Biimidazole cation alkaline anion exchange membrane based on polyphenylene ether and preparation method thereof

Abstract

The invention belongs to the field of anion exchange membrane preparation of a fuel cell and particularly relates to a biimidazole cation alkaline anion exchange membrane based on polyphenylene ether and a preparation method thereof. The anion exchange membrane with relatively high ion conductivity, heat stability, chemical stability and mechanical property is prepared through a simple environmental-friendly preparation method.

Description

technical field

[0001] The invention belongs to the field of preparation of anion exchange membranes for fuel cells, in particular to a polyphenylene ether-based bisimidazolium cation alkaline anion exchange membrane and a preparation method thereof. Background technique

[0002] Anion exchange membranes consist of matrix materials and active groups, and are widely used in water treatment, chemical separation, and alkaline fuel cells. The common preparation method of the traditional anion exchange membrane is to chloromethylate the commercially available polymer, and then carry out reactions such as quaternization and anion exchange. Among them, the highly toxic carcinogen chloromethyl ether will be used in the chloromethylation process, which is very harmful to the environment and the human body. Moreover, the thermal stability and chemical stability of traditional polymer anion exchange membranes are low. Under high temperature or alkaline conditions, the quaternary ammon...

Examples

Embodiment 1

[0026] Dissolve 3.00g (36.50mmol) 2-methylimidazole in 25ml acetonitrile, add 4.45g (18.25mmol) 1,6-dibromohexane and 4.1g (73.00mmol) KOH, nitrogen protection, room temperature (25°C, The same below), reacted for 24 hours, dissolved the crude product in water, extracted the crude product with dichloromethane, repeated three times, and dried the product to obtain a white solid product;

[0027] 1.00g (4.06mmol) of the white solid product prepared above and 0.58g (4.06mmol) of methyl iodide were dissolved in 25ml of ethyl acetate, reacted at room temperature for 4 hours, separated and purified to obtain the functional monomer containing the biimidazole structure, the molecule The structure is:

[0028]

[0029] The preparation of other functional monomers containing bis-imidazole structure can also refer to this preparation method.

Embodiment 2

[0031] 0.4g (2.86mmol) bromination degree is 25% BrPPO and 0.74g (2.86mol) prepared in Example 1 Dissolve in 25ml of N-methylpyrrolidone, react at 30°C for 6 hours, place the mixed solution in a polytetrafluoroethylene template, and dry at 70°C for 2 hours to prepare a halogen-type anion exchange membrane;

[0032] Place the obtained halogen-type anion exchange membrane in 1M KOH solution and soak it at 60°C for 24 hours. After the halogen anion is completely exchanged into OH-, remove the residual KOH with deionized water to obtain the OH-type anion-exchange membrane.

[0033] The OH-type anion exchange membrane obtained in this example has a water absorption rate of 55.56%, a swelling degree of 21.36%, an ion exchange capacity of 1.25 mmol / g, and an ion conductivity of 11.57 mS cm at room temperature. -1 , the ion conductivity at 90°C is 32.40mS·cm -1 .

[0034] The membrane was immersed in 1M KOH solution for 400 hours, and its conductivity was measured again. The ion co...

Embodiment 3

[0036] 0.4g (2.71mmol) of BrPPO with a bromination degree of 35% and 0.67g (2.71mmol) Dissolve in 25ml of N-methylpyrrolidone, react at 50°C for 4 hours, place the mixed solution in a polytetrafluoroethylene template, and dry at 70°C for 2 hours to prepare a halogen-type anion exchange membrane;

[0037] Place the obtained halogen-type anion exchange membrane in 1M KOH solution and soak it at 60°C for 24 hours. After the halogen anion is completely exchanged into OH-, remove the residual KOH with deionized water to obtain the OH-type anion-exchange membrane.

[0038] The OH-type anion exchange membrane obtained in this example has a water absorption rate of 58.14%, a swelling degree of 21.58%, an ion exchange capacity of 1.31 mmol / g, and an ion conductivity of 14.23 mS cm at room temperature. -1 , the ion conductivity at 90°C is 35.02mS·cm -1 .

[0039] The membrane was immersed in 1M KOH solution for 400 hours, and its conductivity was measured again. The ion conductivity ...

technical field

[0001] The invention belongs to the field of preparation of anion exchange membranes for fuel cells, in particular to a polyphenylene ether-based bisimidazolium cation alkaline anion exchange membrane and a preparation method thereof. Background technique

[0002] Anion exchange membranes consist of matrix materials and active groups, and are widely used in water treatment, chemical separation, and alkaline fuel cells. The common preparation method of the traditional anion exchange membrane is to chloromethylate the commercially available polymer, and then carry out reactions such as quaternization and anion exchange. Among them, the highly toxic carcinogen chloromethyl ether will be used in the chloromethylation process, which is very harmful to the environment and the human body. Moreover, the thermal stability and chemical stability of traditional polymer anion exchange membranes are low. Under high temperature or alkaline conditions, the quaternary ammon...

Examples

Embodiment 1

[0026] Dissolve 3.00g (36.50mmol) 2-methylimidazole in 25ml acetonitrile, add 4.45g (18.25mmol) 1,6-dibromohexane and 4.1g (73.00mmol) KOH, nitrogen protection, room temperature (25°C, The same below), reacted for 24 hours, dissolved the crude product in water, extracted the crude product with dichloromethane, repeated three times, and dried the product to obtain a white solid product;

[0027] 1.00g (4.06mmol) of the white solid product prepared above and 0.58g (4.06mmol) of methyl iodide were dissolved in 25ml of ethyl acetate, reacted at room temperature for 4 hours, separated and purified to obtain the functional monomer containing the biimidazole structure, the molecule The structure is:

[0028]

[0029] The preparation of other functional monomers containing bis-imidazole structure can also refer to this preparation method.

Embodiment 2

[0031] 0.4g (2.86mmol) bromination degree is 25% BrPPO and 0.74g (2.86mol) prepared in Example 1 Dissolve in 25ml of N-methylpyrrolidone, react at 30°C for 6 hours, place the mixed solution in a polytetrafluoroethylene template, and dry at 70°C for 2 hours to prepare a halogen-type anion exchange membrane;

[0032] Place the obtained halogen-type anion exchange membrane in 1M KOH solution and soak it at 60°C for 24 hours. After the halogen anion is completely exchanged into OH-, remove the residual KOH with deionized water to obtain the OH-type anion-exchange membrane.

[0033] The OH-type anion exchange membrane obtained in this example has a water absorption rate of 55.56%, a swelling degree of 21.36%, an ion exchange capacity of 1.25 mmol / g, and an ion conductivity of 11.57 mS cm at room temperature. -1 , the ion conductivity at 90°C is 32.40mS·cm -1 .

[0034] The membrane was immersed in 1M KOH solution for 400 hours, and its conductivity was measured again. The ion co...

Embodiment 3

[0036] 0.4g (2.71mmol) of BrPPO with a bromination degree of 35% and 0.67g (2.71mmol) Dissolve in 25ml of N-methylpyrrolidone, react at 50°C for 4 hours, place the mixed solution in a polytetrafluoroethylene template, and dry at 70°C for 2 hours to prepare a halogen-type anion exchange membrane;

[0037] Place the obtained halogen-type anion exchange membrane in 1M KOH solution and soak it at 60°C for 24 hours. After the halogen anion is completely exchanged into OH-, remove the residual KOH with deionized water to obtain the OH-type anion-exchange membrane.

[0038] The OH-type anion exchange membrane obtained in this example has a water absorption rate of 58.14%, a swelling degree of 21.58%, an ion exchange capacity of 1.31 mmol / g, and an ion conductivity of 14.23 mS cm at room temperature. -1 , the ion conductivity at 90°C is 35.02mS·cm -1 .

[0039] The membrane was immersed in 1M KOH solution for 400 hours, and its conductivity was measured again. The ion conductivity ...

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