A multi-block carbazole-based polyarene piperidine anion exchange membrane and application thereof

Abstract

This invention provides a multi-block carbazole-based polyaromatic piperidine polymer, comprising the structural units shown in formula (I). This invention introduces carbazole aryl groups into the polymer backbone of aromatic hydrocarbons and piperidine ketones. Since the benzene ring in the carbazole aryl group lacks internal rotational functionality, the conductivity of the anion exchange membrane is effectively improved. Introducing fluorinated hydrophobic compounds into the polyaromatic hydrocarbon and piperidine ketone backbone promotes the microphase separation structure of the anion exchange membrane, thereby increasing the ion transport rate. The multi-block carbazole-based polyaromatic piperidine anion exchange membrane exhibits excellent chemical stability, film-forming properties, conductivity, and mechanical strength. This anion exchange membrane demonstrates excellent performance and durability in alkaline water electrolysis. The preparation process provided by this invention reduces or eliminates the use of traditional liquid acid catalysts, using solid acid and solid superacid catalysts, which can be reused.

Description

Technical Field

[0001] This invention belongs to the field of anion exchange membrane preparation technology for hydrogen production by water electrolysis, and relates to a multi-block carbazole polyaromatic piperidine polymer and its preparation method and application, an anion exchange membrane and its application, and particularly to a multi-block carbazole polyaromatic piperidine anion exchange membrane and its application. Background Technology

[0002] Developing and utilizing renewable energy technologies (such as solar cells, wind power, and fuel cells) is considered the most viable way to solve energy and environmental problems. Hydrogen production via water electrolysis, using renewable energy to produce hydrogen as fuel or chemical feedstock, will become an indispensable part of future renewable energy systems. Although traditional water electrolysis technology has been commercialized for over 100 years, its further application is limited by its low energy efficiency and high explosion risk. To meet future hydrogen production needs, advanced water electrolysis technologies with high energy efficiency, compact structure, and better gas separation performance are being widely developed. Anion exchange membrane water electrolysis combines the high efficiency and convenience of proton exchange membrane water electrolysis with the cost-effectiveness of traditional alkaline water electrolysis using non-precious metal catalysts. Therefore, anion exchange membrane water electrolysis has a higher competitiveness in the future large-scale hydrogen production field.

[0003] Chemical (alkaline) stability, mechanical stability, and ionic conductivity are the three most important properties for evaluating anion exchange membranes. Currently, numerous studies both domestically and internationally on anion exchange membranes with high conductivity and high stability have shown that improving the alkali resistance of quaternary ammonium cation groups and developing polymer backbones without ether oxygen bonds are effective methods to enhance the alkali resistance of anion exchange membranes. Numerous literature reports indicate that piperidine quaternary ammonium groups exhibit excellent alkali resistance in alkaline environments, and that ether-free polyalkane and polyaromatic polymer backbones are the best. Among these, utilizing the fact that the benzene ring in carbazole aryl groups lacks internal rotational function can improve the conductivity of anion exchange membranes. For example, patent 202110999989.1 discloses a method for preparing a carbazole-based polyaromatic piperidine anion exchange membrane. The invented carbazole-based polyaromatic anion exchange membrane achieves excellent conductivity and alkali resistance through polymer chemical structure design. Embedding fluorinated hydrophobic compounds in the backbone promotes the microphase separation structure of the anion exchange membrane, thereby increasing the ion transport rate. For example, multi-block polyphenylpiperidine anion exchange membranes (Angew. Chem. Int. Ed. 2023, 62, 10-11) disclose not only extremely high conductivity and alkali resistance, but also excellent water electrolysis performance and durability. However, the above examples all use trifluoromethanesulfonic acid as a homogeneous catalyst, with an addition amount 10 to 20 times the molar number of the aryl polymer. Moreover, homogeneous catalysts are difficult to reuse, generating a large amount of waste liquid during the preparation process, making the preparation process neither green nor environmentally friendly, and increasing the preparation cost.

[0004] Therefore, finding a more suitable anion exchange membrane that can solve the above-mentioned problems of existing technology and improve the performance of anion exchange membranes has become one of the focuses of attention for many front-line researchers in the industry. Summary of the Invention

[0005] In view of this, the technical problem to be solved by the present invention is to provide a multi-block carbazole-based polyaromatic piperidine polymer and its preparation method and application, an anion exchange membrane and its application, particularly a multi-block carbazole-based polyaromatic piperidine anion exchange membrane. The anion exchange membrane prepared by the present invention not only has excellent mechanical stability, but also excellent OH- ion exchange capacity. - It exhibits high electrical conductivity and extremely high alkali resistance. The preparation method of this invention is simple, environmentally friendly, and low-cost, making it more suitable for industrial production and application.

[0006] This invention provides a multi-block carbazole-based polyaromatic piperidine polymer, the multi-block carbazole-based polyaromatic piperidine polymer comprising the structural unit shown in formula (I):

[0007]

[0008] Where n = 1 to 50; in formula (I), Ar1 contains carbazole aromatic groups, and Ar2 does not contain carbazole aromatic groups;

[0009] The Ar1 is selected from the groups shown in formula (II) and / or formula (III):

[0010]

[0011] Where a = 1 to 6, p = 1 to 6, q = 1 to 6;

[0012] The Ar2 is selected from one or more of biphenyl, p-terphenyl, p-tetraphenyl, m-terphenyl, diphenylmethane, diphenylethane, 1,3,5-triphenylbenzene and acenaphthene;

[0013] The R1 is selected from one or more groups shown in formulas (IV) to (VIII):

[0014]

[0015] This invention provides a method for preparing multi-block carbazole polyaromatic piperidine polymers as described above, comprising the following steps:

[0016] 1) After mixing Ar1 monomer, Ar2 monomer and solvent to obtain a solution, N-methyl-4-piperidinone monomer and 2,2,2-trifluoroacetophenone are added to obtain a mixed solution;

[0017] 2) After reacting the mixed solution obtained in the above steps under the action of an acid catalyst, a precipitant is added to precipitate the mixture, and the polymer is obtained.

[0018] 3) After mixing the polymer obtained in the above steps with the organic solvent again, a quaternization reaction is carried out under the action of a quaternization reagent, and after precipitation, a multi-block carbazole polyaromatic piperidine polymer is obtained.

[0019] Preferably, the molar ratio of Ar1 monomer to Ar2 monomer is (1-50):(99-50);

[0020] The solvent includes one or more of dimethyl sulfoxide, N-methylpyrrolidone, N,N-dimethylformamide, dichloromethane, diethyl ether, and tetrahydrofuran;

[0021] The solution may be a homogeneous solution or a heterogeneous solution;

[0022] The ratio of the total molar number of Ar1 monomer and Ar2 monomer to the total molar number of N-methyl-4-piperidinone and 2,2,2-trifluoroacetophenone is 1:(1-5);

[0023] The molar ratio of N-methyl-4-piperidinone and 2,2,2-trifluoroacetophenone is (9-5):(1-5).

[0024] Preferably, the acid catalyst comprises a solid acid and a liquid acid;

[0025] The solid acid includes one or more of ZSM-5, Y-type molecular sieve, and β-type molecular sieve;

[0026] The acid catalyst also includes a solid superacid;

[0027] The solid superacid includes Pt / SO4. 2- -ZrO2, S2O8 2- / CeO2-RF、CF3SO3H / ZrO2-Al2O3、SO4 2- / ZrO2、Pt-SO4 2- / ZrO 2- -Al2O3, SO4 2- / Fe2O3、SO4 2- / ZrO 2- -La2O3, SO4 2 - / SiO 2- -ZrO2, SO4 2- / M x O y and SO4 2- / ZrO 2- One or more of NiO / Al2O3;

[0028] The liquid acid includes one or more of trifluoromethanesulfonic acid, trifluoroacetic acid, and methanesulfonic acid;

[0029] The mass ratio of the solid acid to the sum of Ar1 and Ar2 is 100:(50-100);

[0030] The molar ratio of the liquid acid to the sum of Ar1 and Ar2 is (5-13):1;

[0031] The mass ratio of the solid superacid to the sum of Ar1 and Ar2 is 100:(20-60).

[0032] Preferably, the reaction temperature is -4 to 150°C;

[0033] The reaction time is 4–72 hours;

[0034] The precipitant includes one or more of methanol, NaOH, and water;

[0035] The precipitation step in step 2) also includes a washing step;

[0036] The washing process specifically involves standing in a potassium carbonate solution and standing in water.

[0037] The temperature at which the potassium carbonate solution is allowed to stand is 25–80°C.

[0038] The standing time in the potassium carbonate solution is 5–72 hours;

[0039] The temperature at which the water is kept still is 25–80°C;

[0040] The time for standing in water is 5 to 72 hours.

[0041] Preferably, the organic solvent includes one or more of N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylformamide, and N,N-dimethylacetamide;

[0042] The temperature for the remixing is 25–120°C;

[0043] The quaternization reaction includes a single quaternization reaction or two quaternization reactions;

[0044] The quaternizing agent for the primary quaternization reaction includes iodomethane;

[0045] The quaternizing agents for the two quaternization reactions include 1,6-dibromohexane, and one or more of trimethylamine, N-methylpiperidine, 4-vinylbenzyl chloride, and 4,4'-trimethylenebis(1-methylpiperidine);

[0046] The mass ratio of the polymer to the quaternizing agent is 1:(1-5);

[0047] The quaternization reaction takes 6–72 hours;

[0048] In step 4), precipitation can be carried out by adding ethyl acetate.

[0049] This invention provides the application of the multi-block carbazole polyaromatic piperidine polymer described in the above technical solutions or the multi-block carbazole polyaromatic piperidine polymer prepared by any of the preparation methods described in the above technical solutions in anion exchange membranes.

[0050] This invention provides an anion exchange membrane, wherein the anion exchange membrane is a multi-block carbazole polyarylene piperidine anion exchange membrane;

[0051] The anion exchange membrane includes an alkalized multi-block carbazole polyaromatic piperidine polymer.

[0052] The multi-block carbazole polyaromatic piperidine polymer is the multi-block carbazole polyaromatic piperidine polymer according to claim 1 or the multi-block carbazole polyaromatic piperidine polymer prepared by the preparation method according to any one of claims 2 to 6.

[0053] Preferably, the multi-block carbazole-based polyarylene piperidine anion exchange membrane is prepared by the following steps:

[0054] After mixing the multi-block carbazole polyaromatic piperidine polymer with a polar solution, a homogeneous solution of anion exchange resin is obtained. The homogeneous solution of anion exchange resin is then cast onto a substrate to form a film, which is then dried to form a membrane. After soaking in potassium hydroxide solution, the membrane is dried to obtain a multi-block carbazole polyaromatic piperidine anion exchange membrane in the form of hydroxide ions.

[0055] The concentration of the homogeneous solution of the anion exchange resin is 3 wt% to 25 wt%.

[0056] The molding time is 6–48 hours;

[0057] The molding temperature is 25–120°C;

[0058] The soaking time is 6–48 hours;

[0059] The soaking temperature is 25–80°C.

[0060] This invention provides the application of the multi-block carbazole polyaromatic piperidine polymer described in the above-mentioned technical solutions, the multi-block carbazole polyaromatic piperidine polymer prepared by any of the preparation methods described in any of the above-mentioned technical solutions, or the multi-block carbazole polyaromatic piperidine anion exchange membrane described in any of the above-mentioned technical solutions in the field of hydrogen production by water electrolysis.

[0061] This invention provides a multi-block carbazole-based polyaromatic piperidine polymer, comprising the structural unit shown in formula (I). Compared with the prior art, this invention addresses the shortcomings of current anion exchange membranes, such as low conductivity, high water absorption and swelling rates, poor chemical stability, and the large amount of liquid acid catalyst required for preparation that is difficult to reuse. It specifically designs a multi-block carbazole-based polyaromatic piperidine polymer with a specific structure and its preparation method. This invention introduces carbazole aryl groups into the polymer backbone of aromatic hydrocarbons and piperidine ketones. Since the benzene ring in the carbazole aryl group does not possess internal rotational function, the conductivity of the anion exchange membrane is effectively improved. The introduction of fluorinated hydrophobic compounds into the polyaromatic hydrocarbon and piperidine ketone backbone promotes the microphase separation structure of the anion exchange membrane, thereby increasing the ion transport rate. The multi-block carbazole-based polyaromatic piperidine anion exchange membrane exhibits excellent chemical stability, film-forming properties, conductivity, and mechanical strength. This anion exchange membrane demonstrates excellent performance and durability in alkaline water electrolysis. The preparation process provided by this invention reduces or eliminates the use of traditional liquid acid catalysts, and uses solid acid and solid superacid catalysts, which can be reused.

[0062] The preparation process of the multi-block carbazole-based polyaromatic piperidine polymer provided by this invention allows for the complete replacement of liquid acid with solid acid or solid superacid catalyst. However, it requires the selection of high-boiling-point solvents, extended reaction time, and increased reaction temperature during the preparation process. In low-boiling-point solvents and at low temperatures, the addition of solid acid can reduce the amount of liquid acid used by 30%, and the addition of solid superacid can reduce the amount of liquid acid used by 50%. Furthermore, the solid acid and solid superacid catalyst can be reused. The preparation method is simple and has low production costs. The multi-block carbazole-based polyaromatic piperidine polymer prepared by this invention exhibits excellent performance as anion exchange membranes, is suitable for industrial casting, has high mechanical strength, and can be applied to alkaline fuel cells, electrodialysis, and anion exchange membrane water electrolysis for hydrogen production.

[0063] This invention introduces carbazole-based aryl compounds and fluorinated hydrophobic compounds into the polymer backbone of aromatic hydrocarbons and piperidinones, promoting the microphase separation structure of the anion exchange membrane and improving ion transport capacity and alkaline stability. Furthermore, this invention is the first to employ a green preparation method using solid acid and a solid superacid catalyst, reducing the amount of liquid acid used and allowing for the reuse of the solid catalyst. The anion exchange membrane prepared by this invention not only exhibits excellent mechanical stability but also superior electrical conductivity (188 mS / cm @ 90℃); after immersion in 1M KOH solution at 80℃ for 2000 h, the conductivity loss is <5%, demonstrating extremely high alkali resistance. Further, when the anion exchange membrane is assembled into an alkaline water electrolysis membrane electrode, it operates stably for 1000 h without a significant voltage increase. The preparation method of this invention is simple, environmentally friendly, and low-cost. The anion exchange membrane prepared using this invention can be applied in fields such as alkaline anion exchange membrane water electrolysis for hydrogen production, alkaline fuel cells, and carbon dioxide catalytic reduction.

[0064] Experimental results show that the multi-block carbazole-based polyarylene piperidine anion exchange membrane prepared in this invention has excellent OH... - The conductivity (188 mS / cm @ 90℃) and alkali resistance (conductivity loss < 5% in 1M KOH solution at 80℃ for 2000 h) were excellent. The alkaline water electrolysis membrane electrode assembly (AEMWE) composed of multi-block carbazole polyaromatic piperidine anion exchange membrane operated stably for 1000 h without voltage rise. Detailed Implementation

[0065] To further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention and not for limiting the claims of the present invention.

[0066] There are no particular restrictions on the source of any raw materials used in this invention; they can be purchased from the market or prepared using conventional methods known to those skilled in the art.

[0067] The purity of the raw materials used in this invention is not particularly limited; analytical grade or the purity requirements of raw materials for AEMWE cathode electrode materials well known to those skilled in the art can be used.

[0068] This invention provides a multi-block carbazole-based polyaromatic piperidine polymer, the multi-block carbazole-based polyaromatic piperidine polymer comprising the structural unit shown in formula (I):

[0069]

[0070] Where n = 1 to 50; in formula (I), Ar1 contains carbazole aromatic groups, and Ar2 does not contain carbazole aromatic groups;

[0071] The Ar1 is selected from the groups shown in formula (II) and / or formula (III):

[0072]

[0073] Where a = 1 to 6, p = 1 to 6, q = 1 to 6;

[0074] The Ar2 is selected from one or more of biphenyl, p-terphenyl, p-tetraphenyl, m-terphenyl, diphenylmethane, diphenylethane, 1,3,5-triphenylbenzene and acenaphthene;

[0075] The R1 is selected from one or more groups shown in formulas (IV) to (VIII):

[0076]

[0077] In this invention, n = 1 to 50, can be n = 10 to 40, or can be n = 20 to 30.

[0078] In this invention, a = 1 to 6, p = 1 to 6, q = 1 to 6, can be a = 2 to 5, p = 2 to 5, q = 2 to 5, or a = 3 to 4, p = 3 to 4, q = 3 to 4.

[0079] This invention provides a method for preparing multi-block carbazole polyaromatic piperidine polymers as described above, comprising the following steps:

[0080] 1) After mixing Ar1 monomer, Ar2 monomer and solvent to obtain a solution, N-methyl-4-piperidinone monomer and 2,2,2-trifluoroacetophenone are added to obtain a mixed solution;

[0081] 2) After reacting the mixed solution obtained in the above steps under the action of an acid catalyst, a precipitant is added to precipitate the mixture, and the polymer is obtained.

[0082] 3) After mixing the polymer obtained in the above steps with the organic solvent again, a quaternization reaction is carried out under the action of a quaternization reagent, and after precipitation, a multi-block carbazole polyaromatic piperidine polymer is obtained.

[0083] The present invention first mixes Ar1 monomer, Ar2 monomer and solvent to obtain a solution, and then adds N-methyl-4-piperidinone monomer and 2,2,2-trifluoroacetophenone to obtain a mixed solution.

[0084] In this invention, the molar ratio of Ar1 monomer to Ar2 monomer is preferably (1-50):(99-50), more preferably (10-40):(90-60), and even more preferably (20-30):(80-70).

[0085] In this invention, the solvent preferably includes one or more of dimethyl sulfoxide, N-methylpyrrolidone, N,N-dimethylformamide, dichloromethane, diethyl ether, and tetrahydrofuran, more preferably dimethyl sulfoxide, N-methylpyrrolidone, N,N-dimethylformamide, dichloromethane, diethyl ether, or tetrahydrofuran.

[0086] In this invention, the solution preferably comprises a homogeneous solution or a heterogeneous solution.

[0087] In this invention, the ratio of the total molar number of Ar1 monomer and Ar2 monomer to the total molar number of N-methyl-4-piperidinone and 2,2,2-trifluoroacetophenone is preferably 1:(1 to 5), more preferably 1:(1.5 to 4.5), more preferably 1:(2 to 4), and even more preferably 1:(2.5 to 3.5).

[0088] In this invention, the molar ratio of N-methyl-4-piperidinone and 2,2,2-trifluoroacetophenone is preferably (9-5):(1-5), more preferably (8.5-5.5):(1.5-4.5), even more preferably (8-6):(2-4), and even more preferably (7.5-6.5):(2.5-3.5).

[0089] In this invention, the mixed solution obtained in the above steps is reacted under the action of an acid catalyst, and then a precipitant is added to precipitate the mixture, thereby obtaining a polymer.

[0090] In this invention, the acid catalyst preferably comprises solid acid and liquid acid.

[0091] In this invention, the solid acid preferably includes one or more of ZSM-5, Y-type molecular sieve and β-type molecular sieve, and more preferably ZSM-5, Y-type molecular sieve or β-type molecular sieve.

[0092] In this invention, the acid catalyst further includes a solid superacid.

[0093] In this invention, the solid superacid preferably includes Pt / SO4. 2- -ZrO2, S2O8 2- / CeO2-RF、CF3SO3H / ZrO2-Al2O3、SO4 2- / ZrO2、Pt-SO4 2- / ZrO 2- -Al2O3, SO4 2- / Fe2O3、SO4 2- / ZrO 2- -La2O3, SO4 2 - / SiO 2- -ZrO2, SO4 2- / M x Oy and SO4 2- / ZrO 2- One or more of NiO / Al2O3, more preferably Pt / SO4 2- -ZrO2, S2O8 2- / CeO2-RF、CF3SO3H / ZrO2-Al2O3、SO4 2- / ZrO2、Pt-SO4 2- / ZrO 2- -Al2O3, SO4 2- / Fe2O3、SO4 2- / ZrO 2- -La2O3, SO4 2 - / SiO 2- -ZrO2, SO4 2- / M x O y or SO4 2- / ZrO 2- NiO / Al2O3.

[0094] In this invention, the liquid acid preferably includes one or more of trifluoromethanesulfonic acid, trifluoroacetic acid and methanesulfonic acid, and more preferably trifluoromethanesulfonic acid, trifluoroacetic acid or methanesulfonic acid.

[0095] In this invention, the mass ratio of the solid acid to the sum of Ar1 and Ar2 is preferably 100:(50-100), more preferably 100:(60-90), and even more preferably 100:(70-80).

[0096] In this invention, the molar ratio of the liquid acid to the sum of Ar1 and Ar2 is preferably (5-13):1, more preferably (6-12):1, even more preferably (7-11):1, and even more preferably (8-10):1.

[0097] In this invention, the mass ratio of the solid superacid to the sum of Ar1 and Ar2 is preferably 100:(20-60), more preferably 100:(25-55), more preferably 100:(30-50), and even more preferably 100:(35-45).

[0098] In this invention, the reaction temperature is preferably -4 to 150°C, more preferably 40 to 150°C, and even more preferably 90 to 100°C.

[0099] In this invention, the reaction time is preferably 4 to 72 hours, more preferably 20 to 60 hours, and even more preferably 35 to 45 hours.

[0100] In this invention, the precipitant preferably includes one or more of methanol, NaOH and water, more preferably methanol, NaOH or water.

[0101] In this invention, step 2) preferably includes a washing step after precipitation.

[0102] In this invention, the washing process is preferably carried out by standing in a potassium carbonate solution or in water.

[0103] In this invention, the temperature at which the potassium carbonate solution is allowed to stand is preferably 25–80°C, more preferably 35–70°C, and even more preferably 45–60°C.

[0104] In this invention, the standing time in the potassium carbonate solution is preferably 5 to 72 hours, more preferably 20 to 60 hours, and even more preferably 35 to 45 hours.

[0105] In this invention, the temperature at which the water is left to stand is preferably 25–80°C, more preferably 35–70°C, and even more preferably 45–60°C.

[0106] In this invention, the preferred time for standing in water is 5 to 72 hours, more preferably 20 to 60 hours, and even more preferably 35 to 45 hours.

[0107] Finally, the polymer obtained in the above steps is mixed with an organic solvent again, and then subjected to a quaternization reaction under the action of a quaternizing agent. After precipitation, a multi-block carbazole polyaromatic piperidine polymer is obtained.

[0108] In this invention, the organic solvent preferably includes one or more of N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylformamide and N,N-dimethylacetamide, more preferably N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylformamide or N,N-dimethylacetamide.

[0109] In this invention, the remixing temperature is preferably 25-120°C, more preferably 45-100°C, and even more preferably 65-80°C.

[0110] In this invention, the quaternization reaction preferably includes one quaternization reaction or two quaternization reactions.

[0111] In this invention, the quaternizing agent for the primary quaternization reaction preferably includes iodomethane.

[0112] In this invention, the quaternizing agent for the two quaternization reactions preferably includes 1,6-dibromohexane, and one or more of trimethylamine, N-methylpiperidine, 4-vinylbenzyl chloride, and 4,4'-trimethylenebis(1-methylpiperidine), more preferably 1,6-dibromohexane, and trimethylamine, N-methylpiperidine, 4-vinylbenzyl chloride, and 4,4'-trimethylenebis(1-methylpiperidine). Specifically, the two quaternization reactions involve a first quaternization reaction with 1,6-dibromohexane to form a carbon chain with a terminal bromine group, followed by a second quaternization reaction with trimethylamine, N-methylpiperidine, quinine ring hydrochloride, or imidazole.

[0113] In this invention, the mass ratio of the polymer to the quaternizing agent is preferably 1:(1-5), more preferably 1:(1.5-4.5), more preferably 1:(2-4), and even more preferably 1:(2.5-3.5).

[0114] In this invention, the quaternization reaction time is preferably 6 to 72 hours, more preferably 20 to 60 hours, and even more preferably 35 to 45 hours.

[0115] In this invention, in step 4), the precipitation method preferably includes adding ethyl acetate for precipitation.

[0116] This invention provides the application of the multi-block carbazole polyaromatic piperidine polymer described in the above technical solutions or the multi-block carbazole polyaromatic piperidine polymer prepared by any of the preparation methods described in the above technical solutions in anion exchange membranes.

[0117] This invention provides an anion exchange membrane, wherein the anion exchange membrane is a multi-block carbazole polyarylene piperidine anion exchange membrane;

[0118] The anion exchange membrane includes an alkalized multi-block carbazole polyaromatic piperidine polymer.

[0119] The multi-block carbazole polyaromatic piperidine polymer is the multi-block carbazole polyaromatic piperidine polymer described in the above technical solutions or the multi-block carbazole polyaromatic piperidine polymer prepared by any of the preparation methods described in the above technical solutions.

[0120] In this invention, the multi-block carbazole-based polyarylene piperidine anion exchange membrane is preferably prepared by the following steps:

[0121] After mixing the multi-block carbazole polyaromatic piperidine polymer with a polar solution, a homogeneous solution of anion exchange resin is obtained. The homogeneous solution of anion exchange resin is then cast onto a substrate to form a film, which is then dried to form a membrane. After soaking in potassium hydroxide solution, the membrane is dried to obtain a multi-block carbazole polyaromatic piperidine anion exchange membrane in the form of hydroxide ions.

[0122] In this invention, the concentration of the homogeneous solution of the anion exchange resin is preferably 3 wt% to 25 wt%, more preferably 8 wt% to 20 wt%, and even more preferably 13 wt% to 15 wt%.

[0123] In this invention, the molding time is preferably 6 to 48 hours, more preferably 10 to 40 hours, and even more preferably 20 to 30 hours.

[0124] In this invention, the molding temperature is preferably 25-120°C, more preferably 45-100°C, and even more preferably 65-80°C.

[0125] In this invention, the soaking time is preferably 6 to 48 hours, more preferably 10 to 40 hours, and even more preferably 20 to 30 hours.

[0126] In this invention, the soaking temperature is preferably 25-80°C, more preferably 35-70°C, and even more preferably 45-60°C.

[0127] This invention provides the application of the multi-block carbazole polyaromatic piperidine polymer described in the above-mentioned technical solutions, the multi-block carbazole polyaromatic piperidine polymer prepared by any of the preparation methods described in any of the above-mentioned technical solutions, or the multi-block carbazole polyaromatic piperidine anion exchange membrane described in any of the above-mentioned technical solutions in the field of hydrogen production by water electrolysis.

[0128] This invention aims to complete and refine the overall technical solution, better preserve the structure of the multi-block carbazole-based polyaromatic piperidine polymer, and further improve the performance of the anion exchange membrane. Specifically, the invention includes the following: a multi-block carbazole-based polyaromatic piperidine polymer, its preparation method, and its applications; and a multi-block carbazole-based polyaromatic piperidine anion exchange membrane and its applications.

[0129] A first aspect of the present invention provides a polymer comprising the structural unit shown in formula (1).

[0130]

[0131] In the formula, Ar1 contains a carbazole aromatic group; Ar2 does not contain a carbazole aromatic group.

[0132] Wherein, Ar1 is any one or more of the following groups:

[0133]

[0134] Wherein, Ar2 is one or more of biphenyl, p-terphenyl, p-tetraphenyl, m-terphenyl, diphenylmethane, diphenylethane, 1,3,5-triphenylbenzene, and acenaphthene:

[0135]

[0136] Where R1 is:

[0137]

[0138] A second aspect of the present invention provides a method for preparing a multi-block carbazole-based polyarylene piperidine anion exchange membrane:

[0139] (1) Under normal temperature conditions, Ar1 and Ar2 monomers are first dissolved in a solvent at a molar ratio of 1:99 to 50:50 to form a homogeneous or heterogeneous solution; then, N-methyl-4-piperidinone monomer and 2,2,2-trifluoroacetophenone are added to the solvent and stirred to dissolve. The sum of the molar ratios of Ar1 and Ar2 to N-methyl-4-piperidinone and 2,2,2-trifluoroacetophenone is 1:1 to 1:5, the molar ratio of N-methyl-4-piperidinone to 2,2,2-trifluoroacetophenone is 9:1 to 5:5, and the concentration of all monomers in the solution is 5% to 50%.

[0140] (2) In an environment of -4 to 150°C, add one or more of a solid acid, a solid superacid, or a liquid acid to the solution in step (1), wherein the mass ratio of the solid acid to the sum of Ar1 and Ar2 is 1:(50 to 100) wt%, the mass ratio of the solid superacid to the sum of Ar1 and Ar2 is 1:(20 to 60) wt%, and the molar ratio of the liquid acid to the sum of Ar1 and Ar2 is 5:1 to 13:1, and then react at this temperature for 4 to 72 h;

[0141] (3) After the reaction is complete, the solution is first filtered. The solid acid or solid superacid is reserved for the next use. Then the solution from step (2) is poured into methanol, NaOH, deionized water or one or more to obtain a fibrous solid. It is placed in 1M potassium carbonate solution at 25-80℃ for 5-72 hours. Then it is placed in deionized water at 25-80℃ for 5-72 hours. The obtained polymer is dried in a vacuum oven at 60-180℃ for later use.

[0142] (4) Dissolve the polymer dried in step (3) in a solvent at 25-120°C, add 1-5 times the polymer mass of iodomethane or tertiary amine compound to the solvent, and react at room temperature for 6-72 h.

[0143] (5) After the reaction is complete, the solution from step (4) is added dropwise to ethyl acetate to precipitate, and washed repeatedly with ethyl acetate and deionized water respectively. The solution is then dried in a vacuum oven at 60-180°C to obtain anion exchange resin.

[0144] (6) Finally, the anion exchange resin from step (5) is dissolved in a polar solution to form a homogeneous solution of 3-25 wt% anion exchange resin. The solution is then directly cast onto a PET substrate using a glass plate or an automatic casting machine and dried at 25-120°C for 6-48 hours to form a film.

[0145] (7) Soak in 1M KOH at 25-80℃ for 6-48h, dry in a vacuum environment, and then store the membrane in a vacuum environment for later use to obtain a carbazole polyaromatic piperidine anion exchange membrane in hydroxide form.

[0146] Specifically, the solvent in step (1) is one or more of dimethyl sulfoxide, N-methylpyrrolidone, N,N-dimethylformamide, dichloromethane, diethyl ether, and tetrahydrofuran.

[0147] Specifically, in step (2), the solid acid is one or more of ZSM-5 (silicon-to-aluminum ratio of 5 to 40), Y-type molecular sieve (silicon-to-aluminum ratio of 3 to 6), and β-type molecular sieve (silicon-to-aluminum ratio of 6 to 40).

[0148] Specifically, the solid superacid is Pt / SO4. 2- -ZrO2, S2O8 2- / CeO2-RF、CF3SO3H / ZrO2-Al2O3、SO4 2- / ZrO2、Pt-SO4 2- / ZrO 2- -Al2O3, SO4 2- / Fe2O3、SO4 2- / ZrO 2- -La2O3, SO4 2 - / SiO 2- -ZrO2, SO4 2- / M x O y SO4 2- / ZrO 2- One or more of NiO / Al2O3.

[0149] Specifically, the liquid acid is one or more of trifluoromethanesulfonic acid, trifluoroacetic acid, and methanesulfonic acid.

[0150] Specifically, the solvent in step (4) is one or more of N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylformamide, and N,N-dimethylacetamide.

[0151] Specifically, different carbazole monomers are introduced into the aromatic hydrocarbon and piperidinone polymer, and a fluorinated hydrophobic compound is also introduced, wherein the fluorinated hydrophobic compound is 2,2,2-trifluoroacetophenone.

[0152] The carbazole monomer Ar1 is any one of the following groups, preferably N-methylcarbazole;

[0153]

[0154] Specifically, the Ar2 is selected from one or more of the following: biphenyl, p-terphenyl, p-tetraphenyl, m-terphenyl, diphenylmethane, diphenylethane, 1,3,5-triphenylbenzene and acenaphthene, preferably p-terphenyl.

[0155]

[0156] Specifically, in step (1), the optimal molar ratio of Ar1:Ar2 is 10:90 to 30:70; the optimal molar ratio of the sum of Ar1 and Ar2 to the sum of N-methyl-4-piperidinone and 2,2,2-trifluoroacetophenone is 1:1 to 1:3; the optimal molar ratio of N-methyl-4-piperidinone to 2,2,2-trifluoroacetophenone is 9:1 to 7:3; and the optimal concentration of the sum of all monomers in the solution is 15% to 25%.

[0157] Specifically, in step (2), the preferred silica-to-alumina ratio of ZSM-5 molecular sieve in the solid acid is 5-20, the preferred silica-to-alumina ratio of Y-type molecular sieve is 3-4, and the preferred silica-to-alumina ratio of β-type molecular sieve is 6-20. The optimal mass ratio of the solid acid to the sum of Ar1 and Ar2 is 1:(70-100)wt%, and the optimal mass ratio of the solid superacid to the sum of Ar1 and Ar2 is 1:(30-60)wt%. The preferred liquid acid is trifluoromethanesulfonic acid, and the optimal molar ratio of trifluoromethanesulfonic acid to the sum of Ar1 and Ar2 is 7:1-13:1.

[0158] Specifically, in step (2), the reaction temperature is 0 to 120°C and the reaction time is 8 to 48 hours.

[0159] Specifically, in step (3), the solution is preferably methanol, the reaction temperature is 40-80℃, the reaction time is 8-24h, and the drying temperature is preferably 60-120℃.

[0160] The present invention also provides an anion exchange membrane prepared by the method of the present invention described above. Specifically, the anion exchange membrane contains a polymer with the following structure:

[0161]

[0162] This invention also provides applications of the method described above for preparing anion exchange membranes.

[0163] The present invention provides a multi-block carbazole-based polyaromatic piperidine polymer and its preparation method and application, as well as an anion exchange membrane and its application, particularly relating to a multi-block carbazole-based polyaromatic piperidine anion exchange membrane and its application.

[0164] This invention specifically designs a multi-block carbazole-based polyaromatic piperidine polymer with a specific structure and its preparation method. This invention introduces carbazole aryl groups into the polymer backbone of aromatic hydrocarbons and piperidine ketones. Since the benzene ring in the carbazole aryl group lacks internal rotational function, it effectively improves the conductivity of the anion exchange membrane. Introducing fluorinated hydrophobic compounds into the polyaromatic hydrocarbon and piperidine ketone backbone promotes the microphase separation structure of the anion exchange membrane, thereby increasing the ion transport rate. The multi-block carbazole-based polyaromatic piperidine anion exchange membrane exhibits excellent chemical stability, film-forming properties, conductivity, and mechanical strength. This anion exchange membrane demonstrates excellent performance and durability in alkaline water electrolysis. The preparation process provided by this invention reduces or eliminates the use of traditional liquid acid catalysts, using solid acid and solid superacid catalysts, which can be reused.

[0165] The preparation process of the multi-block carbazole-based polyaromatic piperidine polymer provided by this invention allows for the complete replacement of liquid acid with solid acid or solid superacid catalyst. However, it requires the selection of high-boiling-point solvents, extended reaction time, and increased reaction temperature during the preparation process. In low-boiling-point solvents and at low temperatures, the addition of solid acid can reduce the amount of liquid acid used by 30%, and the addition of solid superacid can reduce the amount of liquid acid used by 50%. Furthermore, the solid acid and solid superacid catalyst can be reused. The preparation method is simple and has low production costs. The multi-block carbazole-based polyaromatic piperidine polymer prepared by this invention exhibits excellent performance as anion exchange membranes, is suitable for industrial casting, has high mechanical strength, and can be applied to alkaline fuel cells, electrodialysis, and anion exchange membrane water electrolysis for hydrogen production.

[0166] This invention introduces carbazole-based aryl compounds and fluorinated hydrophobic compounds into the polymer backbone of aromatic hydrocarbons and piperidinones, promoting the microphase separation structure of the anion exchange membrane and improving ion transport capacity and alkaline stability. Furthermore, this invention is the first to employ a green preparation method using solid acid and a solid superacid catalyst, reducing the amount of liquid acid used and allowing for the reuse of the solid catalyst. The anion exchange membrane prepared by this invention not only exhibits excellent mechanical stability but also superior electrical conductivity (188 mS / cm @ 90℃); after immersion in 1M KOH solution at 80℃ for 2000 h, the conductivity loss is <5%, demonstrating extremely high alkali resistance. Further, when the anion exchange membrane is assembled into an alkaline water electrolysis membrane electrode, it operates stably for 1000 h without a significant voltage increase. The preparation method of this invention is simple, environmentally friendly, and low-cost. The anion exchange membrane prepared using this invention can be applied in fields such as alkaline anion exchange membrane water electrolysis for hydrogen production, alkaline fuel cells, and carbon dioxide catalytic reduction.

[0167] Experimental results show that the multi-block carbazole-based polyarylene piperidine anion exchange membrane prepared in this invention has excellent OH... -The conductivity (188 mS / cm @ 90℃) and alkali resistance (conductivity loss < 5% in 1M KOH solution at 80℃ for 2000 h) were excellent. The alkaline water electrolysis membrane electrode assembly (AEMWE) composed of multi-block carbazole polyaromatic piperidine anion exchange membrane operated stably for 1000 h without voltage rise.

[0168] To further illustrate the present invention, the following detailed description, in conjunction with embodiments, describes a multi-block carbazole polyaromatic piperidine polymer and its preparation method, applications, and an anion exchange membrane and its applications provided by the present invention. However, it should be understood that these embodiments are implemented under the premise of the technical solution of the present invention, and provide detailed implementation methods and specific operating procedures, only to further illustrate the features and advantages of the present invention, and not to limit the scope of protection of the claims of the present invention. The scope of protection of the present invention is not limited to the following embodiments.

[0169] Example 1

[0170] A method for preparing a multi-block carbazole-based polyarylene piperidine anion exchange membrane, the specific steps of which include:

[0171] (1) Under normal temperature conditions, N-methylcarbazole and p-terphenyl monomers were first dissolved in dichloromethane solvent at a molar ratio of 10:90 to form a heterogeneous solution; then, N-methyl-4-piperidinone monomers and 2,2,2-trifluoroacetophenone were added to the dichloromethane solvent and stirred to dissolve. The sum of the molar ratios of N-methylcarbazole and p-terphenyl to N-methyl-4-piperidinone and 2,2,2-trifluoroacetophenone was 1:1, the molar ratio of N-methyl-4-piperidinone to 2,2,2-trifluoroacetophenone was 9:1, and the concentration of all monomers in the solution was 10%.

[0172] (2) At -4℃, trifluoromethanesulfonic acid was added to the solution in step (1), with a molar ratio of trifluoromethanesulfonic acid to the sum of Ar1 and Ar2 of 8:1, and then the reaction was carried out at this temperature for 8 hours.

[0173] (3) After the reaction is complete, the solution from step (2) is poured into methanol to obtain a fibrous solid. It is placed in 1M potassium carbonate solution at 60°C for 12 hours, and then placed in deionized water at 60°C for 12 hours. The resulting polymer is dried in a vacuum oven at 60°C for 24 hours before use.

[0174] (4) Dissolve the polymer dried in step (3) in dimethyl sulfoxide solvent at 60°C, add iodomethane with a polymer mass of 1 times to the solvent, and react at room temperature for 24 h.

[0175] (5) After the reaction is complete, the solution from step (4) is added dropwise to ethyl acetate to precipitate, and washed repeatedly with ethyl acetate and deionized water, respectively. The solution is then placed in a vacuum oven at 60°C and dried for 24 hours to obtain anion exchange resin.

[0176] (6) Finally, the anion exchange resin from step (5) is dissolved in a polar solution to form a 5 wt% homogeneous anion exchange resin solution, which is then directly cast onto a PET substrate and placed at 80°C for 12 h, and then placed at 120°C for 2 h to dry and form a film.

[0177] (7) Soak in 1M KOH at 80℃ for 24h, dry in vacuum at 60℃ for 10h, and then store the membrane in a vacuum environment for later use to obtain a carbazole polyaromatic piperidine anion exchange membrane in hydroxide form.

[0178] Example 2

[0179] (1) Under normal temperature conditions, N-methylcarbazole and p-terphenyl monomers were first dissolved in dichloromethane solvent at a molar ratio of 20:80 to form a heterogeneous solution; then, N-methyl-4-piperidinone monomers and 2,2,2-trifluoroacetophenone were added to the dichloromethane solvent and stirred to dissolve. The sum of Ar1 and Ar2 and the molar ratio of N-methyl-4-piperidinone and 2,2,2-trifluoroacetophenone were 1:1, the molar ratio of N-methyl-4-piperidinone to 2,2,2-trifluoroacetophenone was 9:1, and the concentration of all monomers in the solution was 15%.

[0180] (2) The other steps are the same as in Example 1.

[0181] Example 3

[0182] (1) Under normal temperature conditions, N-methylcarbazole and p-terphenyl monomers were first dissolved in dichloromethane solvent at a molar ratio of 30:70 to form a heterogeneous solution; then, N-methyl-4-piperidinone monomers and 2,2,2-trifluoroacetophenone were added to the dichloromethane solvent and stirred to dissolve. The sum of the molar ratios of N-methylcarbazole and p-terphenyl to N-methyl-4-piperidinone and 2,2,2-trifluoroacetophenone was 1:1, the molar ratio of N-methyl-4-piperidinone to 2,2,2-trifluoroacetophenone was 9:1, and the concentration of all monomers in the solution was 20%.

[0183] Example 4

[0184] (1) Under normal temperature conditions, N-methylcarbazole and p-terphenyl monomers were first dissolved in dichloromethane solvent at a molar ratio of 40:60 to form a heterogeneous solution; then, N-methyl-4-piperidinone monomers and 2,2,2-trifluoroacetophenone were added to the dichloromethane solvent and stirred to dissolve. The sum of the molar ratios of N-methylcarbazole and p-terphenyl to N-methyl-4-piperidinone and 2,2,2-trifluoroacetophenone was 1:1, the molar ratio of N-methyl-4-piperidinone to 2,2,2-trifluoroacetophenone was 9:1, and the concentration of all monomers in the solution was 20%.

[0185] (2) The other steps are the same as in Example 1.

[0186] Example 5

[0187] (1) Under normal temperature conditions, N-methylcarbazole and p-terphenyl monomers were first dissolved in dichloromethane solvent at a molar ratio of 10:90 to form a heterogeneous solution; then, N-methyl-4-piperidinone monomers and 2,2,2-trifluoroacetophenone were added to the dichloromethane solvent and stirred to dissolve. The sum of the molar ratios of N-methylcarbazole and p-terphenyl to N-methyl-4-piperidinone and 2,2,2-trifluoroacetophenone was 1:3, the molar ratio of N-methyl-4-piperidinone to 2,2,2-trifluoroacetophenone was 9:1, and the concentration of all monomers in the solution was 10%.

[0188] (2) The other steps are the same as in Example 1.

[0189] Example 6

[0190] (1) Under normal temperature conditions, N-methylcarbazole and p-terphenyl monomers were first dissolved in dichloromethane solvent at a molar ratio of 10:90 to form a heterogeneous solution; then, N-methyl-4-piperidinone monomers and 2,2,2-trifluoroacetophenone were added to the dichloromethane solvent and stirred to dissolve. The sum of the molar ratios of N-methylcarbazole and p-terphenyl to N-methyl-4-piperidinone and 2,2,2-trifluoroacetophenone was 1:5, the molar ratio of N-methyl-4-piperidinone to 2,2,2-trifluoroacetophenone was 9:1, and the concentration of all monomers in the solution was 10%.

[0191] (2) The other steps are the same as in Example 1.

[0192] Example 7

[0193] (1) Under normal temperature conditions, N-methylcarbazole and p-terphenyl monomers were first dissolved in dichloromethane solvent at a molar ratio of 10:90 to form a heterogeneous solution; then, N-methyl-4-piperidinone monomers and 2,2,2-trifluoroacetophenone were added to the dichloromethane solvent and stirred to dissolve. The sum of the molar ratios of N-methylcarbazole and p-terphenyl to N-methyl-4-piperidinone and 2,2,2-trifluoroacetophenone was 1:1, the molar ratio of N-methyl-4-piperidinone to 2,2,2-trifluoroacetophenone was 5:1, and the concentration of all monomers in the solution was 10%.

[0194] Example 8

[0195] (1) Under normal temperature conditions, N-methylcarbazole and p-terphenyl monomers were first dissolved in dichloromethane solvent at a molar ratio of 10:90 to form a heterogeneous solution; then, N-methyl-4-piperidinone monomers and 2,2,2-trifluoroacetophenone were added to the dichloromethane solvent and stirred to dissolve. The sum of the molar ratios of N-methylcarbazole and p-terphenyl to N-methyl-4-piperidinone and 2,2,2-trifluoroacetophenone was 1:1, the molar ratio of N-methyl-4-piperidinone to 2,2,2-trifluoroacetophenone was 3:1, and the concentration of all monomers in the solution was 10%.

[0196] Example 9

[0197] (1) Under normal temperature conditions, N-methylcarbazole and p-terphenyl monomers were first dissolved in dichloromethane solvent at a molar ratio of 10:90 to form a heterogeneous solution; then, N-methyl-4-piperidinone monomers and 2,2,2-trifluoroacetophenone were added to the dichloromethane solvent and stirred to dissolve. The sum of the molar ratios of N-methylcarbazole and p-terphenyl to N-methyl-4-piperidinone and 2,2,2-trifluoroacetophenone was 1:1, the molar ratio of N-methyl-4-piperidinone to 2,2,2-trifluoroacetophenone was 1:1, and the concentration of all monomers in the solution was 10%.

[0198] (2) The other steps are the same as in Example 1.

[0199] Example 10

[0200] (1) Add N-methylpiperidine, which is 1 times the polymer mass, to the mixed solution after quaternization of iodomethane in step (3) and react at room temperature for 24 h.

[0201] (2) The other steps are the same as in Example 1.

[0202] Example 11

[0203] (1) Add one times the polymer mass of trimethylamine to the mixed solution after quaternization of iodomethane in step (3) and react at room temperature for 24 h.

[0204] (2) The other steps are the same as in Example 1.

[0205] Example 12

[0206] (1) Add 4-vinylbenzyl chloride, which is 1 times the polymer mass, to the mixed solution after quaternization of iodomethane in step (3) and react at room temperature for 24 h.

[0207] (2) The other steps are the same as in Example 1.

[0208] Example 13

[0209] (1) Add 4,4'-trimethylenebis(1-methylpiperidine) at a polymer mass of 1 to the mixed solution after quaternization with iodomethane in step (3), and react at room temperature for 24 h.

[0210] (2) The other steps are the same as in Example 1.

[0211] Example 14

[0212] (1) In step (2), at 120°C, the dichloromethane solution in step (1) is changed to dimethyl sulfoxide, and ZSM-5 molecular sieve is added. The mass ratio of ZSM-5 molecular sieve (silicon-aluminum ratio of 20) to the sum of Ar1 and Ar2 is 1:60wt%, and then the reaction is carried out at this temperature for 24h.

[0213] (2) The other steps are the same as in Example 1.

[0214] Example 15

[0215] (1) In step (2), at 120°C, the dichloromethane solution in step (1) is replaced with dimethyl sulfoxide, and SO4 is added. 2- / ZrO2,SO4 2- The mass ratio of ZrO2 to the sum of Ar1 and Ar2 is 1:30wt%, and then the reaction is carried out at this temperature for 24 hours.

[0216] (2) The other steps are the same as in Example 1.

[0217] Example 16

[0218] (1) In step (2), at 120°C, the dichloromethane solution in step (1) is replaced with dimethyl sulfoxide, and ZSM-5 molecular sieve (silicon-to-aluminum ratio of 20) and SO4 are added. 2- / ZrO2, ZSM-5 molecular sieve (silicon-to-aluminum ratio of 20) and SO4 2- The mass ratio of ZrO2 to the sum of Ar1 and Ar2 is 1:60wt%, and the ZSM-5 molecular sieve (silicon-to-aluminum ratio of 20) is mixed with SO4.2- The mass ratio of ZrO2 to ZrO2 is 2:1, and the reaction is carried out at this temperature for 24 hours.

[0219] (2) The other steps are the same as in Example 1.

[0220] Example 17

[0221] (1) In step (2), at 120°C, the dichloromethane solution in step (1) was replaced with dimethyl sulfoxide, and ZSM-5 molecular sieve filtered and cleaned in Example 14 and SO4 were added. 2- / ZrO2, and then react at that temperature for 24 hours.

[0222] Example 18

[0223] (1) In step (2), at -4°C, the dichloromethane solution in step (1) is replaced with dimethyl sulfoxide, and trifluoromethanesulfonic acid and SO4 are added. 2- The molar ratio of ZrO2, trifluoromethanesulfonic acid, and the sum of Ar1 and Ar2 is 4:1, SO4 2- The mass ratio of ZrO2 to the sum of Ar1 and Ar2 is 1:10wt%, and the mixture is then reacted at this temperature for 48 hours.

[0224] Example 19

[0225] (1) In step (2), at -4°C, the dichloromethane solution in step (1) is changed to dimethyl sulfoxide, and trifluoromethanesulfonic acid and ZSM-5 molecular sieve (silicon-to-aluminum ratio of 20) are added. The molar ratio of trifluoromethanesulfonic acid to the sum of Ar1 and Ar2 is 4:1, and the mass ratio of ZSM-5 molecular sieve (silicon-to-aluminum ratio of 20) to the sum of Ar1 and Ar2 is 1:30wt%. The reaction is then carried out at this temperature for 48h.

[0226] (2) The other steps are the same as in Example 1.

[0227] Comparative Example 1

[0228] (1) Under normal temperature conditions, the terphenyl monomer is first dissolved in dichloromethane solvent to form a heterogeneous solution; then, N-methyl-4-piperidone monomer is added to dichloromethane solvent, the molar ratio of terphenyl to N-methyl-4-piperidone is 1:1, and the concentration of all monomers in the solution is 10%.

[0229] (2) Trifluoromethanesulfonic acid was added to the solution in step (1) at -4℃, with a molar ratio of trifluoromethanesulfonic acid to p-terphenyl of 8:1, and then the reaction was carried out at this temperature for 8 hours.

[0230] (3) After the reaction is complete, the solution from step (2) is poured into methanol to obtain a fibrous solid. It is placed in 1M potassium carbonate solution at 60°C for 12 hours, and then placed in deionized water at 60°C for 12 hours. The resulting polymer is dried in a vacuum oven at 60°C for 24 hours before use.

[0231] (4) Dissolve the polymer dried in step (3) in dimethyl sulfoxide solvent at 60°C, add iodomethane with a polymer mass of 1 times to the solvent, and react at room temperature for 24 h.

[0232] (5) After the reaction is complete, the solution from step (4) is added dropwise to ethyl acetate to precipitate, and washed repeatedly with ethyl acetate and deionized water, respectively. The solution is then placed in a vacuum oven at 60°C and dried for 24 hours to obtain anion exchange resin.

[0233] (6) Finally, the anion exchange resin from step (5) is dissolved in a polar solution to form a 5wt% homogeneous anion exchange resin solution, which is then directly cast onto a PET substrate and placed at 80°C for 12 hours, and then placed at 120°C for 2 hours to dry into a film.

[0234] (7) Soak in 1M KOH at 80℃ for 24h, dry in vacuum at 60℃ for 10h, and then store the membrane in a vacuum environment for later use to obtain a carbazole polyaromatic piperidine anion exchange membrane in hydroxide form.

[0235] Comparative Example 2

[0236] (1) Under normal temperature conditions, N-methylcarbazole and p-terphenyl monomers were first dissolved in dichloromethane solvent at a molar ratio of 10:90 to form a heterogeneous solution; then, N-methyl-4-piperidinone monomer was added to dichloromethane solvent and stirred to dissolve. The sum of the molar ratios of N-methylcarbazole and p-terphenyl to N-methyl-4-piperidinone was 1:1, and the concentration of all monomers in the solution was 10%.

[0237] (2) Trifluoromethanesulfonic acid was added to the solution in step (1) at -4℃. The molar ratio of trifluoromethanesulfonic acid to N-methylcarbazole and p-terphenyl was 8:1. The reaction was carried out at this temperature for 8 hours.

[0238] (3) After the reaction is complete, the solution from step (2) is poured into methanol to obtain a fibrous solid. It is placed in 1M potassium carbonate solution at 60°C for 12 hours, and then placed in deionized water at 60°C for 12 hours. The resulting polymer is dried in a vacuum oven at 60°C for 24 hours before use.

[0239] (4) Dissolve the polymer dried in step (3) in dimethyl sulfoxide solvent at 60°C, add iodomethane with a polymer mass of 1 times to the solvent, and react at room temperature for 24 h.

[0240] (5) After the reaction is complete, the solution from step (4) is added dropwise to ethyl acetate to precipitate, and washed repeatedly with ethyl acetate and deionized water, respectively. The solution is then placed in a vacuum oven at 60°C and dried for 24 hours to obtain anion exchange resin.

[0241] (6) Finally, the anion exchange resin from step (5) is dissolved in a polar solution to form a 5wt% homogeneous anion exchange resin solution, which is then directly cast onto a PET substrate and placed at 80°C for 12 hours, and then placed at 120°C for 2 hours to dry into a film.

[0242] (7) Soak in 1M KOH at 80℃ for 24h, dry in vacuum at 60℃ for 10h, and then store the membrane in a vacuum environment for later use to obtain a carbazole polyaromatic piperidine anion exchange membrane in hydroxide form.

[0243] Comparative Example 3

[0244] (1) Under normal temperature conditions, the terphenyl monomer is first dissolved in dichloromethane solvent to form a heterogeneous solution; then, N-methyl-4-piperidinone and 2,2,2-trifluoroacetophenone monomers are added to the dichloromethane solvent and stirred to dissolve. The sum of the molar ratios of terphenyl to N-methyl-4-piperidinone and 2,2,2-trifluoroacetophenone is 1:1, and the sum of the concentrations of all monomers in the solution is 10%.

[0245] (2) Trifluoromethanesulfonic acid was added to the solution in step (1) at -4℃, with a molar ratio of trifluoromethanesulfonic acid to p-terphenyl of 8:1, and then the reaction was carried out at this temperature for 8 hours.

[0246] (3) After the reaction is complete, the solution from step (2) is poured into methanol to obtain a fibrous solid. It is placed in 1M potassium carbonate solution at 60°C for 12 hours, and then placed in deionized water at 60°C for 12 hours. The resulting polymer is dried in a vacuum oven at 60°C for 24 hours before use.

[0247] (4) Dissolve the polymer dried in step (3) in dimethyl sulfoxide solvent at 60°C, add iodomethane with a polymer mass of 1 times to the solvent, and react at room temperature for 24 h.

[0248] (5) After the reaction is complete, the solution from step (4) is added dropwise to ethyl acetate to precipitate, and washed repeatedly with ethyl acetate and deionized water, respectively. The solution is then placed in a vacuum oven at 60°C and dried for 24 hours to obtain anion exchange resin.

[0249] (6) Finally, the anion exchange resin from step (5) is dissolved in a polar solution to form a 5 wt% homogeneous anion exchange resin solution, which is then directly cast onto a PET substrate and placed at 80°C for 12 h, and then placed at 120°C for 2 h to dry and form a film.

[0250] (7) Soak in 1M KOH at 80℃ for 24h, dry in vacuum at 60℃ for 10h, and then store the membrane in a vacuum environment for later use to obtain a carbazole polyaromatic piperidine anion exchange membrane in hydroxide form.

[0251] Membrane mechanical property test (tensile stress, elongation at break): Cut a 1cm×3cm sample of the anion exchange membrane prepared in step (6), place it in deionized water for 24 hours, wipe off the surface moisture quickly, and then test it. The test was conducted using a universal testing machine at 25℃ and a tensile rate of 5mm / min.

[0252] Membrane conductivity test (conductivity): Cut a 1cm×3cm sample of the anion exchange membrane prepared in step (6), place it in 1M KOH solution at 60℃ for 12h, then wash it several times with deionized water, and test it at 90℃ using an electrochemical workstation.

[0253] Moisture content and swelling rate tests: Cut 1cm × 3cm anion exchange membrane samples prepared in step (6) and dry them in a vacuum at 60°C to ensure that residual solvent and water are completely removed. Measure the length L of the dried samples. dry (mm), Thickness T dry (mm) and mass W dry (g). The membrane was then immersed in deionized water at 80℃ for 2 hours, and the membrane length L after immersion was measured. wet (mm), Thickness T wet (mm) and mass W we t(g).

[0254] The final formula for calculating the water absorption rate of the membrane is as follows:

[0255]

[0256] Formula for calculating the swelling ratio of a membrane:

[0257]

[0258] Alkali resistance stability test: Cut 1cm × 3cm anion exchange membrane samples prepared in step (6) and immerse the samples in 1 mol / L NaOH solution at room temperature for 2 days to ensure complete replacement with OH. -For the anion exchange membrane, the membrane was removed from the NaOH solution and repeatedly washed with deionized water to remove any residual solution. The membrane was then immersed in a 1 mol / L NaOH solution at 80°C. Samples were taken out at regular intervals to test their conductivity, and the conductivity decay rate after 2000 hours was finally determined.

[0259] Electrolysis performance test: Cut a 2cm × 2cm anion exchange membrane prepared in step (6) and place it in 1M KOH solution at 80℃ for 24h, then wash it several times with deionized water. Test the membrane electrode under the following conditions: 1M KOH, 80℃, 1A / cm. 2 Commercially available nickel foam was used as the anode and cathode catalyst.

[0260] See Table 1, which shows the performance data of the anion exchange membranes prepared in the embodiments and comparative examples of the present invention.

[0261] Table 1

[0262]

[0263]

[0264] See Table 2, which shows the performance data of the anion exchange membranes prepared in the embodiments and comparative examples of the present invention.

[0265] Table 2

[0266]

[0267]

[0268]

[0269] The foregoing has provided a detailed description of a multi-block carbazole-based polyarylene piperidine anion exchange membrane and its applications. Specific examples have been used to illustrate the principles and implementation methods of the invention. The descriptions of these embodiments are merely illustrative of the method and core ideas of the invention, including the best mode, and are intended to enable any person skilled in the art to practice the invention, including manufacturing and using any device or system, and implementing any combined method. It should be noted that those skilled in the art can make various improvements and modifications to the invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims. The scope of protection of this patent is defined by the claims and may include other embodiments conceived by those skilled in the art. If these other embodiments have structural elements that are not different from the wording of the claims, or if they include equivalent structural elements that are not substantially different from the wording of the claims, then these other embodiments should also be included within the scope of the claims.

Claims

1. A multi-block carbazole-based polyaromatic piperidine polymer, characterized in that, The multi-block carbazole polyaromatic piperidine polymer comprises the structural unit shown in formula (I): （I）； Where n = 1~50; in formula (I), Ar1 contains carbazole aromatic groups, and Ar2 does not contain carbazole aromatic groups; The Ar1 is selected from the groups shown in formula (II) and / or formula (III): (II), (III)) Where a = 1~6, p = 1~6, q = 1~6; The Ar2 is selected from one or more of biphenyl, p-terphenyl, p-tetraphenyl, m-terphenyl, diphenylmethane, diphenylethane, 1,3,5-triphenylbenzene and acenaphthene; The R1 is selected from one or more of the groups shown in formulas (IV) to (VII): -CH3(IV) (V) (VI); (VII); The preparation method of the multi-block carbazole polyaromatic piperidine polymer includes the following steps: 1) After mixing Ar1 monomer, Ar2 monomer and solvent to obtain a solution, N-methyl-4-piperidinone monomer and 2,2,2-trifluoroacetophenone are added to obtain a mixed solution; The molar ratio of Ar1 monomer to Ar2 monomer is (1~50):(99~50). The ratio of the total molar number of Ar1 monomer and Ar2 monomer to the total molar number of N-methyl-4-piperidinone and 2,2,2-trifluoroacetophenone is 1:(1~5). The molar ratio of N-methyl-4-piperidinone and 2,2,2-trifluoroacetophenone is (9~5):(1~5). 2) After reacting the mixed solution obtained in the above steps under the action of an acid catalyst, a precipitant is added to precipitate the mixture, and the polymer is obtained. The acid catalyst includes a solid acid; The solid acid includes one or more of ZSM-5, Y-type molecular sieve, and β-type molecular sieve; The mass ratio of the solid acid to the sum of Ar1 and Ar2 is 100:(50~100). 3) After mixing the polymer obtained in the above steps with the organic solvent again, a quaternization reaction is carried out under the action of a quaternization reagent, and after precipitation, a multi-block carbazole polyaromatic piperidine polymer is obtained.

2. The multi-block carbazole polyaromatic piperidine polymer according to claim 1, characterized in that, The solvent includes one or more of dimethyl sulfoxide, N-methylpyrrolidone, N,N-dimethylformamide, dichloromethane, diethyl ether, and tetrahydrofuran; The solution may be a homogeneous solution or a heterogeneous solution.

3. The multi-block carbazole polyaromatic piperidine polymer according to claim 1, characterized in that, The acid catalyst includes a liquid acid; The acid catalyst also includes a solid superacid; The solid superacid includes Pt / SO4. 2- -ZrO2, S2O8 2- / CeO2-RF、CF3SO3H / ZrO2-Al2O3、SO4 2- / ZrO2、Pt-SO4 2- / ZrO 2- -Al2O3, SO4 2- / Fe2O3、SO4 2- / ZrO 2- -La2O3 and SO4 2 - / SiO 2- One or more of -ZrO2; The liquid acid includes one or more of trifluoromethanesulfonic acid, trifluoroacetic acid, and methanesulfonic acid; The molar ratio of the liquid acid to the sum of Ar1 and Ar2 is (5~13):1; The mass ratio of the solid superacid to the sum of Ar1 and Ar2 is 100:(20~60).

4. The multi-block carbazole polyaromatic piperidine polymer according to claim 1, characterized in that, The precipitant includes one or more of methanol, NaOH, and water; The precipitation step in step 2) also includes a washing step; The washing process specifically involves standing in a potassium carbonate solution and standing in water.

5. The multi-block carbazole polyaromatic piperidine polymer according to claim 4, characterized in that, The temperature at which the potassium carbonate solution is allowed to stand is 25~80℃; The standing time in the potassium carbonate solution is 5~72 h; The temperature at which the water is kept still is 25~80℃; The time for standing in water is 5 to 72 hours.

6. The multi-block carbazole polyaromatic piperidine polymer according to claim 1, characterized in that, The organic solvent includes one or more of N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylformamide and N,N-dimethylacetamide; The remixing temperature is 25~120℃; The quaternization reaction includes a single quaternization reaction or two quaternization reactions; The mass ratio of the polymer to the quaternizing agent is 1:(1~5); The quaternization reaction takes 6-72 h; In step 4), precipitation can be carried out by adding ethyl acetate.

7. The application of the multi-block carbazole polyaromatic piperidine polymer according to any one of claims 1 to 6 in anion exchange membranes.

8. An anion exchange membrane, characterized in that, The anion exchange membrane is a multi-block carbazole polyaromatic piperidine anion exchange membrane; The anion exchange membrane includes an alkalized multi-block carbazole polyaromatic piperidine polymer. The multiblock carbazole polyaromatic piperidine polymer is the multiblock carbazole polyaromatic piperidine polymer according to any one of claims 1 to 6.

9. The anion exchange membrane according to claim 8, characterized in that, The multi-block carbazole-based polyaromatic piperidine anion exchange membrane was prepared by the following steps: After mixing the multi-block carbazole polyaromatic piperidine polymer with a polar solution, a homogeneous solution of anion exchange resin is obtained. The homogeneous solution of anion exchange resin is then cast onto a substrate to form a film, which is then dried to form a membrane. After soaking in potassium hydroxide solution, the membrane is dried to obtain a multi-block carbazole polyaromatic piperidine anion exchange membrane in the form of hydroxide ions. The concentration of the homogeneous solution of the anion exchange resin is 3wt%~25wt%; The molding time is 6~48 h; The molding temperature is 25~120℃; The soaking time is 6-48 hours; The soaking temperature is 25~80℃.

10. The application of the multi-block carbazole polyaromatic piperidine polymer according to any one of claims 1 to 6 or the multi-block carbazole polyaromatic piperidine anion exchange membrane according to any one of claims 8 to 9 in the field of hydrogen production by water electrolysis.

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