阅读说明：本技术 一种阴离子交换膜的制备方法 (Preparation method of anion exchange membrane ) 是由 徐铜文 葛亮 纪文根 于 2019-09-04 设计创作，主要内容包括：本发明公开一种阴离子交换膜的制备方法,包括以下步骤：将卤甲基化聚合物溶解于第一有机溶剂中,形成卤甲基化聚合物溶液；向卤甲基化聚合物溶液中加入含有亲水性侧长链的叔胺单体A进行第一次季铵化反应,得到含有亲水性侧长链的季铵化聚合物Ⅰ；将季铵化聚合物Ⅰ溶解于第二有机溶剂中,形成季铵化聚合物Ⅰ溶液；向季铵化聚合物Ⅰ溶液中加入含有双键的叔胺单体B进行第二次季铵化反应,得到同时含有亲水性侧长链和双键的季铵化聚合物Ⅱ；将季铵化聚合物Ⅱ溶解制成铸膜液,然后成型为薄膜,制得阴离子交换膜。本发明通过同时引入亲水性侧长链和双键基团,使得制备的阴离子交换膜同时具有较高的H<Sup>+</Sup>离子渗析系数与分离因子。(the invention discloses a preparation method of an anion exchange membrane, which comprises the following steps: dissolving a halomethylated polymer in a first organic solvent to form a halomethylated polymer solution; adding a tertiary amine monomer A containing a hydrophilic side long chain into a halomethylated polymer solution to carry out a first quaternization reaction to obtain a quaternization polymer I containing the hydrophilic side long chain; dissolving a quaternary ammonium polymer I in a second organic solvent to form a quaternary ammonium polymer I solution; adding a tertiary amine monomer B containing double bonds into the quaternized polymer I solution to carry out a second quaternization reaction to obtain a quaternized polymer II containing hydrophilic side long chains and double bonds; and dissolving the quaternary ammonium polymer II to prepare a membrane casting solution, and then forming the membrane into a thin film to prepare the anion exchange membrane. According to the invention, the hydrophilic side long chain and the double bond group are introduced simultaneously, so that the prepared anion exchange membrane has higher H + The electrodialysis coefficient and the separation factor.)

1. A preparation method of an anion exchange membrane is characterized by comprising the following steps:

Dissolving a halomethylated polymer in a first organic solvent to form a halomethylated polymer solution;

adding a tertiary amine monomer A containing a hydrophilic side long chain into the halomethylated polymer solution to carry out a first quaternization reaction to obtain a quaternization polymer I containing the hydrophilic side long chain;

Dissolving the quaternary ammonium polymer I in a second organic solvent to form a quaternary ammonium polymer I solution;

adding a tertiary amine monomer B containing double bonds into the quaternized polymer I solution to carry out a second quaternization reaction to obtain a quaternized polymer II containing hydrophilic side long chains and double bonds;

And dissolving the quaternary ammonium polymer II to prepare a membrane casting solution, and then forming into a thin membrane to prepare the anion exchange membrane.

2. The method of claim 1, wherein the halomethylated polymer comprises any one of polyphenylene oxide, polyether sulfone and polyether ketone containing halomethyl groups, wherein the halomethyl groups comprise any one of chloromethyl, bromomethyl and iodomethyl groups.

3. The method of preparing an anion exchange membrane according to claim 2, wherein the halomethylated polymer is brominated polyphenylene ether, and the bromination degree of the brominated polyphenylene ether is 30 to 100%.

4. The method of claim 1 wherein said hydrophilic pendant long chain containing tertiary amine monomer a comprises tris (3, 6-dioxaheptyl) amine or methyltriethanolamine.

5. The method of claim 1 wherein said double bond containing tertiary amine monomer B comprises dimethylaminoethyl methacrylate or N-4-vinylphenyl-N, N-dimethylamine.

6. The method of preparing an anion exchange membrane according to claim 1, wherein the step of dissolving the halomethylated polymer in a first organic solvent to form a halomethylated polymer solution comprises:

The mass concentration of the halomethylated polymer in the halomethylated polymer solution is 5-15%; and/or the presence of a gas in the gas,

The first organic solvent comprises any one of N-methyl pyrrolidone, dimethyl sulfoxide and N, N-dimethylformamide.

7. the method for producing an anion-exchange membrane according to claim 1, wherein the step of adding a tertiary amine monomer a containing a hydrophilic side long chain to the halomethylated polymer solution to perform a first quaternization reaction to obtain a quaternized polymer i containing a hydrophilic side long chain comprises:

The halomethylated polymer is brominated polyphenylene ether (BPPO), and the addition mass Y of the tertiary amine monomer A is calculated according to the following formula (1):

In the formula (1), x is the addition amount of BPPO, M_BPPOFor the molecular weight of BPPO, n (Br) is the degree of bromination of BPPO, n (D) is the molar fraction of benzyl bromide groups reacted off, M_TAIs the molecular weight of the tertiary amine monomer A, wherein, n (D) is more than 0 percent and less than 100 percent; and/or the presence of a gas in the gas,

The reaction temperature of the first quaternization reaction is 40-100 ℃, and the reaction time is 12-50 h.

8. the method of preparing an anion exchange membrane according to claim 1, wherein the step of dissolving the quaternary ammonium polymer i in a second organic solvent to form a solution of quaternary ammonium polymer i comprises:

The mass concentration of the quaternary ammonium polymer I in the quaternary ammonium polymer I solution is 5-15%; and/or the presence of a gas in the gas,

The second organic solvent comprises any one of N-methyl pyrrolidone, dimethyl sulfoxide and N, N-dimethylformamide.

9. the method for preparing an anion-exchange membrane according to claim 1, wherein the step of adding a tertiary amine monomer B containing double bonds into the quaternary polymer I solution to carry out a second quaternization reaction to obtain a quaternary polymer II containing both hydrophilic side long chains and double bonds is as follows:

The reaction temperature of the second quaternization reaction is 10-30 ℃, and the reaction time is 12-50 h.

10. The method for preparing an anion exchange membrane according to claim 1, wherein the step of dissolving the quaternary ammonium polymer II to prepare a membrane casting solution, and then forming the membrane into a thin membrane to prepare the anion exchange membrane comprises:

Dissolving the quaternary ammonium polymer II in a third solvent to prepare a membrane casting solution, coating the membrane casting solution, and drying and forming the membrane casting solution into a thin film to prepare the anion exchange membrane;

Wherein the third solvent comprises any one of N-methyl pyrrolidone, dimethyl sulfoxide and N, N-dimethylformamide, and/or,

The drying temperature during drying and molding is 60-100 ℃, and the drying time is 8-30 h.

Technical Field

the invention relates to the technical field of anion exchange membranes, in particular to a preparation method of an anion exchange membrane.

Background

The development of industry in recent years has created a great threat to the environment, one of the biggest problems being the discharge of large quantities of acid waste liquid, which is remarkable in quantity and involves many fieldssuch as steel pickling waste acid liquid, titanium dioxide waste acid liquid, metallurgical waste acid liquid, metal electrolysis waste liquid, fine chemical production waste liquid and the like. These acidic waste liquids contain H₂SO₄、HNO₃、HCl、HCN、H₃PO₄Or the mixture thereof has great harm to the environment, generally, about 55-75 kg of pickling waste liquid is generated in each ton of steel production, in addition, 20-50 times of pickling waste water is generated, and according to statistics of relevant departments, the amount of waste (acid) water generated by key steel enterprises in China per year is 30 billion cubic meters. The traditional treatment method can not meet the development requirements of related industries and is not in line with the time characteristics of energy conservation, emission reduction and consumption reduction of the whole society. Therefore, the treatment of the waste liquid is urgent, the core of the treatment is to realize the recycling of acid and inorganic salt, and the precondition for achieving the purpose is to realize the effective separation of acid and metal ions.

Diffusion dialysis, as a membrane separation technique using concentration difference as a driving force, has incomparable advantages with other membrane separation processes at present with increasingly severe environmental pollution and energy shortage due to the advantages of low energy consumption, simple operation, environment-friendly process and the like. Currently, diffusion dialysis processes based on anion exchange membranes are widely used in the waste acid recovery industry. The anion exchange membrane, which is the core component of the diffusion dialysis acid recovery process, directly determines the recovery efficiency of the acid in the whole process. However, the anion exchange membranes for diffusion dialysis currently commercialized mostly have the problems of low acid recovery efficiency, low metal ion retention rate and the like, so that the development of anion exchange membranes with high acid recovery rate and high selectivity is a problem which needs to be overcome at present to further expand the application range of the diffusion dialysis process in the field of acid recovery.

Disclosure of Invention

The invention mainly aims to provide a preparation method of an anion exchange membrane, aiming at ensuring that the anion exchange membrane has higher H simultaneously⁺the electrodialysis coefficient and the separation factor.

in order to achieve the above purpose, the invention provides a preparation method of an anion exchange membrane, which comprises the following steps:

Dissolving a halomethylated polymer in a first organic solvent to form a halomethylated polymer solution;

Adding a tertiary amine monomer A containing a hydrophilic side long chain into the halomethylated polymer solution to carry out a first quaternization reaction to obtain a quaternization polymer I containing the hydrophilic side long chain;

dissolving the quaternary ammonium polymer I in a second organic solvent to form a quaternary ammonium polymer I solution;

Adding a tertiary amine monomer B containing double bonds into the quaternized polymer I solution to carry out a second quaternization reaction to obtain a quaternized polymer II containing hydrophilic side long chains and double bonds;

And dissolving the quaternary ammonium polymer II to prepare a membrane casting solution, and then forming into a thin membrane to prepare the anion exchange membrane.

Optionally, the halomethylated polymer comprises any one of polyphenylene oxide, polyether sulfone and polyether ketone containing halomethyl, wherein the halomethyl comprises any one of chloromethyl, bromomethyl and iodomethyl.

Optionally, the halomethylated polymer is brominated polyphenylene ether, and the bromination degree of the brominated polyphenylene ether is 30-100%.

Alternatively, the hydrophilic side long chain containing tertiary amine monomer A comprises tris (3, 6-dioxaheptyl) amine or methyltriethanolamine.

Alternatively, the double bond-containing tertiary amine monomer B comprises dimethylaminoethyl methacrylate or N-4-vinylphenyl-N, N-dimethylamine.

optionally, in the step of dissolving the halomethylated polymer in a first organic solvent to form a halomethylated polymer solution:

The mass concentration of the halomethylated polymer in the halomethylated polymer solution is 5-15%; and/or the presence of a gas in the gas,

The first organic solvent comprises any one of N-methyl pyrrolidone, dimethyl sulfoxide and N, N-dimethylformamide.

Optionally, in the step of adding a tertiary amine monomer A containing a hydrophilic side long chain into the halomethylated polymer solution to perform a first quaternization reaction to obtain a quaternized polymer I containing a hydrophilic side long chain:

the halomethylated polymer is brominated polyphenylene ether (BPPO), and the addition mass Y of the tertiary amine monomer A is calculated according to the following formula (1):

In the formula (1), x is the addition amount of BPPO, M_BPPOIs the molecular weight of BPPO, n (Br) is the degree of bromination of BPPO, n (D) isMolar fraction of benzyl bromide groups reacted off, M_TAIs the molecular weight of the tertiary amine monomer A, wherein, n (D) is more than 0 percent and less than 100 percent; and/or the presence of a gas in the gas,

The reaction temperature of the first quaternization reaction is 40-100 ℃, and the reaction time is 12-50 h.

Optionally, in the step of dissolving the quaternized polymer I in a second organic solvent to form a quaternized polymer I solution:

The mass concentration of the quaternary ammonium polymer I in the quaternary ammonium polymer I solution is 5-15%; and/or the presence of a gas in the gas,

the second organic solvent comprises any one of N-methyl pyrrolidone, dimethyl sulfoxide and N, N-dimethylformamide.

Optionally, in the step of adding a tertiary amine monomer B containing double bonds into the quaternized polymer I solution to carry out a second quaternization reaction to obtain a quaternized polymer II containing both hydrophilic side long chains and double bonds:

the reaction temperature of the second quaternization reaction is 10-30 ℃, and the reaction time is 12-50 h.

Optionally, the step of dissolving the quaternary ammonium polymer II to prepare a membrane casting solution, and then forming the membrane into a thin membrane to prepare the anion exchange membrane comprises the following steps:

Dissolving the quaternary ammonium polymer II in a third solvent to prepare a membrane casting solution, coating the membrane casting solution, and drying and forming the membrane casting solution into a thin film to prepare the anion exchange membrane;

wherein the third solvent comprises any one of N-methyl pyrrolidone, dimethyl sulfoxide and N, N-dimethylformamide, and/or,

The drying temperature during drying and molding is 60-100 ℃, and the drying time is 8-30 h.

According to the technical scheme provided by the invention, a tertiary amine monomer A containing a hydrophilic side long chain and a tertiary amine monomer B containing a double bond are selected for preparing a quaternized polymer containing both the hydrophilic side long chain and the double bond and preparing an anion exchange membrane, and the hydrophilic side long chain is introduced through quaternization reaction to regulate and control the hydrophilicity and hydrophobicity of the membraneThe method comprises the steps of preparing water and a microstructure of a membrane, introducing double bonds through quaternization, further regulating and controlling the microstructure of the membrane, simultaneously regulating and controlling the density of the membrane through the thermal crosslinking reaction of the double bonds in the membrane preparation process, and finally realizing higher H based on pore size screening and the hydrophilicity of side long chains⁺The ion dialysis coefficient and the separation factor have better acid recovery performance when used as an anion exchange membrane for acid recovery.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other related drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic flow diagram of one embodiment of a method for preparing an anion exchange membrane provided by the present invention;

Fig. 2 is an in situ infrared spectrum of the anion exchange membrane prepared in example 3 (C ═ C functional groups);

figure 3 is an in situ infrared spectrum of the anion exchange membrane prepared in example 3 (C ═ C-H functionality);

FIG. 4 is an in situ infrared spectrum (C-H functionality) of the anion exchange membrane prepared in example 3;

FIG. 5 is a comparison of the state of the membrane casting solution used for preparing the anion exchange membrane in example 3 and comparative example 1 before and after heating;

FIG. 6 is an in situ infrared spectrum (C-O-C functional groups) of the anion exchange membrane prepared in comparative example 1;

FIG. 7 is an atomic force microscope image of an anion exchange membrane prepared in comparative example 1;

FIG. 8 is an atomic force microscope image of the anion exchange membrane prepared in example 3.

The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

Detailed Description

in order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially. In addition, the meaning of "and/or" appearing throughout includes three juxtapositions, exemplified by "A and/or B" including either A or B or both A and B. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention provides a preparation method of an anion exchange membrane, which is simple and convenient for large-scale industrial production, and the prepared anion exchange membrane has higher H⁺FIG. 1 shows an example of the preparation method of the anion exchange membrane provided by the present invention. Referring to fig. 1, in the present embodiment, the method for preparing an anion exchange membrane includes the following steps:

step S10, dissolving a halomethylated polymer in a first organic solvent to form a halomethylated polymer solution;

The halomethylated polymer can be any one of polyphenyl ether, polyether sulfone and polyether ketone containing halomethyl, wherein the halomethyl comprises any one of chloromethyl, bromomethyl and iodomethyl, more preferably chloromethyl or bromomethyl, and specifically, polymers such as chlorinated polyphenyl ether, brominated polyphenyl ether, chlorinated polyether sulfone, brominated polyether sulfone, chlorinated polyether ketone or brominated polyether ketone can be selected. In the present embodiment, the halomethylated polymer is more preferably brominated polyphenylene ether (in the following embodiments, the halomethylated polymer is brominated polyphenylene ether BPPO, for example), and the bromination degree of the BPPO is 30-100%.

The first organic solvent is used for dissolving the halomethylated polymer, and may specifically be a common organic solvent such as N-methylpyrrolidone, dimethylsulfoxide, N-dimethylformamide, and the like, in this embodiment, N-methylpyrrolidone (NMP) is preferably used, and when the halomethylated polymer solution is prepared, a halomethylated polymer solution with a mass concentration of 5 to 15% is preferably prepared, and in this mass concentration range, the halomethylated polymer can be quickly dissolved in NMP to form a uniform polymer solution.

Step S20, adding a tertiary amine monomer A containing a hydrophilic side long chain into the halomethylated polymer solution to carry out a first quaternization reaction to obtain a quaternization polymer I containing the hydrophilic side long chain;

The tertiary amine monomer A containing the hydrophilic side long chain has the function of consuming part of halomethyl groups in the halomethylated polymer by quaternization after being added into the halomethylated polymer solution, and for example, tris (3, 6-dioxaheptyl) amine, methyltriethanolamine and the like are selected, tris (3, 6-dioxaheptyl) amine (TDA) is preferred in the embodiment, and correspondingly, the reaction process of step S20 is as follows: the TDA, after addition to the BPPO solution, consumes a portion of the benzyl bromide groups in the BPPO by quaternization. Further, the specific addition mass (g) of the tertiary amine monomer a may be calculated according to the following formula:

Wherein x is the added mass of BPPO, g; m_BPPOIs the molecular weight of BPPO; n (Br) is the degree of bromination of BPPO; n (D) is the mole fraction of benzyl bromide groups reacted off,%; m_TAIs the molecular weight of tertiary amine monomer a; wherein 0% < n (D) < 100%. That is, the tertiary amine monomer A, when added, is based on the benzyl bromide groups consumed by reaction when the first quaternization reaction occursThe molar amount of the tertiary amine monomer a is calculated based on the molar amount of the benzyl bromide group consumed in the reaction, and when the first quaternization reaction is performed, for example, the amount of the tertiary amine monomer a added is 1 to 99% of the molar amount of the benzyl bromide group consumed in the reaction in the BPPO, preferably 30 to 70% of the molar amount of the benzyl bromide group consumed in the reaction, and more preferably 40 to 60% of the molar amount of the benzyl bromide group consumed in the reaction.

Furthermore, the TDA is added in a manner of slowly dripping into the BPPO solution during addition, then stirring and reacting for 12-50 h at the temperature of 40-100 ℃, after the reaction is finished, slowly dripping the obtained reaction solution into anhydrous ether for purification, performing suction filtration by using a Buchner funnel, washing the product after the suction filtration by using ether for a plurality of times, and drying to obtain the quaternized polymer I containing the hydrophilic side long chain.

Step S30, dissolving the quaternary ammonium polymer I in a second organic solvent to form a quaternary ammonium polymer I solution;

similarly, the second organic solvent is used to dissolve the halomethylated polymer, and specifically, a common organic solvent such as N-methylpyrrolidone (NMP), dimethylsulfoxide, N-dimethylformamide and the like can be selected, in this embodiment, NMP is preferably used, and in the solution of the quaternized polymer i formed by dissolving, the mass concentration of the solution of the quaternized polymer i is preferably 5 to 15%, which is beneficial to rapidly dissolving the quaternized polymer i.

Step S40, adding a tertiary amine monomer B containing double bonds into the quaternary ammonium polymer I solution to carry out a second quaternary ammonium reaction to obtain a quaternary ammonium polymer II containing both hydrophilic side long chains and double bonds;

The tertiary amine monomer B containing a double bond is used for quaternization to consume the remaining halomethyl group in the halomethylated polymer after being added to the solution of the quaternized polymer i, and may be a tertiary amine monomer containing a double bond, such as dimethylaminoethyl methacrylate, N-4-vinylphenyl-N, N-dimethylamine, etc., preferably dimethylaminoethyl methacrylate (DMAEMA), and correspondingly, the reaction process of step S40 is: the DMAEMA, after addition to the quaternized polymer i solution, consumes the remaining benzyl bromide groups in the BPPO by quaternization. The tertiary amine monomer B may be added to consume all of the remaining benzyl bromide groups in the BPPO, or may be added to consume only a part of the remaining benzyl bromide groups, for example, when 55 mol% of the remaining benzyl bromide groups in the BPPO are consumed in the first quaternization, the remaining 45 mol% of the remaining benzyl bromide groups may be consumed in the second quaternization, or may be added to consume only a part of the remaining 45 mol% of the remaining benzyl bromide groups, for example, 15%, 20%, or 30%, and the like, and the object of the present invention to prepare a quaternized polymer containing both hydrophilic side long chains and double bond groups can be achieved.

further, when the DMAEMA is added, the DMAEMA is slowly added into the solution of the quaternary polymer I in a dropwise manner, then the mixture is stirred and reacts for 12-50 hours at the temperature of 10-30 ℃, after the reaction is finished, the obtained reaction solution is slowly added into anhydrous ether in a dropwise manner for purification, the extraction and filtration are carried out by using a Buchner funnel, and the product after the extraction and filtration is washed by ether for a plurality of times and then dried at room temperature, so that the quaternary polymer II containing the hydrophilic side long chain and the double bond group is obtained.

And step S50, dissolving the quaternary ammonium polymer II to prepare a membrane casting solution, and then forming the membrane into a thin film to prepare the anion exchange membrane.

There are various ways of forming the quaternary ammonium polymer ii into a casting solution and then forming the casting solution into a film, such as coating, scraping, casting, etc., in this embodiment, the method of coating is taken as an example, and the step S50 can be performed as follows: dissolving the quaternary ammonium polymer II in a third solvent to prepare a membrane casting solution, coating the membrane casting solution, and drying and forming the membrane casting solution into a thin film to prepare the anion exchange membrane; the third solvent may be a common solvent such as N-methylpyrrolidone (NMP), dimethylsulfoxide, and N, N-dimethylformamide, and preferably NMP. Further, the casting solution may be coated on a glass plate or the like as a coating substrate, and after the coating is completed, the solvent is removed by heating and drying, and then the coating substrate is peeled off, so as to obtain the anion-exchange membrane, wherein the drying conditions of heating and drying are preferably 60 to 100 ℃ and 8 to 30 hours.

The invention starts from the design of polymer molecular chains and the regulation and control of the microstructure of the polymer film, and the preparation has higher H simultaneously⁺An anion exchange membrane of an ion dialysis coefficient and a separation factor. The method is characterized in that a tertiary amine monomer containing a hydrophilic side long chain and a tertiary amine monomer containing a double bond are selected to prepare a quaternized polymer containing the hydrophilic side long chain and the double bond simultaneously, and the quaternized polymer is used for preparing an anion exchange membrane. The hydrophilic and hydrophobic properties of the membrane and the microstructure of the membrane are regulated by introducing hydrophilic side long chains through quaternization, the side long chains containing double bonds are further introduced through quaternization to further regulate the microstructure of the membrane, meanwhile, the thermal crosslinking reaction of the double bonds is generated in the membrane preparation process to regulate the density of the membrane, and finally, the higher H is realized based on pore size screening and the hydrophilicity of the side long chains⁺The ion dialysis coefficient and the separation factor have better acid recovery performance when used as an anion exchange membrane for acid recovery.

Specifically, hydrophilic side long chains are introduced through quaternization to regulate the hydrophilicity and hydrophobicity of the membrane and the microstructure of the membrane. Because the main chain of the halomethylated polymer is hydrophobic, and the introduced side chain is a hydrophilic side long chain, based on the difference of hydrophilicity and hydrophobicity, the molecular chain of the quaternized polymer I containing the hydrophilic side long chain generates a molecular self-assembly behavior, so that a nano-scale hydrophilic area aggregation area which is favorable for ion transmission, namely an ion transmission channel, is formed. The formation of this microstructure ensures that the produced film has a higher H⁺the coefficient of ion dialysis. In particular, a large number of hydrophilic groups (hydrophilic side chains) are contained in the aggregation region, and the design will further increase the H of the prepared membrane⁺The coefficient of ion dialysis. The introduction of the double bond group is to generate thermal crosslinking reaction in the film preparation process, improve the density of the film and further improve the microphase separation phenomenon of the film. In the process of crosslinking reaction, the molecular chain of the quaternary ammonium polymer I moves and rearranges further, so that the membrane obtains a more regular microphase separation structure, and the size of a hydrophilic region accumulation region is forced to be further reducedSmall, thereby forming a more compact membrane structure, and finally further improving the separation factor of the membrane. In particular, unlike the addition of a crosslinking agent to improve the density of the film, the double bond groups are introduced by quaternization in the present invention, i.e., the introduction of one double bond group is necessarily accompanied by the generation of one quaternary ammonium group. The traditional cross-linking method can obviously improve the separation performance of the membrane, but always brings H of the membrane⁺The electrodialysis coefficient is significantly reduced. In the present invention, H of the membrane due to thermal crosslinking reaction⁺The reduction of the electrodialysis coefficient can be exactly compensated by the quaternary ammonium groups generated synchronously, thereby finally ensuring that the prepared anion exchange membrane has higher H⁺The electrodialysis coefficient and the separation factor. In addition, the preparation method of the anion exchange membrane provided by the invention also has the advantages of simple membrane preparation process and strong controllability, and has an application prospect of large-scale industrial production.

The technical solutions of the present invention are further described in detail below with reference to specific examples and drawings, it should be understood that the following examples are merely illustrative of the present invention and are not intended to limit the present invention.