Anion-exchange polymer and preparation method therefor, and anion-exchange membrane

Abstract

Provided in the present application are an anion-exchange polymer and a preparation method therefor, and an anion-exchange membrane. The anion-exchange polymer comprises a segment I and / or a segment II. The structural formula of the segment I is as shown in Formula I, and the structural formula of the segment II is as shown in Formula II, wherein A is a nitrogen-containing heterocyclic ketone, Ar1 is a first aryl structural unit; Ar2 is a second aryl structural unit; and M- is a trifluoroacetate ion and / or a p-toluenesulfonate ion. The anion-exchange polymer of the present application has low toxicity to a catalyst, and thus exhibits good electrochemical performance.

Description

An anion exchange polymer, its preparation method, and anion exchange membrane

[0001] This application claims priority to Chinese Patent Application No. 2025103077728, filed with the Chinese Patent Office on March 14, 2025, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of battery materials technology, specifically to an anion exchange polymer, its preparation method, and an anion exchange membrane. Background Technology

[0003] Anion exchange membranes consist of a polymer backbone and anion exchange groups. The polymer backbone provides the membrane material with mechanical strength and stability, while the anion exchange groups provide the membrane material with hydroxide ion conductivity. Anion exchange membranes play a crucial role in hydrogen production and utilization, especially showing great application potential in water electrolysis for hydrogen production and fuel cells.

[0004] Anion exchange membranes are prepared from anion exchange polymers, which are generally obtained through a two-step process of superacid polymerization and quaternization. Quaternization refers to the process by which the polymerization product forms a polymer with a quaternary ammonium salt under specific quaternizing reagents and reaction conditions. Traditional quaternizing reagents are halogenated hydrocarbons, primarily iodomethane, and the resulting anion is a halide ion. However, most halide ions have varying degrees of poisoning effects on catalysts and may directly interact with active sites on the catalyst surface, leading to system deactivation.

[0005] CN116425959A discloses an anion exchange polymer, anion exchange membrane, preparation method and application thereof. The anion exchange polymer is a cross-linked polymer with an aryl group and a piperidine cationic structure in the main chain. Side chains with cationic groups are grafted onto the nitrogen of the piperidine cationic structure in the main chain, and the side chains form a cross-linked network structure through cross-linking.

[0006] CN113307966 discloses a copolymer containing tetramethylpiperidine oxide quaternary ammonium salt, its preparation method, and its application. First, a halogenated alkylated polymer is prepared. Then, using the halogen at the end of the alkyl chain as the reactive site, cationic groups with stable nitroxide radicals are functionalized by grafting onto the polymer through an atom transfer radical coupling reaction. The cyclic piperidine group can enhance the steric hindrance effect of the cation and improve the stability of the cationic functional group. At the same time, the presence of the six-membered ring of nitroxide radical can reduce the water absorption and swelling rate of the membrane. After casting and ion exchange processes, an alkaline anion exchange membrane material with high alkali resistance, high ion conductivity, and low water absorption and swelling rate can be obtained. Technical issues

[0007] The anion exchange polymer prepared by the above method has a high degree of poisoning to the catalyst, resulting in poor electrochemical performance and reduced service life. Technical solutions

[0008] This application provides an anion exchange polymer, its preparation method, and an anion exchange membrane. The anion exchange polymer described in this application exhibits excellent electrochemical performance due to its low toxicity to catalysts.

[0009] In a first aspect, this application provides an anion exchange polymer, the anion exchange polymer comprising segment I and / or segment II, wherein the structural formula of segment I is as follows: The structural formula of the chain segment II is as follows: In this denoted molecule, A is a nitrogen-containing heterocyclic ketone, Ar1 is the first aryl structural unit, Ar2 is the second aryl structural unit, M- is a trifluoroacetic acid ion and / or a p-toluenesulfonate ion, x is 0.5~0.9, and y is 1-x.

[0010] Secondly, this application provides a method for preparing the anion exchange polymer as described in the first aspect, the method comprising the following steps:

[0011] (1) The monomer of segment I and / or the monomer of segment II, the nitrogen-containing heterocyclic ketone and the first solvent are mixed to obtain a first mixed solution, and a superacid is added to the first mixed solution to carry out a polymerization reaction to obtain a polymer precursor;

[0012] (2) The polymer precursor, quaternizing agent, acid-binding agent and second solvent are mixed to obtain a second mixed solution, and the second mixed solution is subjected to a functionalization reaction to obtain the anion exchange polymer.

[0013] Thirdly, this application provides an anion exchange membrane, which is prepared by dissolving the anion exchange polymer as described in the first aspect in a third solvent, followed by coating and drying.

[0014] Compared with related technologies, this application has the following advantages:

[0015] The anion exchange polymer described in this application exhibits excellent electrochemical performance due to its low toxicity to catalysts.

[0016] After reading and understanding the detailed description, other aspects can be understood. Specific embodiments of the present invention

[0017] In a first aspect, this application provides an anion exchange polymer, the anion exchange polymer comprising segment I and / or segment II, wherein the structural formula of segment I is as follows: The structural formula of the chain segment II is as follows: In this denoted molecule, A is a nitrogen-containing heterocyclic ketone, Ar1 is the first aryl structural unit, Ar2 is the second aryl structural unit, M- is a trifluoroacetic acid ion and / or a p-toluenesulfonate ion, x is 0.5~0.9, and y is 1-x.

[0018] Due to their special structure, segments I and / or II in the anion exchange polymer described in this application exhibit low electronegativity and relatively weak interaction with metal active sites, thus having a smaller poisoning effect on the catalyst.

[0019] Optionally, with the total molar amount of the chain segments in the anion exchange polymer being 100%, the molar percentage of the chain segment I is 85% to 95%, for example: 85%, 88%, 90%, 92% or 95%, etc., not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0020] Optionally, with the total molar amount of the chain segments in the anion exchange polymer being 100%, the molar percentage of the chain segment II is 5% to 15%, for example: 5%, 8%, 10%, 12% or 15%, etc., not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0021] Optionally, the nitrogen-containing heterocyclic ketone includes piperidinone and / or quinine cyclic ketone.

[0022] Optionally, the structural formula of the piperidinone is as follows:

[0023] R1 and R2 independently include any one or at least two combinations of methyl, ethyl, propyl, butyl, pentyl, cyclopropyl, cyclopropyl or halogen, with typical but non-limiting combinations including combinations of methyl and ethyl, ethyl and propyl or methyl and halogen, etc.

[0024] Optionally, the structural formula of the quinine cycloketone is as follows: R3 includes any one or a combination of at least two of hydrogen, alkyl, alkenyl, alkynyl, hydroxyl, alkoxy or aryl, with typical but non-limiting combinations including combinations of alkyl and alkenyl, hydroxyl and alkoxy or aryl and alkoxy, etc.

[0025] Optionally, the first aryl structural unit includes any one or a combination of at least two of biphenyl, para-terphenyl, meta-terphenyl, tetraphenyl or 1,2-diphenylethane. Typical but non-limiting combinations include combinations of biphenyl and para-terphenyl, meta-terphenyl and tetraphenyl, or para-terphenyl and meta-terphenyl, etc.

[0026] Optionally, the second aryl structural unit includes any one or a combination of at least two of 1,3,5-triphenylbenzene, triphenylmethane, 9,10-benzophenanthrene, tetraphenylmethane, tripterene, 9,9'-diphenylfluorene, 9,9'-spirobisfluorene, 9,9'-bifluorene, 9,9'-bicarbazole, 4,4-bis(9-carbazole)biphenyl, 2,2'-bi-9,9'-spirobis[9H-fluorene], or triphenylamine. Typical but non-limiting combinations include combinations of 1,3,5-triphenylbenzene and triphenylmethane, combinations of 9,9'-spirobisfluorene and 9,9'-bifluorene, or combinations of 2,2'-bi-9,9'-spirobis[9H-fluorene] and triphenylamine, etc.

[0027] Secondly, this application provides a method for preparing the anion exchange polymer as described in the first aspect, the method comprising the following steps:

[0028] (1) The monomer of segment I and / or the monomer of segment II, the nitrogen-containing heterocyclic ketone and the first solvent are mixed to obtain a first mixed solution, and a superacid is added to the first mixed solution to carry out a polymerization reaction to obtain a polymer precursor;

[0029] (2) The polymer precursor, quaternizing agent, acid-binding agent and second solvent are mixed to obtain a second mixed solution, and the second mixed solution is subjected to a functionalization reaction to obtain the anion exchange polymer.

[0030] Optionally, in step (1), the first solvent includes any one or a combination of at least two of dichloromethane, trichloromethane, chloroform, or tetrahydrofuran.

[0031] Optionally, the total molar ratio of the monomer of segment I and the monomer of segment II in step (1) to the molar ratio of the nitrogen-containing heterocyclic ketone is 1:(1~4), for example: 1:1, 1:1.5, 1:2, 1:3 or 1:4, etc., not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0032] Optionally, the superacid in step (1) includes any one or a combination of at least two of methanesulfonic acid, pentafluoropropionic acid, trifluoroacetic acid, trifluoromethanesulfonic acid or heptafluorobutyric acid. Typical but non-limiting combinations include combinations of methanesulfonic acid and pentafluoropropionic acid, combinations of pentafluoropropionic acid and trifluoroacetic acid, or combinations of trifluoromethanesulfonic acid and heptafluorobutyric acid.

[0033] Optionally, the ambient temperature for adding the superacid in step (1) is -2℃ to 2℃, for example: -2℃, -1℃, 0℃, 1℃ or 2℃, etc., not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0034] Optionally, the polymerization reaction in step (1) includes an oligomerization reaction followed by a polymerization reaction.

[0035] Optionally, the temperature of the oligomerization reaction is 4℃~6℃, for example: 4℃, 4.5℃, 5℃, 5.5℃ or 6℃, etc., not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0036] Optionally, the oligomerization reaction time is 1h to 5h, for example: 1h, 2h, 3h, 4h or 5h, etc., not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0037] Optionally, the temperature of the polymerization reaction is 12℃~18℃, for example: 12℃, 13℃, 14℃, 15℃, 16℃, 17℃ or 18℃, etc., not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0038] Optionally, the time for the polymerization reaction is 1h to 5h, for example: 1h, 2h, 3h, 4h or 5h, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0039] Optionally, after the polymerization reaction described in step (1), the product is subjected to extrusion, washing and drying.

[0040] Optionally, the quaternizing agent in step (2) includes methyl trifluoroacetate and / or methyl p-toluenesulfonate.

[0041] Optionally, the molar ratio of the quaternizing agent to the polymer precursor in step (2) is (1.2~1.8):1, for example: 1.2:1, 1.4:1, 1.5:1, 1.6:1 or 1.8:1, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0042] Optionally, the acid-binding agent in step (2) includes any one or a combination of at least two of potassium carbonate, sodium carbonate, triethylamine, diethanolamine or ethylenediamine. Typical but non-limiting combinations include combinations of potassium carbonate and sodium carbonate, combinations of sodium carbonate and triethylamine or combinations of triethylamine and diethanolamine, etc.

[0043] Optionally, the molar ratio of the acid-binding agent to the polymer precursor in step (2) is (1.1~1.3):1, for example: 1.1:1, 1.15:1, 1.2:1, 1.25:1 or 1.3:1, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0044] Optionally, the second solvent in step (2) includes any one or a combination of at least two of dimethyl sulfoxide, tetrahydrofuran, N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, or acetonitrile. Typical but non-limiting combinations include a combination of dimethyl sulfoxide and tetrahydrofuran, a combination of N,N-dimethylacetamide and acetonitrile, or a combination of N-methyl-2-pyrrolidone and N,N-dimethylformamide, etc.

[0045] Optionally, the temperature of the functionalization reaction in step (2) is 30℃~100℃, for example: 30℃, 50℃, 60℃, 80℃ or 100℃, etc., not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0046] Optionally, the functionalization reaction time in step (2) is 10h to 20h, for example: 10h, 12h, 15h, 18h or 20h, etc., not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0047] Thirdly, this application provides an anion exchange membrane, which is prepared by dissolving the anion exchange polymer as described in the first aspect in a third solvent, followed by coating and drying.

[0048] Optionally, the third solvent includes any one or a combination of at least two of ethanol, ethyl acetate, ethylene glycol, diethyl ether, tetrahydrofuran, acetone, or water. Typical but non-limiting combinations include combinations of ethyl acetate and ethylene glycol, ethylene glycol and diethyl ether, or tetrahydrofuran and acetone.

[0049] Optionally, the drying temperature is 50℃~70℃, for example: 50℃, 55℃, 60℃, 65℃ or 70℃, etc., not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0050] Optionally, the drying time is 5h to 10h, for example: 5h, 6h, 7h, 8h, 9h or 10h, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0051] The technical solution of this application will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely to help understand this application and should not be regarded as specific limitations on this application.

[0052] Example 1

[0053] This embodiment provides an anion exchange polymer, and the preparation method of the anion exchange polymer is as follows:

[0054] (1) 0.135 mol of terphenyl and 0.36 mol of N-methyl-4-piperidinone were mixed in 100 mL of dichloromethane. Trifluoroacetic acid (22.8 mL) and trifluoromethanesulfonic acid (240 mL) were added dropwise to the solution at 0 °C. After the addition was complete, an oligomerization reaction was carried out at 5 °C for 3 h, and a high-polymerization reaction was carried out at 15 °C for 3 h. After the reaction was completed, the polymer was extruded into pure water, filtered, washed with pure water, and dried to obtain the polymer precursor.

[0055] (2) The polymer product (0.1 mol) obtained in step (1), the acid-binding agent triethylamine (0.12 mol), and the quaternizing agent methyl trifluoroacetate (0.15 mol) were mixed with dimethyl sulfoxide (200 mL) and reacted at 80 °C for 15 h. The product after the reaction was completed was precipitated with ethyl acetate, filtered, washed with ethyl acetate, and dried to obtain the anion exchange polymer. The structural formula of the anion exchange polymer is as follows: .

[0056] Example 2

[0057] This embodiment provides an anion exchange polymer, and the preparation method of the anion exchange polymer is as follows:

[0058] (1) 0.135 mol of terphenyl and 0.36 mol of 3-quinone were mixed in 100 mL of dichloromethane. Trifluoroacetic acid (22.8 mL) and trifluoromethanesulfonic acid (240 mL) were added dropwise to the solution at 0 °C. After the addition was complete, an oligomerization reaction was carried out at 5 °C for 3 h, and a high-polymerization reaction was carried out at 15 °C for 4 h. After the reaction was completed, the polymer was extruded into pure water, filtered, washed with pure water, and dried to obtain the polymer precursor.

[0059] (2) The polymer product (0.1 mol) obtained in step (1), the acid-binding agent triethylamine (0.11 mol), and the quaternizing agent methyl trifluoroacetate (0.15 mol) were mixed with dimethyl sulfoxide (200 mL) and reacted at 80 °C for 15 h. The product after the reaction was completed was precipitated with ethyl acetate, filtered, washed with ethyl acetate, and dried to obtain the anion exchange polymer. The structural formula of the anion exchange polymer is as follows: .

[0060] Example 3

[0061] This embodiment provides an anion exchange polymer, and the preparation method of the anion exchange polymer is as follows:

[0062] (1) 0.091 mol of terphenyl, 0.039 mol of biphenyl, and 0.36 mol of N-methyl-4-piperidinone were mixed in 100 mL of dichloromethane. Trifluoroacetic acid (22.8 mL) and trifluoromethanesulfonic acid (240 mL) were added dropwise to the solution at 0 °C. After the addition was complete, an oligomerization reaction was carried out at 5 °C for 2 h, and a high-polymerization reaction was carried out at 15 °C for 4 h. After the reaction was completed, the polymer was extruded into pure water, filtered, washed with pure water, and dried to obtain the polymer precursor.

[0063] (2) The polymer product (0.1 mol) obtained in step (1), the acid-binding agent triethylamine (0.13 mol), and the quaternizing agent methyl p-toluenesulfonate (0.15 mol) were mixed with dimethyl sulfoxide (200 mL) and reacted at 80 °C for 15 h. The product after the reaction was completed was precipitated with ethyl acetate, filtered, washed with ethyl acetate, and dried to obtain the anion exchange polymer. The structural formula of the anion exchange polymer is as follows: .

[0064] Example 4

[0065] This embodiment provides an anion exchange polymer, and the preparation method of the anion exchange polymer is as follows:

[0066] (1) 0.155 mol of terphenyl, 0.015 mol of triphenylmethane, and 1.95 mol of N-methyl-4-piperidinone were mixed with 100 mL of dichloromethane. Trifluoroacetic acid (22.8 mL) and trifluoromethanesulfonic acid (240 mL) were added dropwise to the solution at 0 °C. After the addition was complete, an oligomerization reaction was carried out at 5 °C for 3 h, followed by a high-polymerization reaction at 15 °C for 5 h. After the reaction was completed, the polymer was extruded into pure water, filtered, washed with pure water, and dried to obtain the polymer precursor.

[0067] (2) The polymer product (0.1 mol) obtained in step (1), the acid-binding agent triethylamine (0.12 mol), and the quaternizing agent methyl trifluoroacetate (0.15 mol) were mixed in dimethyl sulfoxide (200 mL) and reacted at 80 °C for 15 h. The product after the reaction was completed was precipitated with ethyl acetate, filtered, washed with ethyl acetate, and dried to obtain the anion exchange polymer. The structural formula of the anion exchange polymer is as follows: and The molar percentage of chain segment I is 88%, and the molar percentage of chain segment II is 12%.

[0068] Example 5

[0069] The only difference between this embodiment and Example 4 is that the amount of acid-binding agent added is 0.1 mol, while the other conditions and parameters are exactly the same as in Example 1.

[0070] Example 6

[0071] The only difference between this embodiment and Example 4 is that the amount of acid-binding agent added is 0.15 mol, while the other conditions and parameters are exactly the same as in Example 1.

[0072] Example 7

[0073] The only difference between this embodiment and embodiment 4 is that the molar percentage of chain segment I is 98% and the molar percentage of chain segment II is 2%. All other conditions and parameters are exactly the same as in embodiment 1.

[0074] Example 8

[0075] The only difference between this embodiment and embodiment 4 is that the molar percentage of chain segment I is 80% and the molar percentage of chain segment II is 20%. All other conditions and parameters are exactly the same as in embodiment 1.

[0076] Comparative Example 1

[0077] The only difference between this comparative example and Example 1 is that the quaternizing agent methyl trifluoroacetate is replaced with an equal amount of iodomethane; all other conditions and parameters are exactly the same as in Example 1.

[0078] Comparative Example 2

[0079] The only difference between this comparative example and Example 2 is that the quaternizing agent methyl trifluoroacetate is replaced with an equal amount of iodomethane; all other conditions and parameters are exactly the same as in Example 1.

[0080] Comparative Example 3

[0081] The only difference between this comparative example and Example 3 is that the quaternizing agent methyl trifluoroacetate is replaced with an equal amount of bromopropane; all other conditions and parameters are exactly the same as in Example 1.

[0082] Comparative Example 4

[0083] The only difference between this comparative example and Example 4 is that the quaternizing agent methyl trifluoroacetate is replaced with an equal amount of bromopropane; all other conditions and parameters are exactly the same as in Example 1.

[0084] Performance testing:

[0085] The anion exchange polymers prepared in the examples and comparative examples were dissolved in dimethyl sulfoxide to obtain homogeneous solutions. These homogeneous solutions were then poured onto a flatbed coating machine and dried at 60°C for 8 hours to obtain the final anion exchange membranes. The anion exchange membranes were then subjected to the following tests:

[0086] 1. Mechanical performance testing

[0087] Test method: Refer to GB / T1040.3 Determination of tensile properties of plastics - Part 3: Test conditions for films and sheets (ISO527-3:1995, IDT)

[0088] Under constant temperature and humidity conditions of 23℃±2℃ and 50%±10% relative humidity, the thickness and width of the sample were measured. When placing the sample in the test fixture, different tensile speeds, selected within the range of 50mm / min to 200mm / min, can be used to determine the tensile strength and elongation at break. Each tensile speed should be applied to a separate specimen. After the sample breaks, the corresponding load value is recorded.

[0089] a. Tensile strength: The ratio of the maximum load that a resin-made membrane can withstand when it breaks under pure tensile force to the width of the membrane material being stretched. It is divided into transverse and longitudinal tensile strength and is used to evaluate the mechanical strength of the membrane.

[0090] b. Elongation at break: The ratio of the distance between two points at break to the original length of a resin-made membrane under the maximum load it withstands before fracture. It represents the maximum deformation an alkaline membrane can withstand before breaking and is used to evaluate the membrane's flexibility.

[0091] 2. Pure water swelling performance test

[0092] Test method: Anion exchange resin was prepared into a membrane, which was cut into 1cm×4cm pieces and placed in 1M KOH solution with the alkali changed three times. The swelling performance was then tested in deionized water at 80℃.

[0093] 3. Electrolysis of water application test

[0094] The membrane was fabricated into a membrane electrode with an active area of ​​80 cm². 2 The cathode nickel-molybdenum alloy loading is 1.0 mg / cm³. 2 The nickel ferrite loading at the anode is 1.2 mg / cm³. 2 Then, they were assembled into a single-cell electrolyzer. Under operating conditions of 60℃, the polarization performance, sheet resistivity, and decay rate of the membrane within 1000 hours were tested (the decay rate was calculated based on a test run of 0.5 A / cm before and after different stability test procedures). 2 After running for 20 hours, the two values ​​were integrated, and the difference between them was divided by the value obtained after integrating the initial stability data (this is the decay rate). The polarization performance is 1.0 A / cm. 2 The groove pressure was measured. The test results are shown in Table 1:

[0095]

[0096] As shown in Table 1, and based on Examples 1-4, the anion exchange polymer described in this application exhibits a tensile strength of over 36 MPa, an elongation at break of less than 34%, a swelling ratio of less than 19.9%, and a tensile strength of 1.0 A / cm². 2 The cell voltage can reach below 1.81V, and the surface resistivity can reach 212mΩ / cm. 2 Within 1000 hours, the decay rate can reach within 3.9%. For different main chain structures, the electrochemical performance of the membrane material after quaternization with methyl trifluoroacetate is better than that of the membrane material after quaternization with iodomethane.

[0097] A comparison of Examples 4 and 5-6 shows that the amount of acid-binding agent added during the preparation of the anion exchange polymer described in this application affects its performance. Controlling the molar ratio of acid-binding agent to polymer precursor at (1.1~1.3):1 yields anion exchange polymer with better performance. If the amount of acid-binding agent added is too large, it leads to excessive swelling, resulting in superior polarization performance, but high swelling may reduce electrochemical stability. If the amount of acid-binding agent added is too small, the swelling decreases, and the polarization performance, i.e., the electrochemical performance, decreases.

[0098] A comparison of Examples 4 and 7-8 shows that the molar ratio of segment I and segment II in the anion exchange polymer described in this application affects its performance. Controlling the molar ratio of segment I to 85%~95% and the molar ratio of segment II to 5%~15% results in a better-performing anion exchange polymer. If the molar ratio of segment I is too large, there may be solubility defects. However, if it is soluble, it exhibits advantages of low swelling and high ionic conductivity. If the molar ratio of segment I is too small, the improvement in dimensional stability and electrochemical performance is not significant.

[0099] Comparisons between Example 1 and Comparative Example 1, Example 2 and Comparative Example 2, Example 3 and Comparative Example 3, and Example 4 and Comparative Example 4 show that the use of ester-based quaternizing agents instead of conventional halogenated hydrocarbon quaternizing agents in this application has no significant impact on the mechanical properties and dimensional stability of the final product. Comparing polarization performance and sheet resistivity data, the examples show a certain advantage over the comparative examples, with a reduction in polarization performance of nearly 50 mV. This is attributed to the difference in the influence of anions on the catalytic layer after quaternization. The anionic form of the membrane material corresponding to the examples has a relatively weaker interaction with the metal active sites, resulting in less poisoning of the catalyst and thus exhibiting superior electrochemical performance. Comparing the decay rate data of different samples within 1000 h, it can be significantly found that, under the same material main chain structure, the membrane material corresponding to the examples exhibits superior application stability, further demonstrating the significant advantage of materials corresponding to ester-based quaternization.

Claims

1. An anion exchange polymer comprising segment I and / or segment II, wherein the structural formula of segment I is as follows: The structural formula of the chain segment II is as follows: ,in, A is a nitrogen-containing heterocyclic ketone, Ar1 is the first aryl structural unit, Ar2 is the second aryl structural unit, M- is trifluoroacetic acid ion and / or p-toluenesulfonate ion, x is 0.5~0.9, and y=1-x.

2. The anion exchange polymer as described in claim 1, wherein, With the total molar amount of chain segments in the anion exchange polymer being 100%, the molar percentage of chain segment I is 85% to 95%.

3. The anion exchange polymer as described in claim 1 or 2, wherein, With the total molar amount of the chain segments in the anion exchange polymer being 100%, the molar percentage of chain segment II is 5% to 15%.

4. The anion exchange polymer according to any one of claims 1-3, wherein, The nitrogen-containing heterocyclic ketones include piperidinones and / or quinine cyclic ketones.

5. The anion exchange polymer as described in claim 4, wherein, The structural formula of the piperidinone is: R1 and R2 independently include any one or a combination of at least two of methyl, ethyl, propyl, butyl, pentyl, cyclopropyl, cyclopropyl or halogen.

6. The anion exchange polymer as described in claim 4, wherein, The structural formula of the quinine cycloketone is as follows: R3 includes any one or a combination of at least two of hydrogen, alkyl, alkenyl, alkynyl, hydroxyl, alkoxy or aryl, wherein the number of carbon atoms in R3 is 0 to 20.

7. The anion exchange polymer according to any one of claims 1-6, wherein, The first aryl structural unit includes any one or a combination of at least two of biphenyl, p-terphenyl, m-terphenyl, tetraphenyl or 1,2-diphenylethane; Optionally, the second aryl structural unit includes any one or a combination of at least two of the following: 1,3,5-triphenylbenzene, triphenylmethane, 9,10-benzophenanthrene, tetraphenylmethane, triphenylene, 9,9'-diphenylfluorene, 9,9'-spirobifluorene, 9,9'-bifluorene, 9,9'-bicarbazole, 4,4-bis(9-carbazole)biphenyl, 2,2'-bi-9,9'-spirobi[9H-fluorene], or triphenylamine.

8. A method for preparing the anion exchange polymer according to any one of claims 1-7, comprising the following steps: (1) The monomer of segment I and / or the monomer of segment II, the nitrogen-containing heterocyclic ketone and the first solvent are mixed to obtain a first mixed solution, and a superacid is added to the first mixed solution to carry out a polymerization reaction to obtain a polymer precursor; (2) The polymer precursor, quaternizing agent, acid-binding agent and second solvent are mixed to obtain a second mixed solution, and the second mixed solution is subjected to a functionalization reaction to obtain the anion exchange polymer.

9. The preparation method according to claim 8, wherein, Step (1) The first solvent includes any one or a combination of at least two of dichloromethane, trichloromethane, chloroform or tetrahydrofuran.

10. The preparation method according to claim 8 or 9, wherein, In step (1), the total molar amount of monomers of segment I and segment II is in a molar ratio of 1:(1~4) to the nitrogen-containing heterocyclic ketone.

11. The preparation method according to any one of claims 8-10, wherein, The superacid in step (1) includes any one or a combination of at least two of the following: methanesulfonic acid, pentafluoropropionic acid, trifluoroacetic acid, trifluoromethanesulfonic acid, or heptafluorobutyric acid.

12. The preparation method according to any one of claims 8-11, wherein, The ambient temperature for adding the superacid in step (1) is -2℃ to 2℃; Optionally, the polymerization reaction in step (1) includes an oligomerization reaction followed by a polymerization reaction; Optionally, the temperature of the oligomerization reaction is 4°C to 6°C; Optionally, the oligomerization reaction takes 1 to 5 hours. Optionally, the polymerization reaction is carried out at a temperature of 12°C to 18°C. Optionally, the polymerization reaction time is 1 hour to 5 hours; Optionally, after the polymerization reaction described in step (1), the product is subjected to extrusion, washing and drying.

13. The preparation method according to any one of claims 8-12, wherein, The quaternizing agent in step (2) includes methyl trifluoroacetate and / or methyl p-toluenesulfonate; Optionally, the molar ratio of the quaternizing agent to the polymer precursor in step (2) is (1.2~1.8):1; Optionally, the acid-binding agent in step (2) includes any one or a combination of at least two of potassium carbonate, sodium carbonate, triethylamine, diethanolamine or ethylenediamine; Optionally, the molar ratio of the acid-binding agent to the polymer precursor in step (2) is (1.1~1.3):1; Optionally, in step (2), the second solvent includes any one or a combination of at least two of dimethyl sulfoxide, tetrahydrofuran, N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide or acetonitrile; Optionally, the temperature of the functionalization reaction in step (2) is 30℃~100℃; Optionally, the functionalization reaction in step (2) takes 10 to 20 hours.

14. An anion exchange membrane, wherein, The anion exchange membrane is prepared by dissolving the anion exchange polymer as described in any one of claims 1-7 in a third solvent, followed by coating and drying.

15. The anion exchange membrane as described in claim 14, wherein, The third solvent includes any one or a combination of at least two of the following: ethanol, ethyl acetate, ethylene glycol, diethyl ether, tetrahydrofuran, acetone, or water. Optionally, the drying temperature is 50°C to 70°C; Optionally, the drying time is 5 to 10 hours.