Polymers and methods for their preparation and use

Abstract

The present application provides a polymer and its preparation method and use, the polymer having a structure shown in Formula 1, wherein M is derived from a ketone monomer, Ar is derived from an aromatic ring conjugated monomer, and X + is a monovalent cation, x1, y1, and z1 are the mole fractions of each block, and 0

Description

[Technical Field]

[0001] This application relates to polymers, in particular to polymers and their preparation and use, in the field of fuel cell technology. [Background technology]

[0002] With the development of science and technology and the accelerating march of humanity toward carbon neutrality, electrochemical energy storage and conversion technologies such as fuel cells, electrolyzed water, and energy storage technologies are considered one of the most promising solutions for reducing dependence on fossil fuels and providing clean energy. Among them, proton exchange membrane (PEM)-based fuel cells, electrolyzed water, and energy storage battery technologies are currently the focus of research in countries around the world.

[0003] Proton exchange membranes (PEMs) transport protons within the membrane and separate the cathode and anode reactants. Proton conductivity is one of the important properties of PEMs and reflects the rate at which protons participate in the cathode and anode reactions. Protons within the membrane are conducted by a transport mechanism dependent on water molecules, so for better proton conduction, the PEM must be in a favorable hydration state. A desirable PEM must have high proton conductivity, mechanical stability, moisture retention, and excellent processability.

[0004] At present, many research teams at home and abroad are conducting research to improve the performance of PEM, but the improvements are too limited to simultaneously meet the various performance requirements mentioned above. Summary of the Invention [Problem to be solved by the invention]

[0005] The present application provides a polymer that is relatively excellent in cation-conducting ability, mechanical strength, and process controllability, and is therefore advantageous in improving the performance of cation-exchange membranes.

[0006] The present application further provides a method for preparing the above polymer, and by selecting an appropriate main chain unit and modifying group, a polymer that improves the performance of a cation exchange membrane can be obtained.

[0007] The present application further provides a cation exchange membrane comprising the above polymer, which not only has excellent ion conductivity and mechanical strength, but also has strong process controllability.

[0008] The present application further provides a fuel cell, which includes the above-described cation exchange membrane and therefore has excellent power generation efficiency.

[0009] The present application further provides an electrolytic water device, which includes the above-mentioned cation exchange membrane, thereby significantly improving electrolysis efficiency. [Means for solving the problem]

[0010] The present application provides a polymer, the polymer having the structure shown in Formula 1: [ka] In Formula 1, M is derived from a ketone monomer, Ar is derived from an aromatic ring conjugated monomer, and X + is a monovalent cation, x1, y1, and z1 are the mole fractions of each block, respectively, and 0 <x1≦1、0≦z1<1、0≦y1<1、x1+y1+z1=1であり、 n is an integer of 1 to 6, m1 is an integer of 0 to 6, and m2 is an integer of 1 to 8. In the above polymer, X + is H + is.

[0011] In the above-mentioned polymer, the ketone monomer is at least one selected from the compounds represented by the following formula:

[0012] [Chemical formula] In the formula, p1 and p2 are each independently an integer from 0 to 10, k is an integer from 1 to 6, q is an integer from 0 to 5, and R1 to R5 are each independently selected from hydrogen, fluorine, and methyl.

[0013] In the above-mentioned polymer, the aromatic ring-conjugated monomer is at least one selected from compounds represented by the following formula.

[0014] [Chemical formula] In the formula, m is an integer from 0 to 3, j is an integer from 1 to 6, R6 - R 17 are each independently selected from hydrogen, substituted or unsubstituted C1-C18 alkyl, substituted or unsubstituted C2-C18 alkenyl, and substituted or unsubstituted C2-C18 alkynyl, and R 18 is selected from C1-C18 alkyl, C2-C18 alkenyl, and C2-C18 alkynyl, and R 19 -R 20 are each independently selected from hydrogen, fluorine, and methyl.

[0015] In the above-mentioned polymer, the polymer is prepared by a process including reacting a raw material system containing a polymer precursor, a hydrophilic unit, and a sulfonate in the presence of an acid binder to obtain the polymer. The polymer precursor has a structure of Formula 1a, and the hydrophilic unit has a structure of Formula 1b.

[0016] [Chemical formula] In Formula 1a, x and y are each the molar fraction of each block, and 0 < x ≦ 1, x + y = 1, R0 is selected from hydrogen or tert-butoxycarbonyl, m1 is an integer from 0 to 6, and m2 is an integer from 1 to 8.

[0017] In the above-mentioned polymer, the hydrophilic unit is preferably any one of 3-bromopropyl methyl ether, 1-bromo-2-(2-methoxyethoxy)ethane, diethylene glycol-2-bromoethyl methyl ether, and 1-bromo-5-methoxypentane.

[0018] This application provides a method for preparing the polymer according to any one of the above items. The preparation method includes reacting a raw material system containing a polymer precursor, a hydrophilic unit, and a sulfonate in the presence of an acid binder to obtain the polymer. The polymer precursor has a structure of Formula 1a, and the hydrophilic unit has a structure of Formula 1b.

[0019]

Chemical formula

[0020] In the above-mentioned preparation method, the polymer precursor is prepared by a method including a process of reacting a mixed liquid system containing a ketone monomer, an aromatic ring conjugated monomer, and a carbazole monomer in the presence of a catalyst to obtain a polymer precursor. The catalyst is preferably at least one of trifluoroacetic acid, trifluoromethanesulfonic acid, and methanesulfonic acid.

[0021] In the above-mentioned preparation method, the sulfonate is preferably any one of sodium 3-bromo-1-propanesulfonate, sodium 4-bromo-1-butanesulfonate, sodium 5-bromo-1-pentanesulfonate, sodium 6-bromo-1-hexanesulfonate, sodium 7-bromo-1-heptanesulfonate, sodium 8-bromo-1-octanesulfonate, and sodium 9-bromo-1-nonanesulfonate.

[0022] The present application further provides a cation exchange membrane, the composition of which comprises the polymer described in any one of the above items.

[0023] The present application further provides a fuel cell comprising the above-described cation exchange membrane.

[0024] The present application further provides an electrolyzed water device comprising the above-described cation exchange membrane. [Effects of the Invention]

[0025] The presence of sulfonic acid groups in the branched chains of the polymer not only promotes the polymer's moisture absorption and moisture retention to a certain extent, but also allows the sulfonic acid groups to be attached to the branched chains in the form of salts, thereby enabling the content of sulfonic acid groups in the polymer to be controlled, thereby enabling the polymer's moisture absorption and moisture retention to be controlled and accurately meet the needs of use. Furthermore, the main chain contains carbazole groups but does not contain easily attackable groups such as ether groups, carbonyl groups, or sulfone groups, resulting in the polymer's high stability, chemical stability, and mechanical strength. Therefore, the polymer of the present application has excellent performance in ionic conductivity and mechanical strength, and in particular, it can be precisely adjusted according to the needs of use, ultimately achieving controllable ionic conductivity. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a 1H-NMR spectrum of the main chain of the polymer of Example 19. [Figure 2] FIG. 1 is a comparison diagram of current density-voltage curves when the proton exchange membranes of Example 1-2 and Comparative Example 1-2 are assembled in an electrolysis tank. DETAILED DESCRIPTION OF THE INVENTION

[0027] To make the objectives, technical solutions and advantages of the present application clearer, the following uses examples of the present application to clearly and completely describe the technical solutions according to the examples of the present application. Needless to say, the described examples are only part of the examples of the present application, not all the implemented examples. All other examples obtained by those skilled in the art based on the examples of the present application without creative labor shall fall within the protection scope of the present application.

[0028] In a first aspect, the present application provides a polymer, and the polymer has a structure represented by Formula 1.

[0029]

Chemical formula

[0030] The polymer of the present application contains at least three types of blocks represented by Formula 1, and the molar fractions of the three types of blocks in the polymer are respectively represented as x1, y, and z1.

[0031] It should be noted that the present application does not limit the molecular weight of the polymer, and the specific molecular weight of the polymer can be adjusted by controlling the addition amount of the monomer according to actual needs. In addition, the present application does not limit the arrangement structure of the three types of blocks of the polymer, and the three types of blocks can be combined in any arrangement. In addition to the sequential combination of the block represented by x1, the block represented by z1, and the block represented by y1 shown in Formula 1, for example, the polymer may also include a block copolymer in which the block represented by x1, the block represented by y1, and the block represented by z1 are sequentially combined.

[0032] According to the technical solution provided by the present application, the inclusion of the above-mentioned polymer in the composition of a cation exchange membrane can significantly improve the performance of the cation exchange membrane in terms of ionic conductivity, chemical stability, and mechanical strength. Based on this phenomenon, the inventors conducted an analysis and concluded that, on the one hand, the sulfonic acid groups on the branched chains help improve the polymer's hygroscopicity and moisture retention. Since cation conduction depends on water molecules in the environment, establishing a good, high-humidity conductive environment for the polymer may be more conducive to maintaining long-term, highly efficient cation conduction. On the other hand, because the main chain of the polymer containing carbazole groups does not contain easily attackable reactive groups (e.g., ether, carbonyl, sulfone), the polymer can exhibit excellent chemical and mechanical stability over long-term use environments, reducing or avoiding polymer decomposition due to poor chemical stability and polymer breakage due to poor mechanical stability, resulting in a very long service life for cation conduction. Furthermore, the polymer's excellent moisture retention can also prevent the polymer from becoming brittle due to water loss, thereby improving the polymer's mechanical properties to a certain extent.

[0033] Furthermore, when the z1 of the polymer is greater than zero, the hydrophilic branched chains of the polymer help to further improve the moisture retention of the cation exchange membrane, induce self-organization within the ion exchange membrane to build interconnected proton transport channels, reduce dead ends, and form highly efficient ion cluster structures, thereby further improving the ionic conductivity of the cation exchange membrane in low-humidity environments.

[0034] Furthermore, the combination of flexible branched chains, including sulfonic acid group branched chains and the above-mentioned hydrophilic branched chains, with a rigid main chain containing carbazole also promotes the occurrence of microphase separation in the polymer, which is useful for improving the cation-conducting effect.

[0035] It is worth noting that the polymers of the present application not only contribute to improved ionic conductivity, chemical stability, and mechanical strength, but also have the advantage of being able to control related properties. This is because, in preparing the polymer, by controlling parameters such as the selection of raw materials and the order of steps, it is possible to prevent the sulfonic acid group-providing units from participating in the polymerization reaction. Instead, it is sufficient to select corresponding monomers to polymerize with each other to form polymer units, and then control the ratio of the polymer units and the sulfonic acid group-providing units so that the sulfonic acid groups are introduced into the polymer as branched chains. Because the polymerization reaction is a chain-induced reaction, introducing the sulfonic acid groups into the polymer as branched chains can avoid the difficulty in controlling the polymerization reaction process, which may result in the failure to obtain a polymer with the desired doping amount of sulfonic acid group units.

[0036] Therefore, the special composition structure of the polymer of the present application allows for precise control of the doping ratio of sulfonic acid groups therein, ensuring that the final polymer has a target doping ratio of sulfonic acid groups. This controllability not only enables consistency in the same batch of products and improves production efficiency, but also facilitates the construction of polymers with different doping ratios of sulfonic acid groups, thereby realizing product versatility and meeting the different needs of different environments in terms of ion conduction performance, mechanical properties, etc.

[0037] The present application provides a monovalent cation X of formula 1 + It is not limited to a specific type, for example, H + , Na + , K. + , Ag + , Li + In one embodiment, when the polymer is used in a proton exchange membrane, the monovalent cation X + is H + is.

[0038] The present application does not limit the specific form of the ketone monomer, and any monomer that can provide a carbonyl can be used as the ketone monomer of the present application. For example, the ketone monomer can be derived from at least one compound represented by the following C1-C12 structural formula:

[0039] [ka] In the formula, p1 and p2 are each independently an integer of 0 to 10, k is an integer of 1 to 6, q is an integer of 0 to 5, and R1 to R5 are each independently selected from hydrogen, fluorine, and methyl.

[0040] The present application does not limit the specific form of the aromatic ring conjugated monomer, and any monomer that can provide an aromatic ring can be used as the aromatic ring conjugated monomer of the present application. For example, the aromatic ring conjugated monomer can be derived from at least one compound represented by the following structural formulas A1 to A7.

[0041] [ka] In the formula, m is an integer of 0 to 3, j is an integer of 1 to 6, and R6 to R 17 are each independently selected from hydrogen, substituted or unsubstituted C1-C18 alkyl, substituted or unsubstituted C2-C18 alkenyl, and substituted or unsubstituted C2-C18 alkynyl; R 18 is selected from C1-C18 alkyl, C2-C18 alkenyl, and C2-C18 alkynyl; R 19 -R 20 are each independently selected from hydrogen, fluorine, and methyl.

[0042] The polymer of the present application is The polymer can be prepared by a method comprising the steps of: reacting a raw material system containing a polymer precursor, a hydrophilic unit, and a sulfonate in the presence of an acid binder to obtain a polymer; The polymer precursor has a structure of Formula 1a, and the hydrophilic unit has a structure of Formula 1b.

[0043]

Chemical formula

[0044] Exemplarily, when both m1 and m2 are 3, the hydrophilic unit is as shown in Formula 1b-1.

Chemical formula

[0045] The hydrophilic unit of the present application can be any one selected from 3-bromopropyl methyl ether, 1-bromo-2-(2-methoxyethoxy)ethane, diethylene glycol-2-bromoethyl methyl ether, and 1-bromo-5-methoxypentane.

[0046] In a specific implementation process, first, the polymer precursor, the hydrophilic unit, and the sulfonate are dissolved in a solvent to obtain a raw material system, and then an acid binder is added to carry out the reaction. After that, post-treatment including precipitation treatment, washing treatment, and drying treatment is performed on the reaction solution to obtain the polymer.

[0047] In the preparation process, by controlling the respective mass ratios of the sulfonate and the hydrophilic unit to the polymer precursor, it is possible to control the ratio of the sulfonate group and the hydrophilic group in the polymer, and a polymer that meets the target requirements can be obtained.

[0048] The cation in the sulfonate corresponds to X in the polymer + For example, X + is Na +When it is necessary to prepare a polymer that is, sodium sulfonate salt is selected, but X + is K + When it is necessary to prepare a polymer that is, it should be noted that potassium sulfonate salt is selected. On the other hand, X + is H + When it is necessary to prepare a polymer that is, there is no restriction on the metal cation in the selected sulfonate, but an acid exchange treatment is required after the preparation so that the metal cation in it is exchanged with H + .

[0049] In a second aspect, the present application provides a method for preparing the polymer of the first aspect described above. The preparation method includes reacting a raw material system containing a polymer precursor, a hydrophilic unit, and a sulfonate in the presence of an acid binder to obtain a polymer, The polymer precursor has a structure of Formula 1a, and the hydrophilic unit has a structure of Formula 1b.

[0050] [Chemical formula] In Formula 1a, x and y are respectively the molar fractions of each block, and 0 < x ≤ 1, x + y = 1. R0 is selected from hydrogen or tert-butoxycarbonyl, m1 is an integer from 0 to 6, and m2 is an integer from 1 to 8.

[0051] The raw material system is a solution system in which a polymer precursor, a hydrophilic unit, and a sulfonate are dissolved. The present application does not limit the selection of the solvent of the raw material system. For example, at least one of N-methylpyrrolidone, dimethyl sulfoxide, or dimethylacetamide is included.

[0052] An acid binder is added to the raw material system and reacted. In the presence of the acid binder, the hydrophilic unit and the sulfonate are reacted with the carbazole unit in the polymer precursor to finally obtain a polymer represented by Formula (1). It can be understood that after the reaction is completed, post-treatments such as precipitation treatment, washing treatment, and drying treatment need to be performed on the reaction solution.

[0053] The precipitation treatment means that the reaction solution is reacted with a precipitant to precipitate a polymer, such as at least one selected from the group consisting of water, ethyl acetate, ethanol, methanol, isopropanol, and n-propanol. The precipitate is then filtered, and the separated polymer is washed with deionized water and dried to obtain the polymer.

[0054] The present application does not limit the relevant preparation parameters of the preparation method so long as the polymer can be synthesized.

[0055] For example, the acid binder is at least one selected from anhydrous potassium carbonate, sodium hydroxide, potassium hydroxide, or sodium hydride, the reaction time is 24 to 72 hours, the reaction temperature is 60 to 90°C, and the mass ratio between the polymer precursor, the hydrophilic unit, and the sulfonate can be adjusted according to the differentiated needs of related properties such as ionic conductivity, mechanical strength, etc., and X + Na + In the case where the sulfonate is, for example, any one selected from sodium 3-bromo-1-propanesulfonate, sodium 4-bromo-1-butanesulfonate, sodium 5-bromo-1-pentanesulfonate, sodium 6-bromo-1-hexanesulfonate, sodium 7-bromo-1-heptanesulfonate, sodium 8-bromo-1-octanesulfonate, and sodium 9-bromo-1-nonanesulfonate.

[0056] In one specific embodiment, the polymer precursor shown in formula 1a is The polymer precursor is prepared by a method including a process of reacting a mixed liquid system containing a ketone monomer, an aromatic ring conjugated monomer, and a carbazole monomer in the presence of a catalyst to obtain a polymer precursor, the catalyst being at least one selected from trifluoroacetic acid, trifluoromethanesulfonic acid, and methanesulfonic acid. When the catalyst is a mixture of various compounds, the present application does not limit the mass ratio between the compounds. In one embodiment, the catalyst is a mixture of trifluoroacetic acid and trifluoromethanesulfonic acid, and the mass ratio between the two is 1:1.

[0057] The selection of the ketone monomer and the aromatic ring conjugated monomer is as described above and will not be repeated here. Specifically, the carbazole monomer is selected from the compounds represented by formula 1a-1 or 1a-2. [ka]

[0058] The solvent in the above mixed liquid system may be, for example, at least one selected from dichloromethane, trichloromethane, and tetrahydrofuran, and the reaction temperature is -15 to 30°C.

[0059] Furthermore, the molar ratio of the ketone monomer to the carbazole monomer is 1-2:1, the ketone monomer:carbazole monomer:aromatic ring=(1-2):a:b(a+b=1), and the molar ratio of the ketone monomer to the catalyst is 1:1-20.

[0060] After the reaction is complete, the reaction system must be purified to obtain the polymer precursor. The purification process involves the sequential steps of precipitation, dissolution, and reprecipitation. Specifically, the reaction solution is reacted with a precipitant to precipitate a precipitate from the system, and then the precipitate is dissolved using a solubilizer to obtain a product solution. The product solution is then reprecipitated by adding the precipitant, and the resulting precipitate is washed, filtered, and dried to finally obtain a purified polymer precursor.

[0061] In the above purification treatment, the precipitant is, for example, at least one selected from methanol, ethanol, ethyl acetate, water, isopropanol, and n-propanol, and the dissolving agent is, for example, at least one selected from N-methylpyrrolidone, dimethyl sulfoxide, dimethylformamide, and dimethylacetamide.

[0062] In a third aspect, the present application provides a cation exchange membrane, the composition of which comprises the polymer of the first aspect described above.

[0063] The composition of the cation exchange membrane of the present invention contains the above-mentioned polymer, and therefore has excellent ionic conductivity and mechanical strength.

[0064] The specific type of cations that the cation exchange membrane of the present invention conducts is the X of the polymer. + correlates with.

[0065] X + Na + or K + In this case, the cation exchange membrane is applied to the chlor-alkali industry or the field of electrodialysis, and Na + or K + This will be to realize the exchange of X + H + In this case, the cation exchange membrane actually becomes a proton exchange membrane and is applied in the fields of fuel cells, water electrolysis, and H + Conduction of the above can be achieved.

[0066] The present application does not limit the preparation method of the cation exchange membrane, and examples thereof include a method in which the cation exchange membrane is obtained by dissolving a polymer, tape casting, and then drying.

[0067] In preparing a proton exchange membrane, the present application does not limit the specific timing of the acid exchange treatment. For example, the polymer may be subjected to the acid exchange treatment and then to a membrane formation treatment such as tape casting, or the polymer may be subjected to the membrane formation treatment and then to the acid exchange treatment.

[0068] The acid exchange treatment in this application refers to immersing the object to be exchanged in an acid solution. The acid solution is selected from sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid, and the acid concentration is 1 to 5 mol / L. The immersion time is determined by the acid concentration and sulfonate content, and is generally 12 to 72 hours.

[0069] In a fourth aspect, the present application provides a fuel cell comprising the above-described cation exchange membrane. Specifically, the cation exchange membrane serves as an electrolyte separator for conducting hydrogen ions in the fuel cell. The structure of the fuel cell of the present application is not significantly different from the structure of current fuel cells, except that the above-described cation exchange membrane is used as the electrolyte separator of the fuel cell of the present application.

[0070] Since the fuel cell of the present invention is provided with the above-described cation exchange membrane, the electrical performance of the fuel cell, including the cycle performance, can be significantly improved.

[0071] In a fifth aspect, the present application further provides an electrolyzed water device comprising the above-mentioned cation exchange membrane. Specifically, the cation exchange membrane is a proton exchange membrane for conducting hydrogen ions in the electrolyzed water device. The structure of the electrolyzed water device of the present application is not significantly different from the structure of current electrolyzed water devices, except that the above-mentioned cation exchange membrane is used as the proton exchange membrane of the electrolyzed water device of the present application.

[0072] Since the electrolytic water device of the present invention is equipped with the above-mentioned cation exchange membrane, the electrolysis efficiency of the electrolytic water device can be significantly improved, and the yield of hydrogen gas can be increased.

[0073] The polymer of the present invention will be described in detail below using specific examples. [Example]

[0074] Example 1 The method for preparing the polymer and proton exchange membrane of this example includes the following steps 1) to 3): 1) Carbazole monomer, biphenyl monomer, and butanedione monomer were dissolved in dichloromethane to obtain a mixed solution with a solid content of 10 wt.%. While stirring at 0°C, trifluoromethanesulfonic acid was slowly added dropwise as a catalyst to the mixed solution. The molar ratio of carbazole monomer, biphenyl monomer, butanedione monomer, and catalyst was 3:1:4:50. After reacting at room temperature for 10 hours, the reaction solution was slowly poured into methanol for precipitation and filtered to obtain a white solid crude product. The crude product was then dissolved in dimethylformamide and slowly poured into methanol again for thorough precipitation and purification. A white fibrous solid was obtained, which was filtered and washed three times with deionized water to obtain the purified polycarbazole-biphenyl-butanedione copolymer. 2) The purified polycarbazole-biphenyl-butanedione copolymer is dissolved in dimethyl sulfoxide, and after complete dissolution, anhydrous potassium carbonate, 3-bromo-1-propanesulfonic acid sodium monomer, and 3-bromopropyl methyl ether, a hydrophilic monomer, are added to obtain a mixture of the polycarbazole-biphenyl-butanedione copolymer, anhydrous potassium carbonate, 3-bromo-1-propanesulfonic acid sodium monomer, and 3-bromopropyl methyl ether. The molar ratio is 5 The reaction was carried out with stirring at 80°C for 72 hours in a ratio of 2:4:1. After the reaction was completed, the reaction solution was allowed to cool to room temperature, and then slowly poured into deionized water to precipitate the polymer. The precipitate was then filtered and washed with deionized water three times to obtain the polymer of this example. 3) The dried polymer was dissolved in dimethyl sulfoxide to obtain a membrane-forming solution, which was then tape-cast to form a membrane. The membrane was then immersed in 1 mol / L sulfuric acid to perform ion exchange, yielding the proton exchange membrane of this example.

[0075] Example 2 The preparation method of the polymer and proton exchange membrane in this example is almost the same as that in Example 1, except for the ratio of raw materials in step 1). Specifically, carbazole monomer, triphenyl monomer, and trifluoroacetophenone monomer were dissolved in dichloromethane to obtain a mixed liquid system with a solid content of 10 wt.%. Trifluoromethanesulfonic acid was slowly added dropwise as a catalyst to the mixed liquid system while stirring at 0°C. The molar ratio of carbazole monomer, biphenyl monomer, trifluoroacetophenone monomer, and catalyst was 3:1:4:60. The other experimental steps were the same as in Example 1.

[0076] Example 3 The preparation method of the polymer and proton exchange membrane in this example was almost the same as that in Example 1, except for the ratio of raw materials in step 1). Specifically, carbazole monomer, triphenyl monomer, and trifluoroacetophenone monomer were dissolved in dichloromethane to obtain a mixed liquid system with a solids content of 15 wt.%. Trifluoromethanesulfonic acid as a catalyst was slowly added dropwise to the mixed liquid system while stirring at 0°C, and the molar ratio of carbazole monomer, biphenyl monomer, trifluoroacetophenone monomer, and catalyst was 3:1:4:40.

[0077] Example 4 The preparation method of the polymer and proton exchange membrane of this example is almost the same as that of Example 1, except for the ratio of raw materials in step 1). Specifically, carbazole monomer, fluorene, and trifluoroacetone monomer were dissolved in dichloromethane to obtain a mixed liquid system, and the solid content of the mixed liquid system was 10 wt.%. Trifluoromethanesulfonic acid as a catalyst was slowly added dropwise to the mixed liquid system while stirring at 0°C, and the molar ratio of carbazole monomer, fluorene, trifluoroacetone monomer, and catalyst was 3:1:4:80.

[0078] Example 5 The preparation method of the polymer and proton exchange membrane in this example was almost the same as that in Example 1, except for the ratio of the raw materials in step 1). Specifically, carbazole monomer, 1,2-diphenylethane, and 2,3-hexanedione monomer were dissolved in dichloromethane to obtain a mixed liquid system with a solid content of 15 wt.%. Trifluoroacetic acid as a catalyst was slowly added dropwise to the mixed liquid system while stirring at 0°C. The molar ratio of carbazole monomer, 1,2-diphenylethane, 2,3-hexanedione, and catalyst was 4:1:5:70.

[0079] Example 6 The preparation method of the polymer and proton exchange membrane in this example was almost the same as that in Example 1, except for the ratio of the raw materials in step 1). Specifically, carbazole monomer, methylcarbazole, and butanedione monomer were dissolved in dichloromethane to obtain a mixed liquid system with a solid content of 10 wt.%. Trifluoroacetic acid as a catalyst was slowly added dropwise to the mixed liquid system while stirring at 0°C, and the molar ratio of carbazole monomer, methylcarbazole, butanedione monomer, and catalyst was 4:1:5:70.

[0080] Example 7 The preparation method of the polymer and proton exchange membrane of this example is almost the same as that of Example 1, except for the different ratio of raw materials in step 1). Specifically, carbazole monomer, ethylcarbazole, and trifluoroacetophenone monomer were dissolved in dichloromethane to obtain a mixed liquid system, and the solid content of the mixed liquid system was 10 wt.%. Trifluoroacetic acid and trifluoromethanesulfonic acid as catalysts were slowly added dropwise to the mixed liquid system while stirring at 0°C, and the carbazole monomer, ethylcarbazole, trifluoroacetophenone monomer, trifluoroacetic acid, and trifluoromethanesulfonic acid catalyst were mixed. The molar ratio is 5 :1:6:60:60.

[0081] Example 8 The preparation method of the polymer and proton exchange membrane of this example is almost the same as that of Example 1, except for the different ratio of raw materials in step 1). Specifically, carbazole monomer, propylcarbazole, and trifluoropyruvic acid methyl ester monomer were dissolved in dichloromethane to obtain a mixed liquid system, and the solid content of the mixed liquid system was 10 wt.%. Trifluoroacetic acid and trifluoromethanesulfonic acid as catalysts were slowly added dropwise to the mixed liquid system while stirring at 0°C, and the carbazole monomer, propylcarbazole, trifluoropyruvic acid methyl ester monomer, trifluoroacetic acid, and trifluoromethanesulfonic acid catalyst were mixed. The molar ratio is 4 :1:5:5:75.

[0082] Example 9 The preparation method of the polymer and proton exchange membrane of this example is almost the same as that of Example 1, except for the different ratio of raw materials in step 1). Specifically, carbazole monomer, m-triphenyl, and trifluoroacetone monomer were dissolved in dichloromethane to obtain a mixed liquid system, and the solid content of the mixed liquid system was 15 wt.%. Trifluoromethanesulfonic acid as a catalyst was slowly added dropwise to the mixed liquid system while stirring at 0°C, and the carbazole monomer, m-triphenyl, trifluoroacetone monomer, and catalyst were mixed. The molar ratio is 4 :1:5:75.

[0083] Example 10 The preparation method of the polymer and proton exchange membrane of this example is almost the same as that of Example 1, except that a part of step 1) and a part of step 2) are different from those of Example 1. Specifically, 1) Carbazole monomer, 9,10-dihydrophenanthrene, and 2,3-hexanedione monomer were dissolved in dichloromethane to obtain a mixed liquid system, and the solid content of the mixed liquid system was 15 wt.%. Trifluoroacetic acid and trifluoromethanesulfonic acid were slowly added dropwise to the mixed liquid system as catalysts while stirring at 0°C, and the carbazole monomer, 9,10-dihydrophenanthrene, 2,3-hexanedione monomer, trifluoroacetic acid, and trifluoromethanesulfonic acid were reacted. The molar ratio is 4The other steps were the same as in step 1) of Example 1. 2) The purified copolymer is dissolved in dimethyl sulfoxide. When it is completely dissolved, anhydrous potassium carbonate, sodium 3-bromo-1-propanesulfonate monomer, and hydrophilic monomer 1-bromo-2-(2-methoxyethoxy)ethane are added to the copolymer. The copolymer, anhydrous potassium carbonate, sodium 3-bromo-1-propanesulfonate monomer, and hydrophilic monomer 1-bromo-2-(2-methoxyethoxy)ethane are mixed. The molar ratio is 5 The ratio was 2:4:1, and the other steps were the same as in step 2) of Example 1.

[0084] Example 11 The preparation method of the polymer and proton exchange membrane of this example is almost the same as that of Example 1, except that a part of step 1) and a part of step 2) are different from those of Example 1. Specifically, 1) Carbazole monomer, 9,10-dihydrophenanthrene, and 2,3-hexanedione monomer were dissolved in dichloromethane to obtain a mixed liquid system, and the solid content of the mixed liquid system was 15 wt.%. Trifluoroacetic acid and trifluoromethanesulfonic acid were slowly added dropwise to the mixed liquid system as catalysts while stirring at 0°C, and the carbazole monomer, 9,10-dihydrophenanthrene, 2,3-hexanedione monomer, trifluoroacetic acid, and trifluoromethanesulfonic acid were reacted. The molar ratio is 5 The ratio was 1:6:6:100. The other steps were the same as in step 1) of Example 1. 2) The purified copolymer is dissolved in dimethyl sulfoxide. When it is completely dissolved, anhydrous potassium carbonate, sodium 6-bromo-1-hexanesulfonate monomer, and hydrophilic monomer diethylene glycol-2-bromoethyl methyl ether are added to the copolymer. The copolymer, anhydrous potassium carbonate, sodium 6-bromo-1-hexanesulfonate monomer, and hydrophilic monomer diethylene glycol-2-bromoethyl methyl ether are mixed. The molar ratio is 5 The ratio was 2:4:1, and the other steps were the same as in step 2) of Example 1.

[0085] Example 12 The preparation method of the polymer and proton exchange membrane of this example is almost the same as that of Example 11, except for the ratio of the raw materials in step 1). Specifically, carbazole monomer, triphenyl, and 3,4-hexanedione monomer were dissolved in dichloromethane to obtain a mixed liquid system, and the solid content of the mixed liquid system was 15 wt.%. Trifluoromethanesulfonic acid as a catalyst was slowly added dropwise to the mixed liquid system while stirring at 0°C, and the carbazole monomer, triphenyl, 3,4-hexanedione monomer, and catalyst were mixed. The molar ratio is 3 :1:4:70.

[0086] Example 13 The preparation method of the polymer and proton exchange membrane of this example is almost the same as that of Example 11, except for the ratio of the raw materials in step 1). Specifically, carbazole monomer, triphenyl, and 3,4-hexanedione monomer were dissolved in dichloromethane to obtain a mixed liquid system, and the solid content of the mixed liquid system was 10 wt.%. Trifluoromethanesulfonic acid as a catalyst was slowly added dropwise to the mixed liquid system while stirring at 0°C, and the carbazole monomer, triphenyl, 3,4-hexanedione monomer, and catalyst were mixed. The molar ratio is 3 :1:4:80.

[0087] Example 14 The preparation method of the polymer and proton exchange membrane of this example is almost the same as that of Example 11, except for the different ratio of raw materials in step 1). Specifically, carbazole monomer, 1,2-diphenylethane, and 1,1,1-trifluoro-2-butanone monomer were dissolved in dichloromethane to obtain a mixed liquid system, and the solid content of the mixed liquid system was 10 wt.%. Trifluoromethanesulfonic acid as a catalyst was slowly added dropwise to the mixed liquid system while stirring at 0°C, and the carbazole monomer, 1,2-diphenylethane, 1,1,1-trifluoro-2-butanone monomer, and catalyst were mixed. The molar ratio is 3 :1:5:50.

[0088] Example 15 The preparation method of the polymer and proton exchange membrane of this example is almost the same as that of Example 1, except that a part of step 1) and a part of step 2) are different from those of Example 1. Specifically, 1) Carbazole monomer, 1,3-diphenylpropane, and trifluoroacetophenone monomer were dissolved in dichloromethane to obtain a mixed liquid system, and the solid content of the mixed liquid system was 10 wt.%. Trifluoromethanesulfonic acid as a catalyst was slowly added dropwise to the mixed liquid system while stirring at 0°C, and the carbazole monomer, 1,3-diphenylpropane, trifluoroacetophenone monomer, and the catalyst were mixed. The molar ratio is 4 The other steps were the same as in step 1) of Example 1. 2) The purified copolymer is dissolved in dimethyl sulfoxide. When it is completely dissolved, sodium hydride, sodium 5-bromo-1-pentanesulfonate monomer, and hydrophilic monomer 1-bromo-5-methoxypentane are added to the copolymer. The copolymer, sodium hydride, sodium 5-bromo-1-pentanesulfonate monomer, and hydrophilic monomer 1-bromo-5-methoxypentane are mixed. The molar ratio is 4 The ratio was 2:3:1, and the other steps were the same as in step 2) of Example 1.

[0089] Example 16 The preparation method of the polymer and proton exchange membrane of this example is almost the same as that of Example 15, except for the different ratio of raw materials in step 1). Specifically, carbazole monomer, dimethylfluorene, and trifluoropyruvic acid methyl ester monomer were dissolved in dichloromethane to obtain a mixed liquid system, and the solid content of the mixed liquid system was 15 wt.%. Trifluoromethanesulfonic acid as a catalyst was slowly added dropwise to the mixed liquid system while stirring at 0°C, and the carbazole monomer, dimethylfluorene, trifluoropyruvic acid methyl ester monomer, and catalyst were mixed. The molar ratio is 2 :1:3:50.

[0090] Example 17 The preparation method of the polymer and proton exchange membrane of this example is almost the same as that of Example 15, except for the different ratio of raw materials in step 1). Specifically, carbazole monomer, phenanthrene, and trifluoroacetophenone monomer were dissolved in dichloromethane to obtain a mixed liquid system, and the solid content of the mixed liquid system was 10 wt.%. Trifluoroacetic acid and trifluoromethanesulfonic acid were slowly added dropwise as catalysts to the mixed liquid system while stirring at 0°C, and the carbazole monomer, phenanthrene, trifluoroacetophenone monomer, trifluoroacetic acid, and trifluoromethanesulfonic acid were mixed. The molar ratio is 5 :1:6:12:80.

[0091] Example 18 The preparation method of the polymer and proton exchange membrane of this example is almost the same as that of Example 15, except for the different ratio of raw materials in step 1). Specifically, carbazole monomer, 1,1'-biphenyl-2,2'-diol, and 3,4-hexanedione monomer were dissolved in dichloromethane to obtain a mixed liquid system, and the solid content of the mixed liquid system was 10 wt.%. Trifluoromethanesulfonic acid as a catalyst was slowly added dropwise to the mixed liquid system while stirring at 0°C, and the carbazole monomer, 1,1'-biphenyl-2,2'-diol, 3,4-hexanedione monomer, and catalyst were mixed. The molar ratio is 2 :1:3:30.

[0092] Example 19 The preparation method of the polymer and proton exchange membrane of this example is almost the same as that of Example 1, except that a part of step 1) and a part of step 2) are different from those of Example 1. Specifically, 1) Carbazole monomer and butanedione monomer were dissolved in dichloromethane to obtain a mixed solution, and the solid content of the solution was 10 wt.%. Trifluoroacetic acid as a catalyst was slowly added dropwise to the mixed solution while stirring at 0°C, and the molar ratio of carbazole monomer, butanedione monomer, and catalyst was 1:1:15. The rest was the same as in step 1) of Example 1. 2) The purified copolymer is dissolved in dimethyl sulfoxide. When it is completely dissolved, anhydrous potassium carbonate, sodium 5-bromo-1-pentanesulfonate monomer, and hydrophilic monomer 1-bromo-2-(2-methoxyethoxy)ethane are added, and the copolymer, anhydrous potassium carbonate, sodium 5-bromo-1-pentanesulfonate monomer, and hydrophilic monomer 1-bromo-2-(2-methoxyethoxy)ethane are mixed. The molar ratio is 4 The ratio was 4:3:1, and the other steps were the same as in step 2) of Example 1.

[0093] The polymer prepared in this example was characterized by nuclear magnetic resonance hydrogen spectroscopy. Figure 1 shows the main chain of the polymer of Example 19. 1 As can be seen from Figure 1, the main chain of the polymer 1 H NMR data is 1 H NMR (400MHz, CDCl3) δ 11.6 (s,1H),7.96 (d,J=1.7Hz,2H),7.31 (d,J=4.1Hz,4H),2.17 (s,3H),2.05 (s,3H).

[0094] Example 20 The preparation method of the polymer and proton exchange membrane of this example is almost the same as that of Example 1, except that a part of step 2) is different from that of Example 1. Specifically, The purified polycarbazole-biphenyl-butanedione copolymer was dissolved in dimethyl sulfoxide. When it was completely dissolved, anhydrous potassium carbonate and sodium 3-bromo-1-propanesulfonate monomer were added to the copolymer. The copolymer, anhydrous potassium carbonate, and sodium 3-bromo-1-propanesulfonate monomer were then mixed. The molar ratio is 5 The ratio was 2:4, and the other steps were the same as in step 2) of Example 1.

[0095] Comparative Example 1 The method for preparing the proton exchange membrane of this comparative example is almost the same as that of Example 1, except that the raw materials in step 2) are different. Specifically, the copolymer prepared in step 1) of Example 1 is dissolved in dimethyl sulfoxide. After complete dissolution, anhydrous potassium carbonate, sodium 3-bromo-1-propanesulfonate monomer, and bromooctane monomer are added to prepare a mixture of the copolymer, anhydrous potassium carbonate, sodium 3-bromo-1-propanesulfonate monomer, and bromooctane. The molar ratio of the monomers is 5 The other steps were the same as in Example 1.

[0096] Comparative Example 2 The preparation method of the polymer and proton exchange membrane of this comparative example is almost the same as that of Example 19, except that part of step 1) and part of step 2) are different from those of Example 1. Specifically, 1) Isatin monomer and biphenyl monomer were dissolved in dichloromethane to obtain a mixed liquid system. The solid content of the mixed liquid system was 10 wt.%. Trifluoromethanesulfonic acid was slowly added dropwise to the mixed liquid system as a catalyst while stirring at 0°C. an isatin monomer, a biphenyl monomer, The molar ratio of the catalyst was 1:1:15. The other steps were the same as in step 1) of Example 19. 2) The purified copolymer is dissolved in dimethyl sulfoxide. When it is completely dissolved, anhydrous potassium carbonate and 5-bromo-1-pentanesulfonic acid sodium monomer are added to the copolymer. The copolymer, anhydrous potassium carbonate, and 5-bromo-1-pentanesulfonic acid sodium monomer are mixed. The molar ratio is 4 The ratio was 4:3, and the other steps were the same as in step 2) of Example 19.

[0097] Test Example 1. The proton exchange membranes in the above examples and comparative examples were tested for ionic conductivity according to the following method, and the results are shown in Table 1.

[0098] The test was performed using an AC impedance method with two electrodes on an electrochemical workstation at a test frequency of 1 Hz to 1 MHz at 80°C and 100% relative humidity.

[0099] 2. The proton exchange membranes in the above examples and comparative examples were subjected to tensile strength tests according to the following method. The results are shown in Table 1.

[0100] The test was carried out using a universal material testing machine.

[0101] 3. The proton exchange membranes in the above examples and comparative examples were tested for water absorption according to the following method, and the results are shown in Table 1.

[0102] The test method is to weigh the dry membrane and measure the weight of the membrane. 乾 The membrane was then thoroughly immersed in deionized water for 24 hours, and then taken out. The water droplets on the surface were quickly absorbed with filter paper, and the membrane was weighed to determine its wet weight W 湿 This procedure was repeated three times. The water absorption rate of the membrane was calculated as follows: 湿 -W 乾 ) / W 乾 ×100%.

[0103] [Table 1]

[0104] As is clear from Table 1, the proton exchange membrane containing the polymer of the present invention is superior in ionic conductivity, water absorption rate, and tensile strength compared to the comparative example.

[0105] 4. The proton exchange membranes of Examples 1 and 2 and Comparative Examples 1 and 2 were assembled into membrane electrodes for fuel cells, and the performance of the fuel cells was tested. The results are shown in Table 2.

[0106] [Table 2]

[0107] As is clear from Table 2, Examples 1 and 2 have higher maximum power densities than the comparative example, which indicates that the proton exchange membrane of the present invention has stronger proton conduction ability and excellent ionic conductivity.

[0108] 5. The proton exchange membranes of Examples 1 and 2 and Comparative Examples 1 and 2 were assembled into electrolytic water tanks and electrolyzed water performance tests were conducted. The test method involved preparing the membranes as membrane electrodes, assembling the membrane electrodes into a single electrolytic water tank, applying different currents to both ends of the tank, recording the current densities and corresponding voltages at different currents, and plotting current density-voltage curves. Figure 2 compares the current density-voltage curves of the proton exchange membranes of Examples 1 and 2 and Comparative Examples 1 and 2 assembled into electrolytic water tanks. As is clear from Figure 2, compared with the Comparative Examples, the electrolytic water tanks assembled in the Examples had lower electrolytic cell voltages and lower energy consumption at the same current density, indicating that the proton exchange membranes of the present invention have lower internal resistance and higher ionic conductivity.

[0109] Finally, it should be noted that the above embodiments are intended to illustrate the technical solutions of the present application, but are not intended to limit the same. Although the present application will be described in detail with reference to the above embodiments, those skilled in the art may still modify the technical solutions described in the above embodiments or make equivalent substitutions for some or all of the technical features thereof, and such modifications or substitutions shall not cause the essence of the corresponding technical solutions to depart from the scope of the technical solutions of the embodiments of the present application.

[0110] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority from a Chinese patent application bearing application number 202211353545.1 and entitled "Polymer and its preparation method and use" filed with the State Intellectual Property Office of the People's Republic of China on November 1, 2022, the entire contents of which are incorporated herein by reference.

Claims

1. A polymer having a structure represented by formula 1: 【Chemical 1】 In Formula 1, M is derived from a ketone monomer, Ar is derived from an aromatic ring conjugated monomer, and X ＋ is a monovalent cation, x １ , y １ , and z １ are the mole fractions of each block, and 0<x １ ≦1, 0≦z １ < 1, 0 ≤ y １ <1, x １ +y １ +z １ = 1, n is an integer from 1 to 6, and m １ is an integer from 0 to 6, and m ２ is an integer from 1 to 8.

2. X ＋ Is H ＋ 2. The polymer of claim 1, wherein:

3. 3. The polymer according to claim 1, wherein the ketone monomer is at least one selected from the group consisting of compounds represented by the following formula: 【Chemistry 2】 In the formula, p1 and p2 are each independently an integer of 0 to 10, k is an integer of 1 to 6, q is an integer of 0 to 5, and R １ ~R ５ are each independently selected from hydrogen, fluorine, and methyl.

4. The polymer according to claim 1 or 2, wherein the aromatic ring conjugated monomer is at least one selected from compounds represented by the following formula: 【Chemistry 3】 In the formula, m is an integer from 0 to 3, j is an integer from 1 to 6, and R ６ -R １７ are each independently selected from hydrogen, substituted or unsubstituted C1-C18 alkyl, substituted or unsubstituted C2-C18 alkenyl, and substituted or unsubstituted C2-C18 alkynyl; R １８ is selected from C1-C18 alkyl, C2-C18 alkenyl, and C2-C18 alkynyl; R １９ -R ２０ are each independently selected from hydrogen, fluorine, and methyl.

5. The polymer is The polymer is prepared by a method comprising the steps of: reacting a raw material system containing a polymer precursor, a hydrophilic unit, and a sulfonate in the presence of an acid-binding agent to obtain the polymer; The polymer according to any one of claims 1 to 4, wherein the polymer precursor has a structure of the following formula 1a, and the hydrophilic unit has a structure of the following formula 1b: 【Chemistry 4】 In Formula 1a, x and y are the mole fractions of each block, respectively, and 0<x≦1, x+y=1; R ０ is selected from hydrogen or tert-butoxycarbonyl, m １ is an integer from 0 to 6, and m ２ is an integer from 1 to 8.

6. The polymer according to claim 5, wherein the hydrophilic unit is any one selected from the group consisting of 3-bromopropyl methyl ether, 1-bromo-2-(2-methoxyethoxy)ethane, diethylene glycol-2-bromoethyl methyl ether, and 1-bromo-5-methoxypentane.

7. A method for preparing the polymer of any one of claims 1 to 6, comprising the steps of: The method includes a step of reacting a raw material system containing a polymer precursor, a hydrophilic unit, and a sulfonate in the presence of an acid binder to obtain the polymer, A method for preparing a polymer, wherein the polymer precursor has the structure of Formula 1a and the hydrophilic unit has the structure of Formula 1b. 【Chemistry 5】 In Formula 1a, x and y are the mole fractions of each block, respectively, and 0<x≦1, x+y=1; R ０ is selected from hydrogen or tert-butoxycarbonyl, m １ is an integer from 0 to 6, and m ２ is an integer from 1 to 8.

8. The polymer precursor is The polymer precursor is prepared by a method comprising the steps of: reacting a mixed liquid system containing a ketone monomer, an aromatic ring conjugated monomer, and a carbazole monomer in the presence of a catalyst to obtain the polymer precursor; The preparation method according to claim 7, wherein the catalyst is at least one selected from the group consisting of trifluoroacetic acid, trifluoromethanesulfonic acid, and methanesulfonic acid.

9. The method according to claim 7 or 8, wherein the sulfonate is any one selected from the group consisting of sodium 3-bromo-1-propanesulfonate, sodium 4-bromo-1-butanesulfonate, sodium 5-bromo-1-pentanesulfonate, sodium 6-bromo-1-hexanesulfonate, sodium 7-bromo-1-heptanesulfonate, sodium 8-bromo-1-octanesulfonate, and sodium 9-bromo-1-nonanesulfonate.

10. A cation exchange membrane, the composition of which comprises the polymer according to any one of claims 1 to 6.

11. A fuel cell comprising the cation exchange membrane of claim 10.

12. An electrolyzed water device comprising the cation exchange membrane according to claim 10.

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