A sterically hindered aryl polymer, anion exchange membrane, its preparation method and application

Abstract

This invention discloses a sterically hindered aryl polymer, anion exchange membrane, its preparation method, and its applications, relating to the field of compound synthesis technology. The sterically hindered aryl polymer framework of this invention is free of ether bonds and heteroatoms, endowing the anion exchange membrane with excellent chemical stability, especially in alkaline environments. Furthermore, due to the presence of sterically hindered structural units in the polymer framework, and by introducing a spirodifluorene rigid framework and embedding hydrophobic functional units within the monomer, multi-level ion transport channels are formed with the inherent micropores through synergistic regulation of hydrophilic / hydrophobic microphase separation, significantly improving the ionic conductivity of the anion exchange membrane. These characteristics enable it to meet the application requirements of alkaline fuel cells and alkaline water electrolysis devices. The preparation method of this invention is simple and low-cost, making it very suitable for large-scale industrial production. This not only provides strong support for technological advancements in related fields but also lays a solid foundation for industrial applications.

Description

Technical Field

[0001] This invention relates to the field of compound synthesis technology, and in particular to a sterically hindered aryl polymer, anion exchange membrane, its preparation method and application. Background Technology

[0002] Anion exchange membranes (AEMs), also known as ion-selective permeable membranes, are a type of polymer membrane containing basic active groups that selectively allow anions to pass through. AEMs are a crucial component of anion exchange membrane water electrolysis and anion exchange membrane fuel cell systems. Their function is to conduct hydroxide ions from the cathode to the anode while simultaneously preventing the direct transfer of gases and electrons between the electrodes. AEMs also have wide applications in other new energy electrochemical devices in fields such as electrodialysis, carbon dioxide reduction, and flow batteries.

[0003] Anion exchange membranes (AEMs) consist of a polymer framework, quaternary ammonium active groups, and anions. The quaternary ammonium active groups are located on the polymer framework, while the anions can move freely within these groups. Compared to cation exchange membranes (CEMs), anion exchange membranes not only have more complex preparation routes, but also suffer from low hydroxide conductivity, poor mechanical stability, and poor chemical stability, which are bottlenecks in their development. Furthermore, during operation, the locally formed strongly alkaline environment on the membrane surface can cause degradation and perforation under the influence of hydroxide ions, leading to electrode short circuits and affecting service life. Therefore, the field anticipates the development of novel anion exchange membranes, and synergistically enhancing ionic conductivity, dimensional stability, and alkali resistance is a key challenge for the further development of anion exchange membrane water electrolysis technology and anion exchange membrane fuel cell technology.

[0004] Currently, anion exchange membranes are mainly based on polymer backbones such as polysulfone, polyphenylene ether, and polyetheretherketone. However, polymer backbones containing ether bonds are prone to degradation under alkaline conditions, resulting in poor alkaline stability. Polyaryl 4-piperidine copolymers are a novel type of anion exchange membrane without ether bonds, possessing advantages such as high structural rigidity and ideal dimensional stability. However, existing anion exchange membranes based on polyaryl 4-piperidine polymer backbones suffer from poor conductivity.

[0005] In summary, current commercially available anion exchange membranes still suffer from numerous structural defects, resulting in relatively poor chemical stability and failing to meet the requirements of specific applications. Therefore, developing a novel polymer for preparing anion exchange membranes with both high conductivity and high alkali stability is of great significance for the application and development of anion exchange membranes. Summary of the Invention

[0006] The purpose of this invention is to provide a sterically hindered aryl polymer, anion exchange membrane, its preparation method, and its applications, thereby solving the problems existing in the prior art. The sterically hindered aryl polymer of this invention, with its main chain free of ether bonds and sterically hindered phenyl monomers, can improve the alkali resistance of the anion exchange membrane (AEM). Furthermore, by using a copolymerization strategy with monomers having quaternary ammoniation structures to modify the polymer, hydrophobic functional units are embedded in the monomers. Through the synergistic regulation of hydrophilic / hydrophobic microphase separation, multi-level ion transport channels are formed with the inherent micropores, reducing the water absorption and swelling rate of the AEM, further improving its dimensional stability and ionic conductivity. This invention can be used to prepare anion exchange membranes with high stability.

[0007] To achieve the above objectives, the present invention provides the following solution:

[0008] One of the technical solutions of this invention is to provide a sterically hindered aryl polymer having a general structure as shown in formula (P):

[0009]

[0010] Where Ar is an aryl structural unit; M is a carbonyl structural unit; and the sum of x and y is 100%.

[0011] Furthermore, Ar is selected from one of the copolymer units with the following structures:

[0012]

[0013] The R1 and R2 groups are independently selected from hydrogen atoms and hydrocarbon groups containing 1-20 carbon atoms;

[0014] In this context, * represents a connector.

[0015] Furthermore, M is independently selected from one of the copolymer units with the following structures:

[0016]

[0017] In this context, * represents a connector.

[0018] The second technical solution of the present invention provides a method for preparing the above-mentioned sterically hindered aryl polymer, comprising the following steps:

[0019] Ar group monomer, M corresponding ketone monomer and sterically hindered aryl structure monomer are mixed in a first solvent and reacted in the presence of a first catalyst. The resulting reaction solution is added to a second solvent, the precipitated solid is collected, washed and dried to obtain sterically hindered aryl polymer.

[0020] Further, the molar ratio of the sterically hindered aryl monomer to the Ar monomer is (0-50):(100-50), and is not 0; the molar ratio of the ketone monomer corresponding to M to the sum of the molar amounts of the sterically hindered aryl monomer and the Ar monomer is 1.1:1; the first catalyst includes trifluoroacetic acid (TFA) and / or trifluoromethanesulfonic acid (TFSA).

[0021] Further, the molar ratio of the trifluoroacetic acid to the ketone monomer corresponding to M is (0.5-2):1; the molar ratio of the trifluoromethanesulfonic acid to the ketone monomer corresponding to M is (8-15):1.

[0022] Further, the first solvent includes at least one of dichloromethane, chloroform, or tetrahydrofuran; the second solvent includes at least one of water, ethyl acetate, methanol, ethanol, diethyl ether, tetrahydrofuran, or acetone.

[0023] Furthermore, the volume ratio of the first solvent to the second solvent is 1:(10-30).

[0024] Furthermore, the amount of the ketone monomer corresponding to M is based on the amount of the first solvent added: 5-25 mmol of the ketone monomer corresponding to M is added for every 10-15 mL of the first solvent.

[0025] Furthermore, the reaction temperature is -5 to 15°C, and the reaction time is 0 to 48 hours.

[0026] Furthermore, the washing step includes adding the precipitated polymer to an alkaline solution for washing.

[0027] Furthermore, the alkaline solution includes at least one of K2CO3, KOH, NaOH, and NaHCO3 solutions.

[0028] Furthermore, the drying process includes a vacuum drying step at 70-90°C.

[0029] Among them, the sterically hindered aryl monomer is (2,7-bis(3,5-bis(trifluoromethyl)phenyl)-9,9'-spirofluorene); its preparation method includes the following steps:

[0030] 2,7-Dibromo-9,9'-spirodifluorene and 3,5-bis(trifluoromethyl)phenylboronic acid were mixed in a third solvent and reacted in the presence of a second catalyst to obtain the sterically hindered aryl monomer.

[0031] Furthermore, the molar ratio of 2,7-dibromo-9,9'-spirobifluorene to 3,5-bis(trifluoromethyl)phenylboronic acid is (0-5):1, and is not 0.

[0032] Further, the third solvent is a mixed alkaline solution of at least one aqueous solution of Cs2CO3, K2CO3, Na2CO3, and Li2CO3 with at least one organic solvent of toluene, tetrahydrofuran, and N,N-dimethylformamide.

[0033] Furthermore, the second catalyst includes at least one of Pd(PPh3)4, AsPh3, n-Bu3P, and (MeO)3P.

[0034] Furthermore, the reaction temperature is 60-90℃, and the reaction time is 12-36 hours.

[0035] Furthermore, after the reaction is completed, the process includes adding a quencher to quench the reaction, followed by extraction, drying, separation, and drying. Preferably, the quencher includes methanol and / or ethanol. The drying steps before and after separation include vacuum drying, with a preferred drying temperature of 50-90°C.

[0036] Furthermore, the extraction comprises extraction using a mixed solvent of dichloromethane and water; the preferred molar ratio of dichloromethane to water is (0-10):1, and not 0.

[0037] Furthermore, the separation includes a silica gel column chromatography step. Preferably, the silica gel column chromatography reagent is n-hexane.

[0038] The third technical solution of the present invention provides a sterically hindered aryl quaternized polymer having the general formula structure shown in formula (Q):

[0039]

[0040] Ar is selected from one of the copolymer units with the following structures:

[0041]

[0042] The R1 and R2 groups are independently selected as hydrogen atoms or alkanes containing 1-20 carbon atoms;

[0043] QA independent options are selected from one of the following structures:

[0044]

[0045] In this context, * represents a connector.

[0046] The R3, R4, and R5 groups are independently chosen to be hydrogen atoms or alkanes containing 1-20 carbon atoms;

[0047] The sum of x and y is 100%.

[0048] Fourth technical solution of the present invention: A method for preparing a sterically hindered aryl quaternary ammonium polymer, comprising the following steps:

[0049] The above-mentioned sterically hindered aryl polymer is mixed with a haloalkane or trimethylamine solution in a fourth solvent, and the reaction is carried out in the presence of a third catalyst. The resulting reaction solution is added to a fifth solvent, the precipitated solid is collected, and after drying, a sterically hindered aryl quaternized polymer is obtained, characterized in that...

[0050] Furthermore, the quaternization reaction is carried out at a temperature of 40-60°C for a reaction time of 24-48 hours.

[0051] Furthermore, the third catalyst includes K2CO. 3、 KOH, NaOH.

[0052] Furthermore, the mass ratio of the sterically hindered aryl polymer to the third catalyst is (1-4):1.

[0053] Furthermore, the solid-liquid ratio of the sterically hindered aryl polymer and the haloalkane is 1 g:(2-6) mL.

[0054] Further, the fourth solvent includes at least one of dimethyl sulfoxide, N-methylpyrrolidone, N,N-dimethylformamide, or N,N-dimethylacetamide; the fifth solvent includes at least one of ethyl acetate, methanol, ethanol, acetone, or diethyl ether.

[0055] The solid-liquid ratio of the sterically hindered aryl polymer to the fourth solvent is 1 g:(15-25) mL.

[0056] Furthermore, the volume ratio of the fourth solvent to the fifth solvent is 1:(20-30).

[0057] Furthermore, the drying process includes a vacuum drying step at 70-90°C.

[0058] Fifth technical solution of the present invention: A method for preparing anion exchange membrane, comprising the following steps:

[0059] The above-mentioned sterically hindered aryl quaternary ammonium polymer was mixed with a sixth solvent and cast onto a substrate surface to obtain a polymer film; the polymer film was then immersed in an alkaline solution to obtain OH... - Type of anion exchange membrane.

[0060] Furthermore, the alkaline solution includes NaOH and / or KOH solution.

[0061] Furthermore, the temperature of the impregnation step is 25-80℃, and the impregnation time is 10-24h.

[0062] Furthermore, the sixth solvent includes at least one of dimethyl sulfoxide, N-methylpyrrolidone, N,N-dimethylformamide, or N,N-dimethylacetamide.

[0063] Furthermore, the solid-liquid ratio of the sterically hindered aryl quaternary ammonium polymer to the sixth solvent is 1 g:(6-15) mL.

[0064] Furthermore, the thickness of the polymer film is 20-60 μm.

[0065] The sixth technical solution of the present invention: providing an anion exchange membrane prepared by the above preparation method.

[0066] The seventh technical solution of the present invention is to provide the application of the above-mentioned anion exchange membrane in alkaline fuel cells and alkaline water electrolysis devices.

[0067] The present invention discloses the following technical effects:

[0068] This invention relates to a sterically hindered aryl polymer whose backbone contains sterically hindered structural units, which can effectively promote the formation of microphase separation structures within the membrane. These microphase separation structures construct high-speed ion transport channels within the membrane, thereby significantly improving the ionic conductivity of the anion exchange membrane. At the same time, by copolymerizing with quaternized structural units, the alkali resistance of the membrane material is further enhanced.

[0069] The preparation method of this invention is simple and low-cost, making it very suitable for large-scale industrial production. Furthermore, because the sterically hindered aryl polymer backbone does not contain ether bonds or heteroatoms, it endows the anion exchange membrane with excellent chemical stability, especially its outstanding stability under alkaline conditions.

[0070] The sterically hindered aryl polymer and its preparation method of this invention not only solve the problem of insufficient performance of anion exchange membranes in the prior art, but also meet the application requirements in fields such as alkaline fuel cells and alkaline water electrolysis devices. Experimental data show that the anion exchange membrane prepared by this invention has the following excellent properties: tensile strength up to 44 MPa and electrical conductivity up to 170 mS / cm. 2 At a potential of 2V, the current density can reach 2.30A / cm². 2 . Attached Figure Description

[0071] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0072] Figure 1 Example 1 of this invention is based on OH- sterically hindered polyaryl-3-piperidine copolymer. - Spectrum of a type anion exchange membrane.

[0073] Figure 2 Example 2 of the present invention is based on OH- sterically hindered polyaryl fluoroketone copolymer. - Spectrum of a type anion exchange membrane.

[0074] Figure 3 The ionic conductivity of the anion exchange membrane prepared in Example 1 of this invention at different temperatures.

[0075] Figure 4 The tensile strength and elongation at break of the anion exchange membrane prepared in Example 1 of the present invention are shown.

[0076] Figure 5 The polarization curve of the membrane electrode based on the anion exchange membrane in Example 1 of the present invention is shown at 80°C.

[0077] Figure 6 The in-situ durability curve of the anion exchange membrane in Example 1 of the present invention at 80°C is shown.

[0078] Figure 7 The ionic conductivity of the anion exchange membrane prepared in Example 2 of this invention at different temperatures.

[0079] Figure 8 The tensile strength and elongation at break of the anion exchange membrane prepared in Example 2 of the present invention are shown.

[0080] Figure 9 The spectrum of the sterically hindered aryl monomer and its reactants of this invention is shown. Detailed Implementation

[0081] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0082] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0083] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0084] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be readily apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0085] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0086] The method for synthesizing sterically hindered aryl polymers of the present invention can be used to synthesize a series of sterically hindered aryl polymers with different hydrophobic segments by adjusting the ratio of sterically hindered groups and linear phenyl monomers Ar under the catalysis of trifluoromethanesulfonic acid, and then prepare polymer membranes for use in anion exchange membrane alkaline water electrolysis devices and anion exchange membrane fuel cell devices.

[0087] In the following embodiments of the present invention, the sterically hindered aryl quaternized polymer is synthesized by adding a haloalkane with the corresponding structure and / or a trimethylamine solution to the sterically hindered aryl polymer for quaternization reaction.

[0088] In the following embodiments of the present invention, the anion exchange membrane is OH - The method for synthesizing the type anion exchange membrane is based on the sterically hindered aryl quaternary ammonium polymer, by forming a membrane through solvent evaporation, and then immersing the formed polymer membrane in an alkaline solvent.

[0089] It should be noted that any aspects not described in detail in this invention are conventional practices in the field and are not the focus of this invention.

[0090] Example 1

[0091] An OH based on a sterically hindered polyaryl-3-piperidine copolymer - The synthetic route for this type of anion exchange membrane is shown below:

[0092]

[0093] This embodiment OH- Type III anion exchange membranes are prepared by the following method:

[0094] (1) In a 100 mL three-necked flask, 2,7-dibromo-9,9'-spirodifluorene (1.90 g, 4.00 mmol), 3,5-bis(trifluoromethyl)phenylboronic acid (2.27 g, 8.80 mmol), and K₂CO₃ (1.11 g, 8.00 mmol) were added to a mixed solution of deionized water (10.00 mL) and toluene (40.00 mL). The mixture was stirred with a magnetic stirrer under a nitrogen atmosphere for 10 min. Then, tetra(triphenylphosphine palladium) (0.1155 g, 0.1 mmol) was injected under a N₂ atmosphere. After stirring at room temperature for 5 min, the reaction system was heated to 85 °C. During the reaction, the solution changed from yellow to grayish-black. After 24 h of reaction, 1 mL of methanol solution was injected into the system for quenching and post-treatment. After repeated extraction three times with dichloromethane and deionized water, anhydrous magnesium sulfate powder was finally added to remove water from the obtained organic phase. After standing for 30 minutes, the mixture was filtered, and the filtrate was dried by rotary evaporation at 50°C for 2 hours. The resulting product was then dried under vacuum at 60°C for 24 hours. After separation by silica gel column chromatography with hexane as solvent, a solution containing the coupling product was obtained. This solution was then dried under vacuum at 60°C for 24 hours, finally yielding the white coupling product 2,7-bis(3,5-bis(trifluoromethyl)phenyl)-9,9'-spirofluorene.

[0095] (2) In a 100 mL single-necked flask, p-terphenyl (1.00 g, 4.34 mmol), 3-piperidinone (0.56 g, 5.62 mmol) and 2,7-bis(3,5-bis(trifluoromethyl)phenyl)-9,9'-spirofluorene (0.57 g, 0.77 mmol) were added to dichloromethane (6.00 mL). The mixture was stirred with a magnetic stirrer in an ice-water bath under an air atmosphere for 10 min to obtain a yellowish-white mixed solution. Then, TFSA (4.00 mL, 46.69 mmol) was added dropwise to the above yellowish-white mixed solution. After the addition was complete, the mixture was stirred for 8 h. During the reaction, the color of the solution changed from yellowish-white to red and finally to purplish-red. The resulting viscous solution was poured into 500 mL of methanol solution, and a white polymer precipitated.

[0096] (3) The above white polymer was crushed, the fragments were collected by filtration, and washed with 1M K2CO3 solution at room temperature for 12h to neutralize the acid remaining in the reaction. Then it was washed three times with deionized water and dried in a vacuum oven at 80℃ for 12h to obtain sterically hindered polyaryl 3-piperidine copolymer (PF-SAP-15).

[0097] (4) In a flask, PF-SAP-15 (0.50 g) was dissolved in DMSO (20.00 mL) and stirred at room temperature for 30 min. Then, K2CO3 (0.60 g) and iodomethane (1.00 mL) were added, and the mixture was stirred in the dark at room temperature for 2 h. Subsequently, the mixture was heated to 50 °C and stirred for 48 h. 400 mL of ethyl acetate was added to the resulting viscous solution. The yellow precipitate was filtered, washed three times with deionized water, and dried in a vacuum oven at 80 °C for 12 h to obtain quaternized sterically hindered polyaryl 3-piperidine copolymer (QPF-SAP-15(I - ));

[0098] (5) QPF-SAP-15(I - (0.32 g) was dissolved in DMSO (4.00 mL), the solution was filtered through a polytetrafluoroethylene (PTFE) filter, cast onto a flat, clean glass plate, and then dried in an oven at 70 °C for 24 h to completely remove residual solvent, resulting in a 20 μm thick I... - Type of polymer film;

[0099] (6) Will I - The polymer membrane of type [type] was peeled off from the glass plate, immersed in 1M NaOH solution, and subjected to ion exchange at 60°C for 12 hours to obtain OH [type]. - The membrane (labeled QPF-SAP-15) was then washed three times with deionized water to obtain OH. - To avoid CO2 contamination and carbonate formation, the anion exchange membrane is stored by immersing it in deionized water purged with nitrogen.

[0100] Example 2

[0101] An OH based on a sterically hindered polyaryl fluoroketone copolymer - The synthetic route for this type of anion exchange membrane is shown below:

[0102]

[0103] This embodiment OH - Type III anion exchange membranes are prepared by the following method:

[0104] (1) In a 100 mL three-necked flask, 2,7-dibromo-9,9'-spirodifluorene (1.90 g, 4.00 mmol), 3,5-bis(trifluoromethyl)phenylboronic acid (2.27 g, 8.80 mmol), and K₂CO₃ (1.11 g, 8.00 mmol) were added to a mixed solution of deionized water (10.00 mL) and toluene (40.00 mL). The mixture was stirred with a magnetic stirrer under a nitrogen atmosphere for 10 min. Then, tetra(triphenylphosphine palladium) (0.1155 g, 0.1 mmol) was injected under a N₂ atmosphere. After stirring at room temperature for 5 min, the reaction system was heated to 85 °C. During the reaction, the solution changed from yellow to grayish-black. After 24 h of reaction, 1 mL of methanol solution was injected into the system for quenching and post-treatment. After repeated extraction three times with dichloromethane and deionized water, anhydrous magnesium sulfate powder was finally added to remove water from the obtained organic phase. After standing for 30 minutes, the mixture was filtered, and the filtrate was dried by rotary evaporation at 50°C for 2 hours. The resulting product was then dried under vacuum at 60°C for 24 hours. After separation by silica gel column chromatography with hexane as solvent, a solution containing the coupling product was obtained. This solution was then dried under vacuum at 60°C for 24 hours, finally yielding the white coupling product 2,7-bis(3,5-bis(trifluoromethyl)phenyl)-9,9'-spirofluorene.

[0105] (2) In a 100 mL single-necked flask, p-terphenyl (1.00 g, 4.34 mmol), 7-bromo-1,1,1-trifluoro-2-heptanone (1.31 g, 5.30 mmol) and 2,7-bis(3,5-bis(trifluoromethyl)phenyl)-9,9'-spirofluorene (0.36 g, 0.48 mmol) were added to dichloromethane (6.00 mL). The mixture was stirred with a magnetic stirrer in an ice-water bath under an air atmosphere for 10 min to obtain a white mixed solution. Then, TFSA (6.00 mL, 70.04 mmol) was added dropwise to the above white mixed solution. After the addition was complete, the reaction was stirred for 6 h. During the reaction, the color of the solution changed from white to red and finally to purplish-red. The resulting viscous solution was poured into a methanol solution, and a white polymer precipitated.

[0106] (3) The above white polymer was crushed, the fragments were collected by filtration, and washed with 1M K2CO3 solution at room temperature for 12h to neutralize the acid remaining in the reaction. Then it was washed three times with deionized water and dried in a vacuum oven at 80℃ for 12h to obtain sterically hindered polyaryl fluoroketone copolymer (PF-SA-10).

[0107] (4) In a flask, PF-SA-10 (0.50 g) was dissolved in NMP (20.00 mL) and stirred at room temperature for 30 min. Then, K2CO3 (0.60 g) and 30% wt trimethylamine ethanol solution (1.00 mL) were added, and the mixture was stirred in the dark at room temperature for 2 h. Subsequently, it was heated to 50 °C and stirred for 48 h. 400 mL of ethyl acetate was added to the resulting viscous solution, the yellow precipitate was filtered, washed three times with deionized water, and dried in a vacuum oven at 80 °C for 12 h to obtain quaternized sterically hindered polyaryl fluoroketone copolymer (QPF-SA-10(Br)). - ));

[0108] (5) QPF-SA-10(Br - (0.32 g) was dissolved in DMSO (4.00 mL), the solution was filtered through a polytetrafluoroethylene (PTFE) filter, cast onto a flat, clean glass plate, and then dried in an oven at 70 °C for 24 h to completely remove residual solvent, yielding a 20 μm thick Br film. - Type of polymer film;

[0109] (6) Br - The polymer membrane of type [type] was peeled off from the glass plate, immersed in 1M NaOH solution, and subjected to ion exchange at 60°C for 12 hours to obtain OH [type]. - The membrane (marked as QPF-SA-10) was then washed three times with deionized water. To avoid CO2 contamination and carbonate formation, the membrane was stored by immersing it in deionized water with nitrogen gas.

[0110] Example of effect verification:

[0111] 1. Conductivity test

[0112] The ionic conductivity of the membrane (σ, mS·cm) -1 The AC impedance (R, kΩ) of the anion exchange membrane (AEMs) was measured using a Shanghai Chenhua CHI 760E electrochemical workstation, with a frequency range of 1MHz to 1Hz and a potential amplitude of 10mA.

[0113] The testing procedure is as follows: The membrane sample was immersed in deionized water for 24 hours under a nitrogen atmosphere to allow it to reach water equilibrium. Strips of membrane longer than 1 cm were cut and sandwiched between two pairs of copper electrode plates spaced 1 cm apart. The membrane was then placed in a wide-mouthed bottle containing deionized water. Nitrogen gas was purged into the container for protection to prevent interference from CO2 in the air, as HCO3-... - and CO3 2- The ionic conductivity is lower than that of OH. -The water bath was heated to 30℃, 40℃, 50℃, 60℃, 70℃ and 80℃ respectively. Each specific temperature required equilibration for 2 hours before the AC impedance of the membrane could be measured.

[0114] The ionic conductivity of AEMs can be calculated using the formula.

[0115]

[0116] In the formula, L is the distance between the two electrode plates, A is the effective cross-sectional area of ​​the membrane, and R is the AC impedance of the membrane.

[0117] Figure 3 The ionic conductivity of the anion exchange membrane prepared in Example 1 is shown at different temperatures. It can be seen that the conductivity of the QPF-SAP-15 membrane at 80°C is 170 mS / cm. 2 The high level of conductivity among known structures indicates that the anion exchange membrane has good electrical conductivity.

[0118] Figure 7 The ionic conductivity of the anion exchange membrane prepared in Example 2 is shown at different temperatures. It can be seen that the conductivity of the QPF-SA-10 membrane at 80°C is 130.48 mS / cm. 2 The high level of conductivity among known structures indicates that the anion exchange membrane has good electrical conductivity.

[0119] 2. Mechanical property testing

[0120] Tensile tests were conducted on AEMs at room temperature using a MODEL universal testing machine from Shenzhen Sansi Zongheng Science Co., Ltd., with a relative humidity of 55% and a tensile rate of 10 mm / min; the tensile strength and elongation at break of the membrane samples were obtained.

[0121] Figure 4 The tensile strength and elongation at break of the anion exchange membrane prepared in Example 1 of this invention are shown. It can be seen that the elongation at break reaches approximately 10.5%, and the tensile strength exceeds 44 MPa, indicating that the anion exchange membrane has excellent mechanical properties.

[0122] Figure 8 The tensile strength and elongation at break of the anion exchange membrane prepared in Example 2 of this invention are shown. It can be seen that the elongation at break reaches approximately 10.7%, and the tensile strength exceeds 46 MPa, indicating that the anion exchange membrane has excellent mechanical properties.

[0123] 3. Alkaline water electrolysis performance test

[0124] OH prepared in Example 1 - The performance of the membrane electrode assembled from the anion exchange membrane was tested in a single cell of alkaline water electrolysis.

[0125] Take the OH prepared in Example 1 - An anion exchange membrane, an anode catalyst (nickel-iron catalyst), and a cathode catalyst (platinum-carbon catalyst) were assembled into a membrane electrode, installed in an AEM electrolytic cell, and electrochemical tests were performed on an Autolab electrochemical workstation.

[0126] The anode and cathode catalysts were 2cm × 2cm in size. A 1M KOH solution was used as the electrolyte in the AEM electrolytic cell. Before electrochemical testing, the solution was circulated for two hours to ensure a constant temperature and stable voltage. Then, the alkaline solution was replaced, and after stabilization for another half hour, the current-voltage (IV) polarization curve was recorded using a DC regulated power supply. For durability testing, the current was measured at 1A / cm². 2 Electrolysis of water was tested at a current density of [value missing].

[0127] Figure 5 The graph shows the polarization curve of the membrane electrode based on the anion exchange membrane in Example 1 at 80°C. It can be seen that at 80°C and a potential of 2V, the current density can reach 2.3 A / cm². 2 .

[0128] Figure 6 This is based on the in-situ durability curve of the anion exchange membrane in Example 1 at 80°C. It can be seen that under the condition of 80°C: at 1 A / cm... 2 At the specified current density, the total voltage drop rate of the QPF-SAP-15AEMWE single cell was less than 2% during nearly 1000 hours of testing.

[0129] In summary, based on the present invention, OH of a sterically hindered aryl polymer is provided. - This type of anion exchange membrane exhibits good mechanical stability and excellent electrical conductivity, demonstrating superior durability in water electrolysis device testing. By incorporating sterically hindered groups, the formation of the microphase separation structure of the anion exchange membrane is promoted, which helps to establish ion channels with lower transport resistance. Furthermore, its application in alkaline water electrolysis has proven the excellent performance of this type of polymer.

[0130] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A sterically hindered aryl polymer, characterized in that, It has a general formula structure as shown in equation (P): （P）； Where Ar is M is or The sum of x and y is 100%. In this context, * represents a connector.

2. The method for preparing the sterically hindered aryl polymer as described in claim 1, characterized in that, Includes the following steps: Ar group monomer, M corresponding ketone monomer and sterically hindered aryl structure monomer are mixed in a first solvent and reacted in the presence of a first catalyst. The resulting reaction solution is added to a second solvent, the precipitated solid is collected and dried to obtain sterically hindered aryl polymer. The structure of the sterically hindered aryl monomer is as follows: ; The preparation method of the sterically hindered aryl monomer includes the following steps: 2,7-Dibromo-9,9'-spirodifluorene and 3,5-bis(trifluoromethyl)phenylboronic acid were mixed in a third solvent and reacted in the presence of a second catalyst to obtain the sterically hindered aryl monomer.

3. The method for preparing the sterically hindered aryl polymer according to claim 2, characterized in that: The reaction is carried out in the presence of the first catalyst at a temperature of -5 to 15°C for a time of 0 to 48 hours, and not for 0 hours; the first catalyst includes trifluoroacetic acid and / or trifluoromethanesulfonic acid. The reaction is carried out in the presence of the second catalyst at a temperature of 60-90°C for a time of 12-36 h; the second catalyst includes at least one of Pd(PPh3)4, AsPh3, n-Bu3P and (MeO)3P.

4. A sterically hindered aryl quaternized polymer, characterized in that, It has a general formula structure as shown in equation (Q): （Q） Ar for ; QA is or ; The R3, R4, and R5 groups are independently chosen as hydrogen atoms or alkane groups containing 1-20 carbon atoms; The sum of x and y is 100%.

5. The method for preparing the sterically hindered aryl quaternary ammonium polymer as described in claim 4, characterized in that, Includes the following steps: The sterically hindered aryl polymer of claim 1 is mixed with a haloalkane or trimethylamine solution in a fourth solvent and reacted in the presence of a third catalyst. The resulting reaction solution is added to a fifth solvent, the precipitated solid is collected, and dried to obtain the sterically hindered aryl quaternized polymer.

6. A method for preparing an anion exchange membrane, characterized in that, Includes the following steps: The sterically hindered aryl quaternary ammonium polymer of claim 4 is added to a sixth solvent, and the resulting mixture is cast onto a substrate surface to obtain a polymer film; the polymer film is then impregnated in an alkaline solution to obtain OH... - Type of anion exchange membrane.

7. The anion exchange membrane prepared by the method according to claim 6.

8. The application of the anion exchange membrane as described in claim 7 in an alkaline fuel cell or an alkaline water electrolysis device.

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