Main chain type polyaryl piperidine polymer as well as preparation method and application thereof

Abstract

The invention relates to a main chain type polyaryl piperidine polymer as well as a preparation method and application thereof, and the preparation method comprises the following steps: dissolving a linear structure phenyl monomer, a strong bond energy linear structure phenyl monomer, 1, 2-diphenylethane and N-methyl-4-piperidone to obtain a precursor polymer solution; dropwise adding trifluoroacetic acid and trifluoromethanesulfonic acid to obtain a main chain type polyarene piperidine polymer precursor; and dissolving the polyaromatic piperidine, adding methyl iodide and potassium carbonate, reacting to obtain a quaternized main chain type polyaromatic piperidine polymer, and carrying out membrane treatment and alkali treatment processes to obtain the anion exchange membrane. By introducing the high-rigidity hydrophobic linear monomer with strong bond energy, the problem of mutual entanglement between linear main chains of a traditional polymer is solved, larger free volume and steric hindrance are provided, and high ionic conductivity and high alkali stability of the anion exchange membrane are realized; therefore, the water electrolysis performance of the anion exchange membrane electrolytic tank is further improved, and high-performance and high-stability electrolytic tank application is realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydrogen production by electrolysis of water, and specifically relates to a main-chain polyarylpiperidine polymer and a preparation method and application thereof, in particular to application in the preparation of anion exchange membranes. Background Art

[0002] Hydrogen technologies, including fuel cells and hydrogen generation systems (water electrolysis), have been proposed as potential solutions for achieving carbon neutrality within the next few decades. Anion exchange membrane fuel cells and water electrolyzers operating under alkaline conditions can utilize non-precious metal catalysts and hydrocarbon-based polyelectrolytes, significantly reducing the cost of energy devices. While significant progress has been made in the development of anion exchange membrane water electrolyzers, improvements are still needed, particularly in terms of in-situ durability and power density.

[0003] Over the past few decades, significant efforts have been made to develop high-performance poly(arylpiperidine) anion exchange membranes by adjusting the polymer backbone, cationic groups, and modification strategies. Despite significant progress in this field, most anion exchange membranes still face challenges in physical stability, electrical conductivity, and dimensional stability.

[0004] The trade-off between conductivity and dimensional stability is a major obstacle hindering the sustainable operation of anion exchange membrane water electrolyzers. Various strategies, including cross-linking, grafting, and block copolymer construction, have been reported to address this thorny issue. However, these approaches are limited by the choice of polymer backbone or complex synthesis processes. Highly rigid linear structures, on the other hand, have been proposed as a simple solution to this dilemma.

[0005] An existing patent discloses a branched block polyarylpiperidine polymer, an anion exchange membrane, and its preparation and application. Leveraging the significant convenience of introducing branched structural units into linear polymers for large-scale sample synthesis, the patent develops a polymer synthesis method that combines branched structural units, block linear structural units, and linear monomers to produce anion exchange membranes. However, the synthesis process of these block linear structural units involves numerous steps, significantly increasing the risk and complexity of sample preparation. Furthermore, the ionic conductivity of the anion exchange membranes synthesized by this method is far inferior to that of the currently mainstream main-chain anion exchange membranes.

[0006] Existing main-chain polyarylpiperidine polymers have poor electrical conductivity and mechanical properties, which limit their application in anion exchange membrane water electrolyzer devices. The present invention solves the problem of internal structural entanglement of traditional linear main-chain polyarylpiperidine polymers by introducing a small number of strong bond energy linear structural units into the structure, achieving the effect of generating free volume, promoting the formation of conductive paths, and facilitating the adsorption and transport of water molecules within the membrane. Summary of the Invention

[0007] The present invention addresses the problems existing in the prior art by providing a main-chain polyarylpiperidine polymer, its preparation method, and application. The polymer comprises strong-bond linear structural units and block linear structural units, and an anion exchange membrane can be obtained through further membrane treatment and alkali treatment. The present invention provides a simple process for preparing the anion exchange membrane, with high yield, and achieves high ionic conductivity and high alkali stability, thereby further improving the water electrolysis performance of anion exchange membrane electrolytic cells and enabling high-performance and high-stability electrolytic cell applications.

[0008] This series of backbone polymers based on a poly(fluorene / dibenzyl co-arylpiperidinium) backbone incorporates different strong-bond linear phenyl monomers, such as diphenylethylene and diphenylacetylene (highly rigid, linear structures), into the system. We found that highly rigid linear monomers have a significant advantage in generating free volume, which in turn promotes the formation of conductive pathways and facilitates the adsorption and transport of water molecules within the membrane.

[0009] The purpose of the present invention can be achieved by the following solutions:

[0010] The present invention provides a main chain polyarylpiperidine polymer, the structural formula of which is as follows:

[0011]

[0012] in, include

[0013] Ar1-1 is One or more of the following;

[0014] Ar1-2 is

[0015] Ar2 is

[0016] Ar2 is preferably

[0017] In the structural formula, Ar1 includes Ar1-1 and Ar1-2; It is a random mixed connection.

[0018] In the general structural formula, the molar ratio of Ar1-1, Ar2, and Ar1-2 is 12 to 18: 0.4 to 2: 2 to 8. Ar1 is a linear phenyl group, and Ar2 is a strong-bond linear phenyl group.

[0019] In the general structural formula, n is 85-97.5, and m is 15-2.5. m% and n% represent the molar percentages of Ar1 and Ar2, respectively (Ar1+Ar2), where m+n=100.

[0020] The present invention provides a method for preparing a main-chain polyarylpiperidine polymer, comprising the following steps:

[0021] S1, dissolving a linear phenyl monomer (Ar1-1), a strong bond energy linear phenyl monomer (Ar2), 1,2-diphenylethane and N-methyl-4-piperidone in an organic solvent 1, stirring and mixing to obtain a precursor polymer solution; adding trifluoroacetic acid and trifluoromethanesulfonic acid dropwise to the precursor polymer solution, stirring and reacting, and obtaining a precipitate as a main chain polyaromatic piperidine polymer precursor;

[0022] S2. Dissolving the main-chain polyaromatic piperidine polymer precursor in organic solvent 2, adding methyl iodide and potassium carbonate, and stirring to react. The resulting precipitate is the quaternized main-chain polyaromatic piperidine polymer.

[0023] As one embodiment of the present invention, in step S1, the linear phenyl monomer (Ar1-1) includes one or more of biphenyl (I), p-terphenyl (II), and fluorene (III). The structural formulas of the linear phenyl monomer (Ar1-1) are shown below I-III:

[0024]

[0025] As one embodiment of the present invention, in step S1, the strong bond energy linear structure phenyl monomer (Ar2) includes one or more of diphenylethylene (IV) and diphenylacetylene (V), preferably diphenylacetylene (V). The structural formula of the strong bond energy linear structure phenyl monomer (Ar2) is shown below as IV-V:

[0026]

[0027] The structural formula of 1,2-diphenylethane:

[0028] As one embodiment of the present invention, in step S1, the molar ratio of the linear phenyl monomer (Ar1-1), the strong bond linear phenyl monomer (Ar2), and 1,2-diphenylethane (Ar1-2) is 12-18:0.4-2:2-8. The molar ratio of the linear phenyl monomer (Ar1-1) and N-methyl-4-piperidone is 22-26:32-36.

[0029] As one embodiment of the present invention, in step S1, the organic solvent 1 is dichloromethane (purity greater than 99.5%). The linear phenyl monomer (Ar1-1), N-methyl-4-piperidone, and the organic solvent 1 are used in a ratio of 22-26 mmol: 32-36 mmol: 20-30 ml.

[0030] As an embodiment of the present invention, in step S1, the stirring and mixing temperature is -5 to -2°C, preferably -3°C, and the time is 10 to 40 minutes, preferably 30 minutes.

[0031] As an embodiment of the present invention, in step S1, the volume ratio of trifluoroacetic acid (TFA), trifluoromethanesulfonic acid (TFSA) and organic solvent 1 is 3-4:20-30:20-30, preferably 3:20:20.

[0032] As an embodiment of the present invention, in step S1, the stirring reaction time is 6 to 7 hours.

[0033] In one embodiment of the present invention, in step S1, a precipitate (main-chain polyaromatic piperidine polymer precursor) is obtained by pouring the stirred reaction solution into water. The resulting precipitate is then washed and dried. Washing is performed 3-5 times with deionized water, and drying is performed at 75-85°C under vacuum for 20-30 hours. The precipitate is insoluble in water, and water can also be used to wash away acid residues on the surface of the precipitated polymer.

[0034] As an embodiment of the present invention, in step S2, the ratio of the main chain polyaromatic piperidine polymer precursor to the organic solvent 2 is 1 g: 10-20 mL. The organic solvent 2 is dimethyl sulfoxide (with a purity greater than 99.9%).

[0035] As an embodiment of the present invention, in step S2, the usage ratio of the main chain polyaromatic piperidine polymer precursor, methyl iodide, and potassium carbonate is 1 g: 1.5-2.5 ml: 1.5-2.5 g.

[0036] As an embodiment of the present invention, in step S2, the stirring reaction time is 20 to 30 hours and the stirring reaction is carried out at room temperature (20 to 25° C.) in the dark.

[0037] In one embodiment of the present invention, in step S2, the precipitate (quaternized main-chain polyaromatic piperidine polymer) is obtained by adding the stirred reaction solution to ethyl acetate. The resulting precipitate is washed and dried. Washing is performed 3-5 times with deionized water, and drying is performed at 75-85°C under vacuum for 20-30 hours. The precipitate is insoluble in ethyl acetate, but ethyl acetate can also be used to wash away organic residues on the surface of the precipitated polymer.

[0038] The present invention provides an application of the main chain polyarylpiperidine polymer in preparing an anion exchange membrane.

[0039] The present invention provides a method for preparing an anion exchange membrane, comprising the following steps:

[0040] The quaternized main chain polyaromatic piperidine polymer is dissolved in an organic solvent 2, the filtered polymer solution is spread on a carrier, and dried to obtain 1 - Type membrane; - The membrane is peeled off and soaked in alkali solution to obtain an anion exchange membrane (OH - type film).

[0041] As one embodiment of the present invention, the usage ratio of the quaternized main chain polyaromatic piperidine polymer and the organic solvent 2 is 0.2 g: 3-8 ml.

[0042] As one embodiment of the present invention, the filtration is performed using a 0.45 μm polytetrafluoroethylene (PTFE) filter. Filtration can remove impurities such as dust from the polymer solution.

[0043] As one embodiment of the present invention, the drying is carried out at 70-90° C. for 20-30 hours.

[0044] As one embodiment of the present invention, the obtained - The thickness of the mold film is 10 to 30 μm.

[0045] As an embodiment of the present invention, the soaking temperature is 55-65°C and the soaking time is 10-20 hours. The soaking alkali solution is 1M KOH solution. - The membrane was washed with deionized water. - The membrane was stored in deionized water with nitrogen.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] (1) By adopting a one-pot method to polymerize polymer monomers under superacid conditions and innovatively introducing strong bond energy linear monomers, the problems of complex traditional polymer synthesis process, long synthesis time and low yield are solved, and the large-scale preparation of polymer precursors with stable chemical composition is achieved.

[0048] (2) By introducing strong bond energy linear monomers, the problem of interconnection between the linear main chains of traditional polymers is solved, the formation of microphase separation structure inside the polymer is promoted, and high dimensional stability and high mechanical properties of the anion exchange membrane are achieved.

[0049] (3) By introducing high-rigidity hydrophobic strong-bond linear monomers, the entanglement problem between the linear main chains of traditional polymers is solved, providing a larger free volume and steric hindrance, achieving high ionic conductivity and high alkaline stability of the anion exchange membrane, thereby further improving the water electrolysis performance of the anion exchange membrane electrolyzer. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0051] Figure 1 is a process flow chart of the present invention;

[0052] Figure 2 This is the hydrogen nuclear magnetic resonance spectrum of the main chain polyarylpiperidine polymer precursor prepared in Example 1;

[0053] Figure 3 This is the hydrogen nuclear magnetic resonance spectrum of the quaternized main-chain polyaromatic piperidine polymer prepared in Example 1;

[0054] Figure 4 The stress-strain curves of the anion exchange membranes prepared in Examples 1-2 and Comparative Example 1;

[0055] Figure 5 Ionic conductivity of the anion exchange membranes prepared in Examples 1-2 and Comparative Example 1 at different temperatures;

[0056] Figure 6 Electrochemical performance of oxygen evolution in electrolyzers (AEMWEs) of the anion exchange membrane prepared in Example 1;

[0057] Figure 7 Long-term stability test of the anion exchange membrane prepared in Example 1 in electrolyzers (AEMWEs);

[0058] Figure 8 This is the hydrogen nuclear magnetic resonance spectrum of the main chain polyarylpiperidine polymer precursor prepared in Example 2;

[0059] Figure 9 This is the hydrogen nuclear magnetic resonance spectrum of the quaternized main-chain polyaromatic piperidine polymer prepared in Example 2;

[0060] Figure 10 Electrochemical performance of oxygen evolution in electrolyzers (AEMWEs) of the anion exchange membrane prepared in Example 2;

[0061] Figure 11 This is a long-term stability test of the anion exchange membrane prepared in Example 2 in electrolyzers (AEMWEs). DETAILED DESCRIPTION

[0062] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments. The following examples are implemented under the premise of the technical solution of the present invention, provide detailed implementation methods and specific operating procedures, and will help those skilled in the art to further understand the present invention. It should be pointed out that the scope of protection of the present invention is not limited to the following embodiments, and a number of adjustments and improvements made under the premise of the concept of the present invention all fall within the scope of protection of the present invention.

[0063] The present invention relates to a main chain polyaryl piperidine polymer and an anion exchange membrane thereof, and a preparation method thereof is as follows Figure 1 As shown, the steps are as follows:

[0064] Step 1: Prepare a main-chain polyaryl piperidine polymer precursor: Add a predetermined amount of a linear phenyl monomer, a strong linear phenyl monomer, and N-methyl-4-piperidone to the resulting solution, adding organic solvent 1 to obtain a precursor polymer solution. Trifluoroacetic acid and trifluoromethanesulfonic acid are added dropwise to allow a reaction to proceed. After sufficient reaction, the solution is washed and dried to obtain a main-chain polyaryl piperidine polymer precursor.

[0065] Step 2, preparing a quaternized main-chain polyaryl piperidine polymer: dissolving the main-chain polyaryl piperidine polymer precursor obtained above in organic solvent 2, stirring, pouring a certain amount of iodomethane and potassium carbonate into the obtained solution, and after sufficient reaction, washing and drying to obtain a quaternized main-chain polyaryl piperidine polymer.

[0066] Step 3: Prepare an anion exchange membrane: Dissolve the quaternized main-chain polyarylpiperidine polymer in an organic solvent 2, filter, spread, and dry to obtain a type I membrane. Soak the type I membrane in an alkaline solution to obtain an anion exchange membrane.

[0067] In step 1, the precursor polymer solution is prepared as follows: a certain amount and a certain ratio of the aforementioned linear structure phenyl monomer, the strong bond energy linear structure phenyl monomer, and N-methyl-4-piperidone are weighed, and the aforementioned dichloromethane is poured into the mixture, and the mixture is stirred thoroughly to obtain a precursor polymer solution containing different types of strong bond energy linear structure phenyl monomers;

[0068] In step 1, the preparation process of the main-chain polyarylpiperidine polymer precursor is as follows: a certain amount of trifluoroacetic acid and trifluoromethanesulfonic acid are added to the above-mentioned precursor polymer solution, and the mixture is stirred thoroughly during the process. The temperature of the mixed solution is controlled within a certain range to obtain a viscous precursor polymer mixture. The precursor polymer mixture is repeatedly washed with water three times, dried in a vacuum drying oven overnight, and the product is collected to obtain a main-chain polyarylpiperidine polymer precursor.

[0069] In step 2, the preparation process of the quaternized main-chain polyaryl piperidine polymer is as follows: the main-chain polyaryl piperidine polymer precursor obtained above is dissolved in the aforementioned dimethyl sulfoxide, and a certain amount of iodomethane and potassium carbonate are added, and the mixture is stirred thoroughly during the process, and the reaction is carried out in the dark to obtain a quaternized polymer mixture. The quaternized polymer mixture is repeatedly washed three times with ethyl acetate and water, dried in a vacuum drying oven overnight, and the product is collected to obtain a quaternized main-chain polyaryl piperidine polymer.

[0070] In step 3, the anion exchange membrane preparation process is as follows: the quaternized polyarylpiperidine polymer obtained above is dissolved in the aforementioned dimethyl sulfoxide, filtered, spread on a glass plate, and dried to obtain a type I membrane. The type I membrane is then soaked in an alkaline solution and washed to obtain an anion exchange membrane.

[0071] Example 1

[0072] (1) Dissolve terphenyl (5.745 g, 24.948 mmol), 1,2-diphenylethane (1.515 g, 8.316 mmol), diphenylethylene (0.360 g, 2 mmol) and N-methyl-4-piperidone (3.87 g, 34.2 mmol) in dichloromethane (24 ml), stir at -3 ° C for 30 min to obtain a light green mixed solution, add TFA (3.6 ml) and TFSA (24 ml) dropwise thereto, stir at -3 ° C for 6.5 h, until the color of the mixed solution changes from light green to dark green. Pour the mixed solution into 500 ml of deionized water to precipitate a white polymer. Then wash it three times with deionized water and vacuum dry it at 80 ° C for 24 h to obtain a main chain polyaromatic piperidine polymer precursor. The nuclear magnetic resonance hydrogen spectrum is as follows Figure 2 As shown;

[0073] (2) The main chain polyaromatic piperidine polymer precursor (1 g) was dissolved in dimethyl sulfoxide (16 mL). Methyl iodide (2 ml) and potassium carbonate (2 g) were added under stirring at room temperature, and stirred in the dark for 24 h at room temperature. After the reaction was completed, it was added to an excess of ethyl acetate to obtain a white precipitate, which was washed three times, filtered, washed three times with deionized water, and dried in a vacuum at 80°C for 24 h to obtain a quaternized main chain polyaromatic piperidine polymer. The H NMR spectrum was as follows: Figure 3 As shown;

[0074] (3) A quaternized main-chain polyaromatic piperidine polymer (0.2 g) was dissolved in dimethyl sulfoxide (5 ml). The polymer solution was filtered through a 0.45 μm polytetrafluoroethylene (PTFE) filter, cast on a clean glass plate (6 cm * 6 cm), and dried at 80 °C for 24 h to completely remove the residual solvent, obtaining a 15 μm thick type I membrane.

[0075] (4) The I-type film was peeled off from the glass plate and immersed in 1M KOH solution at 60°C for 12 h to obtain OH - The membrane was washed with deionized water for 3 times. To avoid CO2 pollution and carbonate formation, the OH - The membrane was stored in deionized water with nitrogen.

[0076] Example 2 (Preferred Option 1: Replacing the Type of Strong Bond Energy Linear Structure Phenyl Monomer)

[0077] (1) Dissolve terphenyl (5.745 g, 24.948 mmol), 1,2-diphenylethane (1.515 g, 8.316 mmol), diphenylacetylene (0.356 g, 2 mmol) and N-methyl-4-piperidone (3.87 g, 34.2 mmol) in dichloromethane (24 ml), stir at -3 ° C for 30 min to obtain a light green mixed solution, add TFA (3.6 ml) and TFSA (24 ml) dropwise thereto, stir at -3 ° C for 6.5 h, until the color of the mixed solution changes from light green to dark green. Pour the mixed solution into 500 ml of deionized water to precipitate a white polymer. Then wash it three times with deionized water and vacuum dry it at 80 ° C for 24 h to obtain a main chain polyaromatic piperidine polymer precursor. The nuclear magnetic resonance hydrogen spectrum is as follows Figure 8 As shown;

[0078] (2) The main chain polyaromatic piperidine polymer precursor (1 g) was dissolved in dimethyl sulfoxide (16 mL). Methyl iodide (2 ml) and potassium carbonate (2 g) were added under stirring at room temperature, and stirred in the dark for 24 h at room temperature. After the reaction was completed, it was added to an excess of ethyl acetate to obtain a white precipitate, which was washed three times, filtered, washed three times with deionized water, and dried in a vacuum at 80°C for 24 h to obtain a quaternized main chain polyaromatic piperidine polymer. The H NMR spectrum was as follows: Figure 9 As shown;

[0079] (3) A quaternized main-chain polyaromatic piperidine polymer (0.2 g) was dissolved in dimethyl sulfoxide (5 ml). The polymer solution was filtered through a 0.45 μm polytetrafluoroethylene (PTFE) filter, cast on a clean glass plate (6 cm * 6 cm), and dried at 80 °C for 24 h to completely remove the residual solvent, obtaining a 15 μm thick type I membrane.

[0080] (4) The I-type membrane was peeled off from the glass plate and immersed in 1 M KOH solution at 60 °C for 12 h to obtain the OH-type membrane, which was then washed three times with deionized water to avoid CO 2 pollution and carbonate formation, OH - The membrane was stored in deionized water with nitrogen.

[0081] Comparative Example 1 (linear monomer without strong bond energy)

[0082] The preparation method of the present invention is substantially the same as that of Example 2, except that no diphenylethylene is added.

[0083] (1) Dissolve terphenyl (5.745 g, 24.948 mmol), 1,2-diphenylethane (1.515 g, 8.316 mmol) and N-methyl-4-piperidone (3.87 g, 34.2 mmol) in dichloromethane (24 ml), stir at -3 ° C for 30 min to obtain a light green mixed solution, add TFA (3.6 ml) and TFSA (24 ml) dropwise thereto, stir at -3 ° C for 6.5 h, until the color of the mixed solution changes from light green to dark green. Pour the mixed solution into 500 ml of deionized water to precipitate a white polymer. Then wash with deionized water three times and vacuum dry at 80 ° C for 24 h to obtain a main chain polyaromatic piperidine polymer precursor;

[0084] (2) Dissolve the main chain polyaromatic piperidine polymer precursor (1 g) in dimethyl sulfoxide (16 mL). Add iodomethane (2 ml) and potassium carbonate (2 g) under stirring at room temperature, and stir in the dark for 24 h at room temperature. After the reaction is completed, add it to excess ethyl acetate to obtain a white precipitate, wash it three times, filter it, wash it with deionized water three times, and dry it in vacuum at 80°C for 24 h to obtain a quaternized main chain polyaromatic piperidine polymer;

[0085] (3) A quaternized main-chain polyaromatic piperidine polymer (0.2 g) was dissolved in dimethyl sulfoxide (5 ml). The polymer solution was filtered through a 0.45 μm polytetrafluoroethylene (PTFE) filter, cast on a clean glass plate (6 cm * 6 cm), and dried at 80 °C for 24 h to completely remove the residual solvent, obtaining a 15 μm thick type I membrane.

[0086] (4) The I-type membrane was peeled off from the glass plate and immersed in 1 M KOH solution at 60 °C for 12 h to obtain the OH-type membrane, which was then washed three times with deionized water to avoid CO 2 pollution and carbonate formation, OH - The membrane was stored in deionized water with nitrogen.

[0087] Comparative Example 2

[0088] The preparation method of the present invention is substantially the same as that of Example 2, except that no 1,2-diphenylethane is added.

[0089] (1) Dissolve terphenyl (5.745 g, 24.948 mmol), diphenyl acetylene (0.356 g, 2 mmol) and N-methyl-4-piperidone (3.87 g, 34.2 mmol) in dichloromethane (24 ml), stir at -3 ° C for 30 min to obtain a light green mixed solution, add TFA (3.6 ml) and TFSA (24 ml) dropwise thereto, stir at -3 ° C for 6.5 h, until the color of the mixed solution changes from light green to dark green. Pour the mixed solution into 500 ml of deionized water to precipitate a white polymer. Then wash with deionized water three times and vacuum dry at 80 ° C for 24 h to obtain a main chain polyaromatic piperidine polymer precursor;

[0090] (2) Dissolve the main chain polyaromatic piperidine polymer precursor (1 g) in dimethyl sulfoxide (16 mL). Add iodomethane (2 ml) and potassium carbonate (2 g) under stirring at room temperature, and stir in the dark for 24 h at room temperature. After the reaction is completed, add it to excess ethyl acetate to obtain a white precipitate, wash it three times, filter it, wash it with deionized water three times, and dry it in vacuum at 80°C for 24 h to obtain a quaternized main chain polyaromatic piperidine polymer;

[0091] (3) A quaternized main-chain polyaromatic piperidine polymer (0.2 g) was dissolved in dimethyl sulfoxide (5 ml). The polymer solution was filtered through a 0.45 μm polytetrafluoroethylene (PTFE) filter, cast on a clean glass plate (6 cm * 6 cm), and dried at 80 °C for 24 h to completely remove the residual solvent, obtaining a 15 μm thick type I membrane.

[0092] (4) The I-type membrane was peeled off from the glass plate and immersed in 1 M KOH solution at 60 °C for 12 h to obtain the OH-type membrane, which was then washed three times with deionized water to avoid CO 2 pollution and carbonate formation, OH - The membrane was stored in deionized water with nitrogen.

[0093] The molecular weight of the polymer prepared by this method is too small, and a block solid cannot be precipitated during the first step of synthesis, which does not meet the subsequent film formation requirements.

[0094] Comparative Example 3

[0095] The preparation method of the present invention is substantially the same as that of Example 2, except that diphenylethylene is replaced with an equimolar amount of 1,2-diphenylethane.

[0096] Comparative Example 4

[0097] The preparation method of the present invention is substantially the same as that of Example 2, except that diphenylethylene is replaced by an equimolar amount of biphenyl.

[0098] Comparative Examples 4-5 are similar to Comparative Example 2. The molecular weight of the polymer prepared by this method is too small, and no bulk solid can be precipitated in the first step of synthesis, which does not meet the subsequent film formation requirements.

[0099] Performance testing method:

[0100] (1) Water absorption and swelling

[0101] The membrane sample was soaked in 1M NaOH for 48 hours for ion exchange, then washed several times with deionized water to remove excess alkali solution to obtain an OH-type AEM sample. The membrane sample was stored in deionized water for use. The membrane sample was cut into squares (2*2cm) and soaked in deionized water for 12 hours. The membrane sample was then removed, and the water droplets on the membrane surface were wiped dry with filter paper. The mass (M1) and length (L1) of the membrane sample were immediately tested. The wet membrane sample was then placed in a vacuum drying oven and vacuum dried to constant weight. Its dry weight (M2) and length (L2) were tested. The swelling ratio (Sr) and water absorption (Wu) of the membrane can be calculated using the following formula:

[0102] Sr (%) = (L1-L2) / L2

[0103] Wu (%) = (M1-M2) / M2

[0104] (2) Conductivity at 60°C

[0105] The ionic conductivity of the membrane was measured using a four-probe alternating current (AC) impedance analyzer over a frequency range of 0.1 to 100 kHz. Rectangular samples (1 × 3 cm) of the OH- form were placed on two platinum electrodes and then assembled in a homemade conductive mold. Before measurement, the cell was charged at a constant voltage for 4 hours at 50°C to eliminate the CO2 effect. The ohmic impedance of the membrane was recorded under a fully humidified N2 environment at different temperatures (30 to 80°C in 10°C increments) in a fuel cell test station.

[0106] (3) Intrinsic viscosity

[0107] The intrinsic viscosity of the main chain polymer was measured using an Ubbelohde viscometer in a DMSO solution at 25°C. First, the target sample was dissolved in DMSO to form a 3 mg mL -1 The polymer solution was then automatically diluted in sequence to five concentrations (3.0, 2.5, 2.0, 1.5, and 1.0 mg mL -1 ), and record the outflow time five times.

[0108] (4) Tensile strength and elongation at break

[0109] AEM samples were cut into dumbbell shapes (1 x 5 cm) using a specialized film cutter. The AEM samples were then secured in the slots of a tensile testing machine. The tensile strength and elongation at break of the AEM were measured at room temperature. The tensile speed was 10 mm / min.

[0110] The products obtained in Examples 1-2 were subjected to performance tests, and the performance is shown in Table 1 below:

[0111] Table 1 Performance test results

[0112]

[0113] The stress-strain curves of the anion exchange membranes prepared in Examples 1-2 and Comparative Example 1 are as follows: Figure 4 As shown; the ionic conductivity of the anion exchange membrane prepared in Example 1-2 and Comparative Example 1 at different temperatures is as shown Figure 5 shown.

[0114] (7) Electrolyzer test

[0115] The anode used uncatalyzed nickel felt, and the cathode used carbon paper loaded with a Pt / C catalyst. The anode and cathode, along with the membrane, were placed in a custom-made anion exchange membrane electrolyzer. Testing was performed using a Blue Electric test system.

[0116] The electrochemical performance of oxygen evolution of the anion exchange membranes prepared in Examples 1-2 in electrolyzers (AEMWEs) is as follows: Figure 6 、 Figure 10 As shown; long-term stability tests are as follows Figure 7 、 Figure 11 shown.

[0117] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art may make various variations or modifications within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A main chain polyarylpiperidine polymer, characterized in that The structural formula is as follows: in, include Ar1-1 is One or more of the following; Ar1-2 is Ar2 is and / or 2. The main chain polyarylpiperidine polymer according to claim 1, characterized in that In the structural formula, the molar ratio of Ar1-1, Ar2, and Ar1-2 is 12-18:0.4-2:2-8.

3. A method for preparing a main chain polyarylpiperidine polymer according to claim 1, characterized in that: The steps include: S1. Dissolving a linear phenyl monomer, a strong bond linear phenyl monomer, 1,2-diphenylethane, and N-methyl-4-piperidone in an organic solvent 1, and stirring and mixing to obtain a precursor polymer solution; adding trifluoroacetic acid and trifluoromethanesulfonic acid dropwise to the precursor polymer solution, stirring and reacting, and obtaining a precipitate as a main-chain polyaromatic piperidine polymer precursor; S2. Dissolving the main-chain polyaromatic piperidine polymer precursor in organic solvent 2, adding methyl iodide and potassium carbonate, and stirring to react. The resulting precipitate is the quaternized main-chain polyaromatic piperidine polymer.

4. The method for preparing a main chain polyarylpiperidine polymer according to claim 3, wherein In step S1, the linear structure phenyl monomer includes one or more of biphenyl, p-terphenyl, and fluorene; And / or, the strong bond energy linear structure phenyl monomer includes one or more of phenylethylene and diphenylacetylene.

5. The method for preparing the main chain polyarylpiperidine polymer according to claim 3, wherein In step S1, the molar ratio of the linear structure phenyl monomer, the strong bond energy linear structure phenyl monomer, and 1,2-diphenylethane is 12-18:0.4-2:2-8; and / or, the molar ratio of the linear phenyl monomer to N-methyl-4-piperidone is 22-26:32-36; And / or, the usage ratio of the linear phenyl monomer, N-methyl-4-piperidone, and the organic solvent 1 is 22-26 mmol: 32-36 mmol: 20-30 ml; And / or, the volume ratio of trifluoroacetic acid, trifluoromethanesulfonic acid and organic solvent 1 is 3-4:20-30:20-30.

6. The method for preparing the main chain polyarylpiperidine polymer according to claim 3, wherein In step S1, the stirring and mixing temperature is -5 to -2°C and the time is 10 to 40 minutes.

7. The method for preparing the main chain polyarylpiperidine polymer according to claim 3, wherein: In step S2, the usage ratio of the main chain polyaromatic piperidine polymer precursor, methyl iodide, and potassium carbonate is 1 g: 1.5-2.5 ml: 1.5-2.5 g.

8. Use of the main chain polyarylpiperidine polymer according to claim 1 in the preparation of anion exchange membranes.

9. A method for preparing an anion exchange membrane, characterized in that: The steps include: The main chain polyaryl piperidine polymer according to claim 1 is dissolved in an organic solvent 2, the filtered polymer solution is spread on a carrier, and dried to obtain 1 - Type membrane; - The membrane is peeled off and soaked in alkaline solution to obtain an anion exchange membrane.

10. The method for preparing an anion exchange membrane according to claim 9, characterized in that: The ratio of the main chain polyaromatic piperidine polymer and the organic solvent 2 is 0.2 g: 3-8 ml; and / or, drying is performed at 70 to 90° C. for 20 to 30 hours; And / or, the obtained I - The thickness of the mold film is 10 to 30 μm; And / or, the soaking temperature is 55-65° C. and the soaking time is 10-20 hours.

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