CN102050911A - Polymer anion exchange membrane and preparation method thereof - Google Patents

Abstract

The invention relates to a polymer anion exchange membrane and a preparation method thereof, in particular to an anion exchange membrane capable of being used for an alkaline fuel cell and a preparation method thereof. The preparation method comprises the following steps of: mixing a polymer monomer and polymeric ionic liquid in a mole ratio of 1:2-1:9; adding a cross-linking agent and an initiating agent; carrying out ultrasound on the mixed liquor to ensure that the mixed liquor is mixed uniformly; and carrying out in-situ polymerization to prepare the polymer anion exchange membrane, wherein the monomer is a mixture which is selected from one or more than two of acrylonitrile, styrene, alpha-methyl styrene, and alpha-methacrylonitrile. The preparation method is simple, more economic and more environment-friendly; compared with the anion exchange membrane reported in the prior art, the obtained anion exchange membrane can guarantee higher ionic conductivity, good alkali-resisting property, good heat stability and chemical stability, and can furthermore obtain good mechanical property.

Description

A kind of polymer anion exchange membrane and preparation method thereof

technical field

The invention relates to a polymer anion exchange membrane and a preparation method thereof, in particular to an anion exchange membrane which can be used in an alkaline fuel cell and a preparation method thereof.

Background technique

Anion exchange membranes have been widely used in industrial fields such as water treatment, hydrometallurgy, chemical separation and alkaline fuel cells. The traditional preparation method of quaternary ammonium salt type polymer anion exchange membrane must go through the process of chloromethylation when introducing ion exchange groups, and the highly toxic carcinogen chloromethyl ether is used in the chloromethylation process, and in Organic solvents are used in the process of preparing anion exchange membranes, which have great harm to environmental protection and human health.

The Chinese invention application publication with the application number of 201010185161.4 discloses a preparation method of anion exchange membrane based on ionic liquid, which is to add imidazole ionic liquid, acrylate monomer, solvent and initiator in the reactor under the protection of inert gas. Polymerize at 45-80°C for 5-30 hours, then dissolve the polymer in an organic solvent to prepare a polymer solution, and form a film by phase inversion. The above-mentioned methods all have the use of solvent in the process of polymerization and film formation. The use of solvent makes the preparation process of anion exchange membrane complicated, increases the production cost, and also causes certain pollution to the environment. In addition, in the selection of matrix material and in the anion The ion exchange capacity of the anion exchange membrane is low due to the exchange treatment process. Therefore, people have been looking for an anion exchange membrane preparation method with simple process, environmental friendliness, low production cost and good performance.

Excellent polymer anion exchange membranes for alkaline fuel cells not only have high ionic conductivity, good thermal and chemical stability, but also good mechanical properties and alkali resistance. However, the traditional quaternary ammonium salt type polymer anion exchange membrane has poor thermal and chemical stability. Quaternary ammonium groups have poor stability in alkaline solutions, which greatly reduces the performance of anion exchange membranes. The above-mentioned published description of the invention application also does not disclose data related to mechanical properties.

Therefore, it is necessary to develop a polymer anion exchange membrane material that can be used in alkaline fuel cells.

Contents of the invention

The purpose of the present invention is to provide a polymer anion exchange membrane and its preparation method, through an economical, simple and environmentally friendly preparation method to obtain a membrane with high ion conductivity, good thermal stability and chemical stability, good Excellent mechanical properties and alkali resistance of polymeric anion exchange membranes.

In order to achieve the above object, the technical scheme adopted in the present invention is: a kind of preparation method of alkaline anion exchange membrane, comprises the following steps:

1. Mix the polymer monomer and the polymeric ionic liquid at a molar ratio of 1:2 to 1:9, then add a crosslinking agent and an initiator, mix the mixed solution uniformly by ultrasonic, and perform in-situ polymerization to prepare a polymer anion exchange membrane;

The monomer is selected from one or more of acrylonitrile, styrene, α-methylstyrene, and α-methacrylonitrile;

The polymeric ionic liquid is selected from:

中的一种，其中m＝0～10，p＝0～6，X选自：I、Br或Cl中的一种；

One of, wherein m=0～10, p=0～6, X is selected from: one of I, Br or Cl;

2. Soak the prepared anion exchange membrane in alkali solution at 50-80°C for anion exchange; wherein, the ionic liquid is an ionic liquid with polymeric aromatic heterocyclic structure; the lye is 1-10M potassium hydroxide or an aqueous solution of sodium hydroxide;

In the above technical solution, the crosslinking agent is selected from divinylbenzene, and the mass of the crosslinking agent is 2% to 12% of the sum of the mass of the polymer monomer and the polymeric ionic liquid.

In the above technical scheme, the initiator is selected from: benzoin ether, azobisisobutyronitrile, One of them; the mass of the initiator is 1% to 6% of the sum of the mass of the polymer monomer and the polymeric ionic liquid.

In the above technical solution, the polymerization reaction is initiated by heating, ultraviolet light or gamma rays.

The present invention also claims to protect the ionic liquid-based polymer anion exchange membrane prepared by the above method, and the anion exchange membrane can be applied in the field of alkaline fuel cells.

Due to the use of the above-mentioned technical solutions, the present invention has the following advantages compared with the prior art:

1, because the present invention has adopted the in-situ synthesis method, and has avoided the use of chloromethyl ether in the preparation process of traditional polymer anion exchange membrane, has avoided the use of organic solvent in the anion exchange membrane process of solution casting film formation method simultaneously, Therefore, the method is simple, more economical, and more environmentally friendly;

2. The ion exchange capacity of the OH-type anion exchange membrane obtained in the present invention can reach 1.52mmol/g, the ion conductivity can reach 3.60×10 ^-2 S·cm ^-1 at room temperature, and the ion conductivity can reach 7.53×10 ^-2 S·cm ^-1 , the tensile strength can reach 13.53Mpa, the Young's modulus can reach 1271Mpa, and the elongation at break can reach 55.34%. It has high ionic conductivity, good alkali resistance, good thermal stability and chemical stability, and also has good mechanical properties.

Description of drawings

Fig. 1 is the change diagram of conductivity with temperature of anion exchange membrane soaked in 1M KOH solution at 60°C for different time in Example 11.

Detailed ways

The present invention will be further described below in conjunction with accompanying drawing and embodiment:

Embodiment one:

0.20g(0.85mmol)，苯乙烯0.10g(0.96mmol)，丙烯腈0.20g(3.73mmol)，安息香乙醚0.01g，二乙烯基苯0.02g，将溶液混合均匀，涂到模具上，紫外光照(波长240nm-380nm)30min，原位聚合成膜。然后将该阴离子交换膜浸泡在50℃1M KOH溶液中24小时，将阴离子转换成OH^-，本实施例获得的OH^-型阴离子交换膜离子交换容量为1.47mmol/g，室温下离子传导率为3.13×10^-2S·cm^-1，90℃下离子传导率为6.53×10^-2S·cm^-1。抗张强度为11.41Mpa，杨氏模量为439.9Mpa，断裂伸长率为52.65％。

0.20g (0.85mmol), 0.10g (0.96mmol) of styrene, 0.20g (3.73mmol) of acrylonitrile, 0.01g of benzoin ethyl ether, 0.02g of divinylbenzene, mix the solution evenly, apply it on the mold, and irradiate with ultraviolet light ( Wavelength 240nm-380nm) 30min, in-situ polymerization to form a film. Then soak the anion exchange membrane in 1M KOH solution at 50°C for 24 hours to convert the anions into OH ^- . The ion exchange capacity of the OH ^- type anion exchange membrane obtained in this example is 1.47mmol/g, and the ion conductivity at room temperature is 3.13×10 ^-2 S·cm ^-1 , and the ion conductivity at 90°C is 6.53×10 ^-2 S·cm ^-1 . The tensile strength is 11.41Mpa, the Young's modulus is 439.9Mpa, and the elongation at break is 52.65%.

Embodiment two:

0.20g(0.85mmol)，丙烯腈0.30g(5.60mmol)，安息香乙醚0.01g，二乙烯基苯0.02g，将溶液混合均匀，涂到模具上，紫外光照(波长240nm-380nm)30min，原位聚合成膜。然后将该阴离子交换膜浸泡在60℃5MKOH溶液中24小时，将阴离子转换成OH^-，本实施例获得的OH^-型阴离子交换膜离子交换容量为1.52mmol/g，室温下离子传导率为3.60×10^-2S·cm^-1，90℃下离子传导率为7.53×10^-2S·cm^-1。抗张强度为10.23Mpa，杨氏模量为521.34Mpa，断裂伸长率为55.34％。

0.20g (0.85mmol), 0.30g (5.60mmol) of acrylonitrile, 0.01g of benzoin ethyl ether, 0.02g of divinylbenzene, mix the solution evenly, apply it on the mold, irradiate with ultraviolet light (wavelength 240nm-380nm) for 30min, in situ Polymerize into film. Then soak the anion exchange membrane in 5M KOH solution at 60°C for 24 hours to convert the anions into OH ^- . The ion exchange capacity of the OH ^- type anion exchange membrane obtained in this example is 1.52 mmol/g, and the ion conductivity at room temperature is 3.60 ×10 ^-2 S·cm ^-1 , and the ion conductivity at 90°C is 7.53×10 ^-2 S·cm ^-1 . The tensile strength is 10.23Mpa, the Young's modulus is 521.34Mpa, and the elongation at break is 55.34%.

Embodiment three:

0.20g(0.87mmol)，丙烯腈0.30g(5.60mmol)，安息香乙醚0.01g，偶氮二异丁腈0.02g，将溶液混合均匀，涂到模具上，75℃下聚合6个小时，原位聚合成膜。然后将该阴离子交换膜浸泡在60℃ 10M KOH溶液中将阴离子转换成OH^-，本实施例获得的OH^-型阴离子交换膜离子交换容量为1.53mmol/g，室温下离子传导率为3.6×10^-2S·cm^-1，90℃下离子传导率为6.26×10^-2S·cm^-1。抗张强度为10.23Mpa，杨氏模量为521.34Mpa，断裂伸长率为55.34％。

0.20g (0.87mmol), 0.30g (5.60mmol) of acrylonitrile, 0.01g of benzoin ethyl ether, 0.02g of azobisisobutyronitrile, mix the solution evenly, apply it on the mold, polymerize at 75°C for 6 hours, and in situ Polymerize into film. Then soak the anion exchange membrane in 60°C 10M KOH solution to convert anions into OH ^- . The ion exchange capacity of the OH ^- type anion exchange membrane obtained in this example is 1.53mmol/g, and the ion conductivity at room temperature is 3.6×10 ^-2 S·cm ^-1 , the ion conductivity at 90°C is 6.26×10 ^-2 S·cm ^-1 . The tensile strength is 10.23Mpa, the Young's modulus is 521.34Mpa, and the elongation at break is 55.34%.

Embodiment four:

0.20g(0.53mmol)，α-甲基丙烯腈0.2g(2.96mmol)，丙烯腈0.10g(1.87mmol)，安息香乙醚0.01g，二乙烯基苯0.02g，将溶液混合均匀，涂到模具上，γ射线照射10s，原位聚合成膜。然后将该阴离子交换膜浸泡在80℃3M KOH溶液中将阴离子转换成OH^-，本实施例获得的OH^-型阴离子交换膜离子交换容量为0.96mmol/g，室温下离子传导率为1.9×10^-2S·cm^-1，90℃下离子传导率为4.53×10^-2S·cm^-1。抗张强度为13.53Mpa，杨氏模量为671.87Mpa，断裂伸长率为35.24％。

0.20g (0.53mmol), 0.2g (2.96mmol) of α-methacrylonitrile, 0.10g (1.87mmol) of acrylonitrile, 0.01g of benzoin ether, 0.02g of divinylbenzene, mix the solution evenly, and apply it on the mold , γ-ray irradiation for 10s, in situ polymerization film. Then soak the anion exchange membrane in 3M KOH solution at 80°C to convert anions into OH ^- . The ion exchange capacity of the OH ^- type anion exchange membrane obtained in this example is 0.96 mmol/g, and the ion conductivity at room temperature is 1.9×10 ^-2 S·cm ^-1 , the ion conductivity at 90°C is 4.53×10 ^-2 S·cm ^-1 . The tensile strength is 13.53Mpa, the Young's modulus is 671.87Mpa, and the elongation at break is 35.24%.

Embodiment five:

0.20g(0.60mmol)，α-甲基丙烯腈0.10g(1.48mmol)，α-甲基苯乙烯0.1g(0.85mmol)，丙烯腈0.10g(1.87mmol)，安息香乙醚0.01g，二乙烯基苯0.05g，将溶液混合均匀，涂到模具上，紫外光照(波长240nm-380nm)30min，原位聚合成膜。然后将该阴离子交换膜浸泡在60℃7M NaOH溶液中，将阴离子转换成OH^-，本实施例获得的OH^-型阴离子交换膜离子交换容量为1.12mmol/g室温下离子传导率为2.74×10^-2S·cm^-1，90℃下离子传导率为5.13×10^-2S·cm^-1。抗张强度为23.53Mpa，杨氏模量为1271Mpa，断裂伸长率为11.12％。

0.20g (0.60mmol), α-methacrylonitrile 0.10g (1.48mmol), α-methylstyrene 0.1g (0.85mmol), acrylonitrile 0.10g (1.87mmol), benzoin ethyl ether 0.01g, divinyl Benzene 0.05g, mix the solution evenly, apply it on the mold, irradiate with ultraviolet light (wavelength 240nm-380nm) for 30min, and polymerize in situ to form a film. Then soak the anion exchange membrane in 7M NaOH solution at 60°C to convert the anions into OH ^- . The ion exchange capacity of the OH ^- type anion exchange membrane obtained in this example is 1.12 mmol/g and the ion conductivity at room temperature is 2.74×10 ^-2 S·cm ^-1 , the ion conductivity at 90°C is 5.13×10 ^-2 S·cm ^-1 . The tensile strength is 23.53Mpa, the Young's modulus is 1271Mpa, and the elongation at break is 11.12%.

Embodiment six

0.25g(0.76mmol)，丙烯腈0.15g(2.80mmol)，0.01g，二乙烯基苯0.03g，，将溶液混合均匀，涂到模具上，紫外光照(波长240nm-380nm)30min，原位聚合成膜。然后将该阴离子交换膜浸泡在60℃1M KOH溶液中，将阴离子转换成OH^-，本实施例获得的OH^-型阴离子交换膜离子交换容量为1.62mmol/g，室温下离子传导率为3.53×10^-2S·cm^-1，90℃下离子传导率为6.11×10^-2S·cm^-1。抗张强度为11.26Mpa，杨氏模量为571Mpa，断裂伸长率为26.32％。

0.25g (0.76mmol), acrylonitrile 0.15g (2.80mmol), 0.01g, 0.03g of divinylbenzene, mix the solution evenly, apply it on the mold, irradiate with ultraviolet light (wavelength 240nm-380nm) for 30min, and polymerize in situ to form a film. Then soak the anion exchange membrane in 60℃ 1M KOH solution to convert anions into OH ^- . The ion exchange capacity of the OH ^- type anion exchange membrane obtained in this example is 1.62mmol/g, and the ion conductivity at room temperature is 3.53× 10 ^-2 S·cm ^-1 , and the ion conductivity at 90°C is 6.11×10 ^-2 S·cm ^-1 . The tensile strength is 11.26Mpa, the Young's modulus is 571Mpa, and the elongation at break is 26.32%.

Embodiment seven

0.20g(0.85mmol)，苯乙烯0.10g(0.96mmol)，丙烯腈0.2g(3.73mmol)，

0.01g，二乙烯基苯0.02g，将溶液混合均匀，涂到模具上，紫外光照(波长240nm-380nm)30min，原位聚合成膜。然后将该阴离子交换膜浸泡在60℃6M KOH溶液中24小时，将阴离子转换成OH^-，本实施例获得的OH^-型阴离子交换膜离子交换容量为1.48mmol/g室温下离子传导率为3.21×10^-2S·cm^-1，90℃下离子传导率为6.46×10^-2S·cm^-1。抗张强度为11.92Mpa，杨氏模量为433.7Mpa，断裂伸长率为48.65％。

0.20g (0.85mmol), styrene 0.10g (0.96mmol), acrylonitrile 0.2g (3.73mmol),

0.01g, 0.02g of divinylbenzene, mix the solution evenly, apply it on the mold, irradiate with ultraviolet light (wavelength 240nm-380nm) for 30min, and polymerize in situ to form a film. Then soak the anion exchange membrane in 6M KOH solution at 60°C for 24 hours to convert the anions into OH ^- . The ion exchange capacity of the OH ^- type anion exchange membrane obtained in this example is 1.48mmol/g. ×10 ^-2 S·cm ^-1 , and the ion conductivity at 90°C is 6.46×10 ^-2 S·cm ^-1 . The tensile strength is 11.92Mpa, the Young's modulus is 433.7Mpa, and the elongation at break is 48.65%.

Embodiment eight

0.20g(0.71mmol)，苯乙烯0.10g(0.96mmol)，丙烯腈0.20g(3.73mmol)，

0.01g，二乙烯基苯0.02g，将溶液混合均匀，涂到模具上，紫外光照(波长240nm-380nm)30min，原位聚合成膜。然后将该阴离子交换膜浸泡在60℃1M KOH溶液中24小时，将阴离子转换成OH^-，本实施例获得的OH^-型阴离子交换膜离子交换容量为1.39mmol/g，室温下离子传导率为2.75×10^-2S·cm^-1，90℃下离子传导率为5.16×10^-2S·cm^-1。抗张强度为8.98Mpa，杨氏模量为621Mpa，断裂伸长率为33.67％。

0.20g (0.71mmol), styrene 0.10g (0.96mmol), acrylonitrile 0.20g (3.73mmol),

0.01g, divinylbenzene 0.02g, mix the solution evenly, apply it on the mold, irradiate with ultraviolet light (wavelength 240nm-380nm) for 30min, and polymerize in situ to form a film. Then soak the anion exchange membrane in 1M KOH solution at 60°C for 24 hours to convert the anions into OH ^- . The ion exchange capacity of the OH ^- type anion exchange membrane obtained in this example is 1.39 mmol/g, and the ion conductivity at room temperature is 2.75×10 ^-2 S·cm ^-1 , and the ion conductivity at 90°C is 5.16×10 ^-2 S·cm ^-1 . The tensile strength is 8.98Mpa, the Young's modulus is 621Mpa, and the elongation at break is 33.67%.

Embodiment nine:

0.25g(1.07mmol)，α-甲基丙烯腈0.10g(1.48mmol)，α-甲基苯乙烯0.10g(0.85mmol)，安息香乙醚0.01g，二乙烯基苯0.02g，将溶液混合均匀，涂到模具上，紫外光照(波长240nm-380nm)30min，原位聚合成膜。然后将该阴离子交换膜浸泡在60℃1M KOH溶液中24小时，将阴离子转换成OH^-，本实施例获得的OH^-型阴离子交换膜离子交换容量为1.78mmol/g，室温下离子传导率为3.06×10^-2S·cm^-1，90℃下离子传导率为6.53×10^-2S·cm^-1。抗张强度为11.41Mpa，杨氏模量为439.9Mpa，断裂伸长率为52.65％。

0.25g (1.07mmol), α-methacrylonitrile 0.10g (1.48mmol), α-methylstyrene 0.10g (0.85mmol), benzoin ether 0.01g, divinylbenzene 0.02g, mix the solution evenly, Apply to the mold, irradiate with ultraviolet light (wavelength 240nm-380nm) for 30 minutes, and polymerize in situ to form a film. Then soak the anion exchange membrane in 60°C 1M KOH solution for 24 hours to convert the anions into OH ^- . The ion exchange capacity of the OH ^- type anion exchange membrane obtained in this example is 1.78mmol/g, and the ion conductivity at room temperature is 3.06×10 ^-2 S·cm ^-1 , and the ion conductivity at 90°C is 6.53×10 ^-2 S·cm ^-1 . The tensile strength is 11.41Mpa, the Young's modulus is 439.9Mpa, and the elongation at break is 52.65%.

Embodiment ten

0.20g(0.65mmol)，α-甲基丙烯腈0.20g(2.99mmol)，α-甲基苯乙烯0.10g(0.85mmol)，安息香乙醚0.02g，二乙烯基苯0.04g，将溶液混合均匀，涂到模具上，紫外光照(波长240nm-380nm)30min，原位聚合成膜。然后将该阴离子交换膜浸泡在60℃1M KOH溶液中，将阴离子转换成OH^-，本实施例获得的OH^-型阴离子交换膜离子交换容量为1.18mmol/g室温下离子传导率为2.69×10^-2S·cm^-1，90℃下离子传导率为5.28×10^-2S·cm^-1。抗张强度为25.13Mpa，杨氏模量为1041Mpa，断裂伸长率为13.22％

0.20g (0.65mmol), α-methacrylonitrile 0.20g (2.99mmol), α-methylstyrene 0.10g (0.85mmol), benzoin ethyl ether 0.02g, divinylbenzene 0.04g, mix the solution evenly, Apply to the mold, irradiate with ultraviolet light (wavelength 240nm-380nm) for 30 minutes, and polymerize in situ to form a film. Then soak the anion exchange membrane in 60°C 1M KOH solution to convert the anions into OH ^- . The ion exchange capacity of the OH ^- type anion exchange membrane obtained in this example is 1.18mmol/g and the ion conductivity at room temperature is 2.69×10 ^-2 S·cm ^-1 , the ion conductivity at 90°C is 5.28×10 ^-2 S·cm ^-1 . Tensile strength is 25.13Mpa, Young's modulus is 1041Mpa, elongation at break is 13.22%

Embodiment Eleven

Take the anion exchange membrane prepared in the ratio described in example two as sample, carry out the alkali resistance test of the polymer anion exchange membrane of ionic liquid, the alkali resistance performance test of anion exchange membrane is with reference to text (Macromolecules 2010,43,3890-3896) Described method, anion-exchange membrane is soaked in the 1M KOH solution of 60 ℃, takes out membrane at regular intervals, soaks in deionized water to remove residual KOH in the membrane, adopts AC impedance method to measure the ionic conductivity of anion-exchange membrane , the temperature range is 30 ° C ~ 90 ° C. The test results are shown in Figure 1, and the results show that with the increase of soaking time in alkaline solution, the ion conductivity of the anion exchange membrane does not show a downward trend like the traditional anion exchange membrane. Experiments prove that the polymer anion exchange membrane based on ionic liquid prepared by the invention has good alkali resistance.

Claims (5)

1. the preparation method of a basic anion exchange membrane, it is characterized in that, may further comprise the steps: the mixed that with polymer monomer and aggretion type ionic liquid is 1: 2～1: 9 with mol ratio, add linking agent and initiator again, mix mixed solution is ultrasonic, carry out in-situ polymerization and prepare polymer anion-exchange membrane;

Described monomer is selected from one or more the mixture in vinyl cyanide, vinylbenzene, alpha-methyl styrene, the Alpha-Methyl vinyl cyanide;

Described aggretion type ionic liquid is selected from:

In a kind of, m=4～10 wherein, p=0～6, X is selected from: a kind of among I, Br or the Cl.

2. preparation method according to claim 1 is characterized in that, described linking agent is selected from: Vinylstyrene, described linking agent quality are 2%～12% of polymer monomer and aggretion type ionic liquid quality sum.

3. preparation method according to claim 1 is characterized in that initiator is selected from: Benzoin ethyl ether, Diisopropyl azodicarboxylate,

In a kind of; Described initiator quality is 1%～6% of polymer monomer and an aggretion type ionic liquid quality sum.

4. preparation method according to claim 1 is characterized in that, and is further comprising the steps of: the anion-exchange membrane of preparation is immersed in 50～80 ℃ the alkali lye carries out anionresin; Wherein, described ionic liquid is the ionic liquid of aggretion type virtue heterocycle structure; Described alkali lye is the potassium hydroxide of 1～10M or the aqueous solution of sodium hydroxide.

5. adopt that claim 1 or 2 or 3 or 4 described methods prepare based on ion liquid polymer anion-exchange membrane.

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