiperidinium cationic anion exchange membrane according to any one of claims 1 to 8.

10. Use of the bi-piperidinium cationic anion exchange membrane according to claim 9 in the preparation of alkaline fuel cell materials, carbon dioxide reduction electrolyte materials or alkaline water electrolysis materials.

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