CN119751871B

CN119751871B - A polyazine sulfide anion exchange membrane, its preparation method and application

Info

Publication number: CN119751871B
Application number: CN202411902018.0A
Authority: CN
Inventors: 庄小东; 柯长春; 刘萍
Original assignee: Shanghai Jiao Tong University
Current assignee: Shanghai Jiao Tong University
Priority date: 2024-12-23
Filing date: 2024-12-23
Publication date: 2025-11-25
Anticipated expiration: 2044-12-23
Also published as: CN119751871A

Abstract

This application discloses a method for preparing polyazine sulfide and its application, relating to the field of membrane technology. The method includes: preparing a polyazine sulfide polymer; and preparing a polyazine sulfide anion exchange membrane. Thus, an alkaline anion exchange membrane is prepared through polymerization and quaternization. The strong dipole moment azulene groups and sulfur-containing backbone promote the formation of a strengthened hydrogen bond network, facilitating high-speed ^OH- transport. The branched structure generates high mechanical strength, significantly reducing the water absorption and swelling rate of the anion exchange membrane, thereby improving dimensional stability. Simultaneously, the highly stable cationic groups and nucleophilic azulene groups increase its alkaline stability. Its high ^OH- conductivity, alkaline stability, and high mechanical strength indicate that the polyazine sulfide anion exchange membrane prepared in this application can be used as an anion exchange membrane material for alkaline fuel cells and alkaline electrolyzers.

Description

Poly azulene thioether anion exchange membrane and preparation method and application thereof

Technical Field

The application relates to the technical field of membranes, in particular to a polyazulene sulfide anion exchange membrane, a preparation method and application thereof.

Background

Worldwide energy demand continues to grow rapidly due to global evolution and population growth. Green hydrogen can be produced by the electrolysis water technology driven by surplus energy production 'waste light-waste wind power', and the fuel cell is the main application direction of hydrogen energy. At present, a proton exchange membrane fuel cell and an acid electrolytic cell which operate under an acid condition need to use a noble metal catalyst and an expensive proton exchange membrane, so that the cost for preparing hydrogen and utilizing the hydrogen is high, and the industrialized development is greatly hindered. Anion exchange membrane fuel cells and alkaline water electrolysis technology have received great attention because of the availability of low alkaline electrolytes, non-noble metal catalysts, and the significant reduction in operating costs.

Anion Exchange Membranes (AEMs) are key components of anion exchange membrane fuel cells and alkaline cells, and it is important to prepare Gao Qingyang anion exchange membranes with stable conductivity and chemical properties, so as to achieve high power density and long-term durability of the anion exchange membrane fuel cells and alkaline cells. AEM consists of a polymer backbone, cationic groups and mobile ions. The nature of the polymer backbone structure and the cationic groups directly determine the performance of the AEM. Because the radius of OH ^- is larger than that of H ⁺, the conductivity of OH ^- in AEM is only 20% -33% of that of H ⁺ in a proton exchange membrane under the same condition, however, the most direct mode of improving the conductivity is to improve the Ion Exchange Capacity (IEC), and the improvement of IEC means that more hydrophilic cationic groups need to be introduced, which leads to the increase of the water absorption rate of the membrane and the increase of swelling, so that the mechanical property of the membrane is reduced. The "trade-off" effect to address the ionic conductivity and dimensional stability of the membrane is therefore critical to the development of AEM. (2) Under the hot alkali working condition, the polymer skeleton and the cationic groups are easy to attack by nucleophilic OH ^-, so that complex degradation reaction of the main chain structure and the cationic groups occurs, thereby reducing the film performance and even reducing the service life of AEM.

Therefore, improving the alkali stability of AEM and extending the membrane lifetime is an urgent issue to be addressed.

Disclosure of Invention

In order to solve the technical problems in the prior art, the application provides a polyazulene sulfide anion exchange membrane and a preparation method and application thereof, and aims to solve the problems of low AEM ion conductivity, poor alkali stability and the like in the prior art.

In order to achieve the above object, the technical solution of the embodiment of the present application is:

in a first aspect, the present application provides a polyazulene sulfide anion exchange membrane, which contains a polyazulene sulfide polymer and has the following structure:

Wherein R ₁ is a cationic group, R ₂ is a branched group, a is any integer between 1 and 10000, and b is any integer between 0 and 10000.

With reference to the first aspect, preferably, the R ₁ is at least one of the following structures:

Wherein n is an integer of 0 or more.

With reference to the first aspect, preferably, R ₂ is at least one of the following structures (according to the number of its connection bonds, which is one-to-one matched with R ₂ in the above general formula):

in a second aspect, the present application provides a process for preparing the polyazulene sulfide anion exchange membrane according to the first aspect, the process comprising:

(1) Preparation of the polyazulene sulfide polymer:

Placing Na ₂ S, azulene-based monomer A shown in a formula 1 and branched monomer R ₂ -Br into a reaction kettle, dissolving in a first organic solvent, quickly heating, washing and drying a solid product after reaction, and collecting the solid product;

(2) Preparation of polyazulene sulfide anion exchange membranes:

And dissolving the azulene thioether polymer in a second organic solvent, drying, collecting an I ^- type film, carrying out ion exchange on the I ^- type film to obtain an OH ^- type film, and collecting the azulene thioether anion exchange film after purification treatment.

With reference to the second aspect, preferably, the molar ratio of the sum of the addition amounts of the azulene-based monomer and the branching monomer to the addition amount of Na ₂ S is 1:0.9-1.5.

With the second aspect, preferably, the reaction temperature is greater than 150 ℃ and the reaction time is greater than 4 hours.

With reference to the second aspect, preferably, the first organic solvent is one or more of dimethyl sulfoxide, N-methylpyrrolidone and N, N-dimethylformamide.

With reference to the second aspect, preferably, the second organic solvent is one or more of acetonitrile, tetrahydrofuran, N-methylpyrrolidone, dimethyl sulfoxide, N-dimethylacetamide, N-dimethylformamide, N-methylpyrrolidone and sulfolane.

In a third aspect, the application provides a polyazulene sulfide anion exchange membrane as described in the first aspect and the use of the polyazulene sulfide anion exchange membrane prepared by the method as described in the second aspect for preparing alkaline fuel cells and alkaline electrolytic cells.

Compared with the prior art, the embodiment of the application has the advantages or beneficial effects that at least the advantages or beneficial effects comprise:

The azulene thioether anion exchange membrane provided by the embodiment of the application is prepared by polymerization and quaternization, wherein strong dipole moment azulene groups and a sulfur-containing main chain promote the formation of a reinforced hydrogen bond network and promote high-speed transmission of OH ^-, a branched structure generates high mechanical strength, the water absorption and swelling rate of the anion exchange membrane are greatly reduced, so that the dimensional stability is improved, and meanwhile, high-stability cationic groups and nucleophilic azulene groups increase the alkaline stability, and the high OH _- conductivity, the alkaline stability and the high mechanical strength of the membrane indicate that the azulene thioether anion exchange membrane prepared by the application can be used as an anion exchange membrane material for alkaline fuel cells and alkaline electrolytic cells.

The azulene thioether anion exchange membrane provided by the application has high OH ^- conductivity (OH _- conductivity >100mS cm ^-1 at 80 ℃), high mechanical strength (tensile strength >35MPa, elongation at break > 10%), high dimensional stability, good processability and excellent alkaline stability (> 500 h) in 1M KOH at 80 ℃.

Compared with other types of branched poly (aryl-piperidine) anion exchange membranes, the strong dipole moment azulenyl group and the sulfur-containing main chain in the molecular structure promote the formation of a reinforced hydrogen bond network, promote the high-speed transmission of OH ^-, lead the structure to be not easy to be attacked by OH ^- by introducing nucleophilic azulenyl group, enhance the alkaline stability of the structure, lead the molecular chains to be mutually entangled by forming a branched structure, and enhance the mechanical property of the structure.

Drawings

FIG. 1 is a diagram showing the synthetic route of 6-6' -biaazulene crosslinked poly 6-piperidineazulene thioether (b-PAS-6 Pip-BiAz)

FIG. 2 is a diagram showing a synthetic route of b-PAS-6pip-3AzPh according to the present application.

FIG. 3 is a synthetic route diagram of poly (6-piperidyl) azulene thioether (PAS-6 pip) provided by the application.

FIG. 4 is the results of the OH ^- conductivity test of the azulene thioether anion exchange membranes prepared in examples 1,2 and 3.

Fig. 5 is the results of the water electrolysis test of the anion exchange membrane of the polyazulene sulfide anion exchange membranes prepared in examples 1,2 and 3.

Detailed Description

The present application will be further described in detail with reference to the accompanying drawings, for the purpose of making the objects, technical solutions and advantages of the present application more apparent, and the described embodiments should not be construed as limiting the present application, and all other embodiments obtained by those skilled in the art without making any inventive effort are within the scope of the present application.

In the following description, reference is made to "some embodiments" which describe a subset of all possible embodiments, but it is to be understood that "some embodiments" can be the same subset or different subsets of all possible embodiments and can be combined with one another without conflict. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which embodiments of this application belong. The terminology used in the embodiments of the application is for the purpose of describing embodiments of the application only and is not intended to be limiting of the application.

In the following description of the present embodiment, the terms "include," "comprise," "have," "contain," and the like are open-ended terms, meaning including, but not limited to.

It should be noted that all raw materials/reagents in the embodiments of the present application may be purchased on the market or prepared according to conventional methods well known to those skilled in the art, and the term "and/or" in the embodiments of the present application is only used to describe the association relationship of the associated objects, and indicates that three relationships may exist, for example, a and/or B indicates that a exists alone, B exists alone, and a and B exist together, where A, B may be singular or plural, and the character "/" generally indicates that the associated objects are in a "or" relationship.

In the following description of the present embodiments, the term "at least one" means one or more, and "a plurality" means two or more. "at least one of" or the like means any combination of these items, including any combination of single item(s) or plural items(s). For example, "at least one (a), b or c," or "at least one (a), b and c," may each represent a, b, c, a-b (i.e., a and b), a-c, b-c, or a-b-c, wherein a, b, c may each be single or plural.

It should be understood by those skilled in the art that, in the following description of the present embodiment, the sequence number does not mean that the execution sequence is sequential, and some or all of the steps may be executed in parallel or sequentially, and the execution sequence of each process should be determined by its functions and inherent logic, and should not constitute any limitation on the implementation process of the embodiment of the present application.

The terminology used in the embodiments of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this application and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It will be appreciated by those skilled in the art that the numerical ranges in the embodiments of the present application are to be understood as also specifically disclosing each intermediate value between the upper and lower limits of the range. Every smaller range between any Chen Shuzhi and any stated range, and any other stated or intervening values in that stated range, is encompassed within the application. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

Unless otherwise defined, technical/scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the embodiments or testing examples of the present application. All documents referred to in this specification are generally incorporated by reference herein to disclose and describe the methods and/or materials in connection with which the documents are referred to. In case of conflict with any incorporated document, the present specification will control.

It should be noted that all the raw materials and/or reagents in the examples of the present application are commercially available or prepared according to conventional methods well known to those skilled in the art.

The test methods used in the examples are as follows:

Performance test:

The device and the testing method related to the embodiment comprise the following steps:

Ion Exchange Capacity (IEC) test method taking Cl ^- type or Br ^- type film of the azulene thioether polymer, drying in a vacuum oven at 75 ℃ and weighing the mass, and recording dry film weight. The dry film was soaked in 25mL of 0.2M NaNO ₃ solution for 6 hours, repeated three times, and the ion-exchanged NaNO ₃ solution was collected. To this solution was added a solution of indicator potassium chromate and titrated with 0.01M AgNO ₃ standard solution, which when a brick red precipitate appeared and did not disappear after shaking, representing the completion of the titration. The volume of AgNO ₃ solution consumed was recorded. Dividing the product of the concentration and the volume of the AgNO ₃ solution by the mass of the dry film to obtain IEC.

OH ^- conductivity test the electrochemical workstation used was CHI660E, model number of Shanghai Chen Hua instruments Co. The films were tested for conductivity at different temperatures using alternating current impedance (EIS). The potential amplitude measured was 10mV. To reduce the error in the measurement caused by contact resistance, the resistance tested was the transverse (in-plane) resistance of the film sample. In the experiment, the film is cut into the size of 40mm multiplied by 10mm, the film is placed in a clamp, the clamp is placed in pure water, the test temperature is from 30 ℃ to 80 ℃, the film resistance is tested at intervals of 10 ℃, and heat preservation is needed for 1h before the test. Finally, the ionic conductivity σ of the sample was calculated according to the formula σ=l/(wdR), where l is the length (cm) of the inter-electrode membrane, w is the width (cm) of the membrane, d is the thickness (μm) of the membrane, and R is the measured membrane resistance (mΩ).

The electrolytic water performance test of the anion exchange membrane comprises that an anode is titanium felt loaded with IrO ₂(1mg/cm²), a cathode is carbon paper loaded with 10wt% Pt/C (1 mg/cm ²), and the electrode area is 4cm ². The MEA cell was assembled with an electrolyte of 1M KOH at a circulation rate of 20mL/min and a test temperature of 60 ℃. The test instrument was CHI660e and the cell was subjected to a linear voltammetric scan test of 0-2.5V.

Tensile Strength test A dry film sample of 5X 0.5cm was tested using InstronM3300 electronic universal tester at a tensile rate of 5mm/min.

And (3) testing alkaline stability, namely respectively soaking the prepared anion membrane in NaOH solutions with different temperatures and different concentrations, measuring the conductivity of the anion membrane, and analyzing the alkaline stability of the anion membrane through the change of the conductivity of an electrolyte membrane. The time for which the conductivity remained 90% of the initial conductivity was defined as the alkaline stability time by soaking in 1M KOH at 80 ℃.

Swelling ratio test after vacuum drying at 80 ℃, the dry weight (W _dry) and length (L _dry) of the film samples were recorded. The samples were then immersed in de-aerated deionized water at various temperatures for 12 hours. After wiping the surface for excess moisture, the wet weight (W _wet) and length (L _wet) of the sample were recorded. The water content and swelling degree can be calculated by the following formula:

In a first aspect, an embodiment of the present application provides a polyazulene sulfide anion exchange membrane, where the polyazulene sulfide anion exchange membrane contains a polyazulene sulfide polymer, and the polyazulene sulfide anion exchange membrane has the following structure:

wherein R ₁ is a cationic group, R ₂ is a branching group, a is any integer between 1 and 10000, and b is any integer between 0 and 10000.

The material is polymerized and quaternized to prepare an alkaline anion exchange membrane, wherein a strong dipole moment azulenyl group and a sulfur-containing main chain promote the formation of a reinforced hydrogen bond network and promote high-speed transmission of OH ^-, a branched structure generates high mechanical strength, the water absorption and swelling rate of the anion exchange membrane are greatly reduced, so that the dimensional stability is improved, and meanwhile, a high-stability cationic group and a nucleophilic azulenyl group increase the alkaline stability, and the high OH ^- conductivity, the alkaline stability and the high mechanical strength of the material indicate that the prepared anion exchange membrane can be used as an anion exchange membrane material for alkaline fuel cells and alkaline electrolytic cells.

In a specific embodiment, R ₁ in the embodiment of the present application is preferably one of the following structures:

Wherein n is an integer of 0 or more.

In a specific embodiment, R ₂ in the embodiment of the present application is preferably one of the following structures:

in a second aspect, an embodiment of the present application provides a method for preparing the polyazulene sulfide anion exchange membrane according to the first aspect, the method comprising:

(1) Preparation of the polyazulene sulfide precursor:

(2) Preparation of polyazulene sulfide anion exchange membranes:

Dissolving the cationized azulene thioether in a third organic solvent, collecting an I ^- type film, carrying out ion exchange on the I ^- type film to obtain an OH ^- type film, and collecting the azulene thioether anion exchange film after purification treatment.

It should be noted that the precursor of the azulene thioether in the embodiment of the present application is prepared by firstly placing azulene monomer, branched monomer and Na ₂ S in a certain proportion in a first organic solvent to obtain a mixed solution, rapidly heating the mixed solution, reacting for a certain time, collecting the obtained solid product, washing the polymer solid with deionized water and ethanol, and drying to obtain the azulene thioether.

It should be noted that the method for collecting azulene thioether polymer in the embodiment of the application comprises the steps of filtering to obtain a solid polymer, washing with deionized water for three times, washing with absolute ethyl alcohol for one time, and vacuum drying.

The drying conditions in the present application are not particularly limited, and a product having a constant weight can be obtained. In the embodiment of the application, the temperature of the drying is preferably 80 ℃ and the time is preferably 24 hours.

In the examples of the present application, the reaction was carried out at room temperature under stirring for 24 hours at a dark place.

In the embodiment of the application, the N atom in the azulene-based monomer reacts with methyl iodide to form a quaternary ammonium cation.

In the examples of the present application, ethyl acetate was used as a good solvent for methyl iodide to dissolve unreacted monomers and as a poor solvent for polymers to precipitate the polymers, thereby purifying the polymers.

In a specific embodiment, the molar ratio of the azulene-based monomer to the branching monomer in the embodiment of the present application is preferably 0 to 99:1.

Wherein, when the molar ratio of the azulene-based monomer to the branched monomer is more than 99:1, namely the branched monomer content is too low, the effect of the branched monomer on improving the performance of the anion exchange membrane is weak.

In specific examples, the molar ratio of the sum of the addition amounts of the branching monomer and the azulene-based monomer to the addition amount of Na ₂ S in the examples of the present application is preferably 1:0.9-1.2.

In specific examples, the molar ratio of the sum of the addition amounts of the branching monomer and the azulene-based monomer to Na ₂ S in the examples of the present application is preferably 1:0.9 to 1.5.

Wherein, when the molar ratio of the sum of the addition amounts of the branched monomer and the azulene-based monomer to Na ₂ S is less than 1:1.2, a local polymerization rate too fast may occur, resulting in a too wide molecular weight distribution, and when the molar ratio of the sum of the addition amounts of the branched monomer and the azulene-based monomer to Na ₂ S is more than 1:0.9, the reaction yield and rate may be lowered.

In a specific embodiment, the first organic solvent in the embodiment of the present application is preferably one of dimethyl sulfoxide, N-methylpyrrolidone and N, N-dimethylformamide.

Wherein the first organic solvents play a role in dissolving reactants.

In a specific embodiment, the second organic solvent in the embodiment of the present application is preferably one of acetonitrile, tetrahydrofuran, N-methylpyrrolidone, dimethyl sulfoxide, N-dimethylacetamide, N-dimethylformamide and sulfolane.

Wherein the second organic solvents play a role in dissolving the polymer.

In a third aspect, embodiments of the present application provide a polyazulene sulfide anion exchange membrane as described in the first aspect, and the use of the polyazulene sulfide anion exchange membrane as prepared by the method as described in the second aspect for preparing alkaline fuel cells and alkaline electrolytic cells.

In particular embodiments, the OH ^- conductivity of the polyazulene sulfide anion exchange membranes of embodiments of the present application is preferably at least 100mS/cm at 80 ℃.

The technical method of the present application will be further described with reference to specific examples.

Example 1

This example 1 provides a process for preparing a 6-6' biaazulene crosslinked poly 6-piperidineazulene thioether anion exchange membrane, namely b-PAS-6Pip-BiAz anion exchange membrane, comprising the following specific steps:

(1) Monomer 6- (N-piperidine) -1, 3-dibromoazulene and monomer 1,3,1',3' -tetrabromo-6, 6' continuously azulene were produced according to literature methods (Journal of Organic Chemistry 2019,84 (3), 1257-1275;Tetrahedron 2006,62 (48), 11227-11239).

Anhydrous Na ₂ S (245 mg), 6- (N-piperidine) -1, 3-dibromoazulene (1 g), 1,3,1',3' -tetrabromo-6, 6' azulene (81 mg), naOH (20 mg) were weighed into a kettle, and 20 mLN-methylpyrrolidone (NMP) was added. The temperature is quickly raised to 200 ℃ and the reaction is carried out for 6 hours. And naturally cooling, and washing with deionized water and absolute ethyl alcohol. The product obtained after filtration was dried in vacuo at 80 ℃ for 8h. The dried product was a black solid powder, 0.7g total, 94% yield. 1g of the product was dissolved in 30mL of dimethyl sulfoxide (DMSO), then K ₂CO₃ (0.39 g) and methyl iodide (1 mL) were added, and the reaction was stirred at room temperature in the dark for 24h. To the viscous solution obtained was added 100mL of ethyl acetate. The pale yellow precipitate was filtered, washed three times with water, and dried in an oven at 80℃under vacuum for 24h to give b-PAS-6Pip-BiAz. The chemical structure of the polymer is determined by nuclear magnetism and infrared characterization, and is shown in figure 1, the weight average molecular weight is 7.3 multiplied by 10 ⁵, wherein a is an integer of 0-10000, b is an integer of 0-200, and the polymerization mode of ab corresponding to the groups in brackets is random polymerization.

In order to facilitate understanding of the synthesis process of the 6-6' biaazulene crosslinked poly 6-piperidine azulene thioether (b-PAS-6 Pip-BiAz), the application provides a synthesis route diagram of the 6-6' biaazulene crosslinked poly 6-piperidine azulene thioether (b-PAS-6 Pip-BiAz), as shown in fig. 1, and fig. 1 is a synthesis route diagram of the 6-6' biaazulene crosslinked poly 6-piperidine azulene thioether (b-PAS-6 Pip-BiAz) provided by the application.

(2) Preparation of poly 6-piperidineazulene thioether anion exchange membrane:

b-PAS-6Pip-BiAz (1 g) was dissolved in 30mL DMSO and the polymer solution was filtered through a 0.45 μm polytetrafluoroethylene filter, permeabilized and cast on a clean glass plate. Subsequently, the solution was evaporated at 80 ℃ for 12h,120 ℃ for 12h, and dried at 120 ℃ under vacuum for 24h, completely removing the residual solvent. The dense I-type film was peeled from the glass plate. Ion exchange was performed in 1M KCl solution at 80℃for 12h, followed by washing 3 times with deionized water to remove residual salts and give a Cl ^- -type membrane. In 1M KOH solution, placing at 80 ℃ for 12h for ion exchange, and then washing with deionized water for 3 times under nitrogen atmosphere to obtain the OH ^- type membrane, namely the b-PAS-6Pip-BiAz anion exchange membrane.

Example 2

This example 2 provides a process for preparing a polyazulene sulfide anion exchange membrane, namely a triazulene benzene cross-linked poly 6-piperidineazulene sulfide (b-PAS-6 pip-3 AzPh) anion exchange membrane, comprising the following specific steps:

(1) Monomer 6- (N-piperidine) -1, 3-dibromoazulene and monomer 1,3, 5-tris (2-azulene) benzene were prepared according to literature method (Journal of Organic Chemistry 2019,84 (3), 1257-1275;Tetrahedron 2004,60 (25), 5357-5366). Anhydrous Na ₂ S (232 mg), 6- (N-piperidine) -1, 3-dibromoazulene (1 g) 1,3, 5-tris (2-azulene) benzene (99 mg), naOH (20 mg) were weighed into a reaction kettle, and 20 mLN-methylpyrrolidone (NMP) was added. The temperature is quickly raised to 200 ℃ and the reaction is carried out for 6 hours. And naturally cooling, and washing with deionized water and absolute ethyl alcohol. The product obtained after filtration was dried in vacuo at 80 ℃ for 8h. The dried product was a black solid powder, 0.7g total, 95% yield. 1g of the product was dissolved in 30mL of dimethyl sulfoxide (DMSO), then K ₂CO₃ (0.39 g) and methyl iodide (1 mL) were added, and the reaction was stirred at room temperature in the dark for 24h. To the viscous solution obtained was added ethyl acetate. After filtering the pale yellow precipitate, washing with water three times, and vacuum drying in an oven at 80 ℃ for 24 hours, PAS-6pip was obtained. The chemical structure of the polymer is determined by nuclear magnetism, infrared and ultraviolet symptoms as shown in figure 2, the weight average molecular weight is 7.5 multiplied by 10 ⁵, wherein a is an integer of 0-10000, b is an integer of 0-200, and the polymerization mode of ab corresponding to the groups in brackets is random polymerization.

In order to facilitate understanding of the above-mentioned synthesis process of the triaazulene benzene cross-linked poly 6-piperidine azulene thioether (b-PAS-6 pip-3 AzPh), the present application provides a synthesis route diagram of the triaazulene benzene cross-linked poly 6-piperidine azulene thioether (b-PAS-6 pip-3 AzPh), as shown in fig. 2, fig. 2 is a synthesis route diagram of the triaazulene benzene cross-linked poly 6-piperidine azulene thioether (b-PAS-6 pip-3 AzPh) provided by the present application.

(2) Preparation of Triazulene benzene crosslinked poly 6-piperidineazulene thioether anion exchange membrane:

b-PAS-6pip-3AzPh (1 g) was dissolved in 30mL DMSO and the polymer solution was filtered through a 0.45 μm polytetrafluoroethylene filter, permeabilized and cast on a clean glass plate. Subsequently, the solution was evaporated at 80 ℃ for 12h,120 ℃ for 12h, and dried at 120 ℃ under vacuum for 24h, completely removing the residual solvent. The dense I-type film was peeled from the glass plate. Ion exchange was performed in 1M KCl solution at 80℃for 12h, followed by washing 3 times with deionized water to remove residual salts and give a Cl ^- -type membrane. In 1M KOH solution, the solution is placed at 80 ℃ for 12 hours for ion exchange, and then the solution is washed with deionized water for 3 times under nitrogen atmosphere, so as to obtain an OH ^- type membrane, namely a b-PAS-6pip-3AzPh anion exchange membrane.

Example 3

This example 3 provides a process for preparing a polyazulene sulfide anion exchange membrane, namely a poly 6-piperidineazulene sulfide (PAS-6 pip) anion exchange membrane, comprising the following specific steps:

(1) Monomer 6- (N-piperidine) -1, 3-dibromoazulene was produced according to literature method (Journal of Organic Chemistry 2019,84 (3), 1257-1275). Anhydrous Na ₂ S (232 mg), 6- (N-piperidine) -1, 3-dibromoazulene (1 g), naOH (20 mg) were weighed into a reaction vessel and 20mL of N-methylpyrrolidone (NMP) was added. The temperature is quickly raised to 200 ℃ and the reaction is carried out for 6 hours. And naturally cooling, and washing with deionized water and absolute ethyl alcohol. The product obtained after filtration was dried in vacuo at 80 ℃ for 8h. The dried product was a black solid powder, 0.7g total, 95% yield. 1g of the product was dissolved in 30mL of dimethyl sulfoxide (DMSO), then K ₂CO₃ (0.39 g) and methyl iodide (1 mL) were added, and the reaction was stirred at room temperature in the dark for 24h. To the viscous solution obtained was added ethyl acetate. After filtering the pale yellow precipitate, washing with water three times, and vacuum drying in an oven at 80 ℃ for 24 hours, PAS-6pip was obtained. The chemical structure of the polymer is determined by nuclear magnetism and infrared characterization, and is shown in figure 3, the weight average molecular weight is 6.8X10 ⁵, wherein a is an integer of 0-10000, b is an integer of 0-200, and the polymerization mode of ab corresponding to the groups in brackets is random polymerization.

In order to facilitate understanding of the synthesis process of the poly (6-piperidine) azulene thioether (PAS-6 pip), the application provides a synthesis route diagram of the poly (6-piperidine) azulene thioether (PAS-6 pip), as shown in fig. 3, and fig. 3 is a synthesis route diagram of the poly (6-piperidine) azulene thioether (PAS-6 pip).

(2) Preparation of poly 6-piperidineazulene thioether anion exchange membrane:

PAS-6pip (1 g) was dissolved in 30mL DMSO, the polymer solution was filtered through a 0.45 μm polytetrafluoroethylene filter, the solution was permeabilized and cast onto a clean glass plate. Subsequently, the solution was evaporated at 80 ℃ for 12h,120 ℃ for 12h, and dried at 120 ℃ under vacuum for 24h, completely removing the residual solvent. The dense I-type film was peeled from the glass plate. Ion exchange was performed in 1M KCl solution at 80℃for 12h, followed by washing 3 times with deionized water to remove residual salts and give a Cl ^- -type membrane. In 1M KOH solution, the solution is placed at 80 ℃ for 12 hours for ion exchange, and then the solution is washed with deionized water for 3 times under nitrogen atmosphere, so as to obtain an OH ^- type membrane, namely PAS-6pip anion exchange membrane.

To verify the performance of the polyazulene sulfide anion exchange membranes prepared in examples 1-3, performance tests were performed on polyazulene sulfide anion exchange membranes and commercial FAA3-50 anion exchange membranes, and the test results are shown in the figure.

The b-PAS-6Pip-BiAz anion exchange membrane prepared in this example 1 was shown to have a thickness of 50.+ -.5 microns, an OH ^- conductivity of 155mS/cm at 80 ℃, an ion exchange capacity of 2.4mmol/g, a swelling ratio of 35%, a tensile strength of 68MPa, an elongation at break of 13% and an alkaline stability in 80 ℃ and 1M KOH for 1000 hours. The b-PAS-6pip-3AzPh anion exchange membrane prepared in this example 2 had a thickness of 50.+ -. 5. Mu.m, an OH ^- conductivity of 150mS/cm at 80 ℃, an ion exchange capacity of 2.4mmol/g, a swelling ratio of 46%, a tensile strength of 60MPa, an elongation at break of 13% and an alkaline stability in 1M KOH at 80℃for 1000h. Meanwhile, the PAS-6pip anion exchange membrane prepared in the embodiment 3 has the thickness of 50+/-5 microns, the conductivity of OH ^- at 80 ℃ is 144mS/cm, the ion exchange capacity is 2.4mmol/g, the swelling rate is 55%, the tensile strength is 43MPa, the elongation at break is 12%, and the alkaline stability is kept for 1000 hours in 80 ℃ and 1M KOH, so that the homogeneous anion exchange membrane prepared in the embodiment has the advantages of smaller swelling, proper ion conductivity and anion exchange capacity and good mechanical property, and along with the addition of a branched monomer, the conductivity of OH ^- is increased, the swelling rate is reduced, and the mechanical property is enhanced. Meanwhile, the prepared azulene thioether anion exchange membrane is superior to a commercial FAA 3-50 anion exchange membrane in both conductivity and anion exchange membrane electrolysis water performance.

FIG. 4 is the results of the OH ^- conductivity test of the azulene thioether anion exchange membranes prepared in examples 1,2 and 3. Fig. 5 is the results of the water electrolysis test of the anion exchange membrane of the polyazulene sulfide anion exchange membranes prepared in examples 1,2 and 3.

The foregoing is merely illustrative of the present application, and the present application is not limited thereto, and any person skilled in the art will readily recognize that variations or substitutions are within the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A polyazonium sulfide anion exchange membrane, characterized in that the polyazonium sulfide anion exchange membrane contains a polyazonium sulfide polymer, wherein the polyazonium sulfide polymer has at least one or more of the following structures:

; ; ;or ;

Wherein, _R1 is a cationic group, _R2 is a branched group, a is any integer between 1 and 10000, and b is any integer between 0 and 10000;

_R1 is each individually one or more of the following structures:

, , , , , , , ,

Where n is any integer between 1 and 100;

_R2 is each individually one or more of the following structures:

, , , , , , , , , , , , , , , , , , , ;

In the above structure, the wavy line “﹏” represents the connection point.

2. The ion exchange membrane according to claim 1, characterized in that the membrane thickness is 10-200 μm.

The polymerization mode of the groups in parentheses corresponding to a and b is random polymerization.

3. A method for preparing the polyazine sulfide anion exchange membrane according to any one of claims 1-2, characterized in that it comprises:

(1) Preparation of polyazine sulfide polymer:

_Na₂S , azulene monomer A as shown in Formula 1, and branched monomer _R₂ -Br were placed in a reaction vessel, dissolved in a first organic solvent, heated, and reacted. The solid product was then washed, dried, and collected. The product was dissolved in a second organic solvent, potassium carbonate and iodomethane were added, and the reaction was carried out in the dark. Ethyl acetate was added, and the mixture was purified. The polyazine sulfide polymer was then collected.

;

Formula 1 Azulene monomer A structure

The specific structures of _R1 and _R2 are the same as the corresponding _R1 and _R2 group structures in claim 1, and are one or more of the corresponding _R1 and _R2 group structures in claim 1;

(2) Preparation of polyazine sulfide anion exchange membrane:

The polyazine sulfide polymer is dissolved in a second organic solvent to form a membrane. After drying, the I ^- type membrane is collected, and the I ^- type membrane is subjected to ion exchange to obtain an OH ^- type membrane. The polyazine sulfide anion exchange membrane is then collected.

4. The method for preparing the polyazine sulfide anion exchange membrane according to claim 3, characterized in that the molar ratio of the sum of the amount of azulene monomer and the amount of branched monomer added in step (1) to the amount of _Na₂S added is 1:0.9-1.5, and the molar ratio of the amount of branched monomer and azulene monomer added is 0-1:1.

5. The method for preparing the polyazine sulfide anion exchange membrane according to claim 4, characterized in that the molar ratio of the sum of the amounts of azulene monomer and the branched monomer added in step (1) to the amount of _Na₂S added is 1:0.9-1.2, and the molar ratio of the amounts of the branched monomer and the azulene monomer added is 0.05-0.5:1.

6. The method for preparing the polyazine sulfide anion exchange membrane according to claim 3, characterized in that the reaction temperature is greater than 150°C and the reaction time is greater than 4 hours.

7. The method for preparing the polyazine sulfide anion exchange membrane according to claim 6, characterized in that the reaction temperature is 150-220℃ and the reaction time is 4-24 hours.

8. The method for preparing the polyazine sulfide anion exchange membrane according to claim 3, characterized in that the first organic solvent is one or more of dimethyl sulfoxide, N-methylpyrrolidone and N,N-dimethylformamide, and the concentration of _Na₂S in the first organic solvent is 0.1-2 mol/L.

9. The method for preparing the polyazine sulfide anion exchange membrane according to claim 3, characterized in that the second organic solvent is one or more of acetonitrile, tetrahydrofuran, N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylacetamide, N,N-dimethylformamide and sulfolane;

In step (1), the concentration of the product in the second organic solvent is 0.1-1 g/mL, the final concentration of potassium carbonate is 1 mol/L, and the final concentration of iodomethane is 1 g/mL.

10. The application of a polyazine sulfide anion exchange membrane according to any one of claims 1-2, or a polyazine sulfide anion exchange membrane prepared by any one of claims 3-9, as a separator in an alkaline fuel cell or an alkaline electrolyzer.

11. The application according to claim 10, wherein the polyazine sulfide anion exchange membrane has an ^OH- conductivity of at least 100 mS/cm at 80 °C.