Pentafluorophenyl aromatic polymer with mercapto-containing azacycle side chain, its preparation method and application, and preparation method of high-temperature proton exchange membrane

Abstract

The present invention relates to the technical field of fuel cell, in particular to a pentafluorophenyl aromatic polymer with a mercapto-containing azacycle in the side chain, its preparation method and application, and a preparation method of a high-temperature proton exchange membrane. The present invention provides a pentafluorophenyl aromatic polymer with a mercapto-containing azacycle in the side chain. The pentafluorophenyl aromatic polymer with a mercapto-containing azacycle in the side chain of the present invention synergistically improves the antioxidant stability of the matrix polymer from three aspects: introducing a highly stable polyaryl main chain skeleton, a carbon-fluorine bond with high bond energy, and a -S- bond with a free radical quenching effect, effectively solving the problem of poor durability of traditional high-temperature proton exchange membrane fuel cells.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and particularly to a pentafluorophenyl aromatic polymer with a mercapto-containing azacycle in the side chain, a preparation method and application thereof, and a preparation method of a high-temperature proton exchange membrane. Background Art

[0002] A proton exchange membrane fuel cell (PEMFC) is a chemical device that directly converts chemical energy into electrical energy. It is not restricted by the Carnot cycle effect, and thus has prominent advantages such as high energy conversion efficiency, fast startup speed, simple structure, and convenient operation and maintenance. It has been widely used as a backup power source, a stationary power station, a power drive system, etc. in the fields of communication, transportation, military, and aerospace. From the perspectives of both sustainable development and environmental protection, PEMFC is currently the most promising power generation technology. Driven by the huge application demand in the field of new energy vehicles in recent years, PEMFC technology has made great progress and development. However, restricted by the characteristics of the perfluorosulfonic acid proton exchange membrane represented by Nafion, the operating temperature of traditional PEMFC is limited to below 80°C, which enables it to use only high-purity hydrogen as fuel and has poor tolerance to impurity gases such as CO. To ensure the power of the battery, measures such as humidification and pressurization need to be taken and a complex water and heat management system needs to be equipped, resulting in the PEMFC system becoming complex and large, and the safety and stability of the system will also be reduced. Increasing the operating temperature of PEMFC is one of the important ways to solve the above problems. A high-temperature proton exchange membrane fuel cell (HT-PEMFC) that can operate at a higher temperature (120 - 200°C) has advantages such as high electrode reaction activity, strong tolerance to impurity gases, and a simple water and heat management system, and has become an important direction in the development and practical application process of EMFC technology.

[0003] As the core component of HT-PEMFC, the performance of the high-temperature proton exchange membrane directly affects the output performance and service life of the fuel cell. Currently, some phosphoric acid-doped alkaline polymer membranes are mainly used as high-temperature proton exchange membranes, and the most representative one is the phosphoric acid-doped polybenzimidazole membrane (PA / PPBI). Currently, companies such as Danish Power Systems and BASF in Germany have developed high-temperature proton exchange membrane electrode assemblies based on PA / PBI membranes and can exhibit good battery performance at 140 - 180°C. However, there are still many problems that cannot be ignored in the production and use of this type of high-temperature proton exchange membrane. PBI has poor solubility in some polar organic solvents, especially when the molecular weight is too high, it is more difficult to dissolve, resulting in a very complex preparation and purification process for PBI. In recent years, the developed alkaline polyarylether copper / sulfone phosphoric acid-doped high-temperature proton exchange membrane has the advantages of simple preparation process, low cost, and easy design of molecular structure, which has attracted the attention of researchers at home and abroad. However, the durability of this type of membrane is poor during the actual operation process of high-temperature fuel cells. Summary of the Invention

[0004] The object of the present invention is to provide a pentafluorophenyl aromatic polymer with a mercapto azacycle-containing side chain, a preparation method and an application thereof, and a preparation method of a high-temperature proton exchange membrane. The pentafluorophenyl aromatic polymer with a mercapto azacycle-containing side chain can effectively solve the problem of poor durability of traditional high-temperature proton exchange membrane fuel cells.

[0005] In order to achieve the above-mentioned invention object, the present invention provides the following technical solutions:

[0006] The present invention provides a pentafluorophenyl aromatic polymer with a mercapto azacycle-containing side chain, having the structure shown in Formula 1:

[0007]

[0008] Wherein, A 1 is

[0009] A 2 is

[0010] R 1 is -H, -CF 3 or -CH 3 ;

[0011] R 2 is

[0012] The present invention also provides a preparation method of the pentafluorophenyl aromatic polymer with a mercapto azacycle-containing side chain as described in the above technical solution, including the following steps:

[0013] Mix an aromatic monomer, a pentafluorophenyl monomer, a catalyst and a first organic solvent, and carry out a polymerization reaction to obtain a pentafluorophenyl aromatic polymer;

[0014] Mix the pentafluorophenyl aromatic polymer, a mercapto azacycle compound, a salt-forming agent and a second organic solvent, and carry out a grafting reaction to obtain the pentafluorophenyl aromatic polymer with a mercapto azacycle-containing side chain;

[0015] The aromatic monomer is biphenyl, p-terphenyl, m-terphenyl or fluorene ring, and the pentafluorophenyl monomer is PhF 5 -R', wherein, R' is -CHO, -COCH 3 or -COCF 3 ;

[0016] The mercapto azacyclic compound is methimazole, methyltriazole, methylbenzimidazole, dimethylmercaptoimidazolium bromide, methylbutylmercaptoimidazolium bromide, methyldecylmercaptoimidazolium bromide, dimethyltriazolium bromide, methylbutyltriazolium bromide, methyldecyltriazolium bromide, dimethylbenzimidazolium bromide, methylbutylbenzimidazolium bromide, methyldecylbenzimidazolium bromide, 1-methimazolium-6-(trimethylammonium)hexyl bromide, 1-methimazolium-6-(methylimidazolium)hexyl bromide, 1-methyltriazolium-6-(trimethylammonium)hexyl bromide, 1-methyltriazolium-6-(methyltriazolium)hexyl bromide, 1-methylbenzimidazolium-6-(trimethylammonium)hexyl bromide, 1-methylbenzimidazolium-6-(methylbenzimidazolium)hexyl bromide.

[0017] Preferably, the catalyst is trifluoromethanesulfonic acid;

[0018] The first organic solvent is dichloromethane.

[0019] Preferably, the molar ratio of the aromatic monomer, pentafluorophenyl monomer and catalyst is 1:1.1:10.

[0020] Preferably, the concentration of the aromatic monomer in the reaction system of the polymerization reaction is 0.38 mol / L.

[0021] Preferably, the molar ratio of the pentafluorophenyl aromatic polymer, mercapto azacyclic compound and salt-forming agent is 1:1.5:1.5;

[0022] The molar ratio of the amount of substance of the pentafluorophenyl aromatic polymer to the volume of the second organic solvent is 1 mol:14 mL.

[0023] Preferably, the salt-forming agent includes anhydrous potassium carbonate and / or anhydrous sodium hydride;

[0024] The second organic solvent is dimethylformamide and / or N-methylpyrrolidone.

[0025] The present invention also provides the application of the pentafluorophenyl aromatic polymer with a mercapto azacyclic group in the side chain as described in the above technical solution or the pentafluorophenyl aromatic polymer with a mercapto azacyclic group in the side chain prepared by the preparation method as described in the above technical solution in a proton exchange membrane.

[0026] The present invention also provides a preparation method of a high-temperature proton exchange membrane, comprising the following steps:

[0027] Mix a pentafluorophenyl aromatic polymer with a mercaptoazacyclic side chain and an organic solvent to obtain a slurry; the pentafluorophenyl aromatic polymer with a mercaptoazacyclic side chain is the pentafluorophenyl aromatic polymer with a mercaptoazacyclic side chain described in the above technical solution or the pentafluorophenyl aromatic polymer with a mercaptoazacyclic side chain prepared by the preparation method described in the above technical solution;

[0028] Cast the slurry into a film and then demold it successively to obtain an intermediate film;

[0029] Soak the intermediate film in a phosphoric acid solution to obtain the high-temperature proton exchange membrane.

[0030] Preferably, the mass concentration of the phosphoric acid solution is 85%;

[0031] The temperature of the soaking is 120 °C and the time is 48 h.

[0032] The present invention provides a pentafluorophenyl aromatic polymer with a mercaptoazacyclic side chain. The pentafluorophenyl aromatic polymer with a mercaptoazacyclic side chain in the present invention synergistically improves the antioxidant stability of the matrix polymer from three aspects: introducing a highly stable polyaryl main chain skeleton, carbon-fluorine bonds with high bond energy, and -S- bonds with a radical quenching effect, effectively solving the problem of poor durability of traditional high-temperature proton exchange membrane fuel cells. Specifically: the aromatic rigid group in the main chain is an oxidation-resistant and stable skeleton; the introduction of pentafluorophenyl can increase the glass transition temperature of the polymer, thereby expanding the temperature range of polymer use; introducing a mercapto group (-S-) in the side chain, the mercapto group can react with free radicals as a radical quencher, thereby inhibiting the attack of free radicals on the polymer skeleton and basic groups, achieving the purpose of enhancing the antioxidant ability of the high-temperature proton exchange membrane. Description of the Drawings

[0033] Figure 1 1H NMR and 19F NMR spectra of the intermediate film (TABPP) in Example 1;

[0034] Figure 2 1H NMR and 19F NMR spectra of the intermediate film (TABPP) in Example 2;

[0035] Figure 3 Stress-strain curves of TABPP in Example 1 and TAPTP in Example 2;

[0036] Figure 4 Stress-strain curves of TABPP / 150% PA in Example 1 and TAPTP / 135% PA in Example 2. Detailed Embodiments

[0037] The present invention provides a pentafluorophenyl aromatic polymer with a mercaptoazacyclic side chain, having the structure shown in Formula 1:

[0038]

[0039] Among them, A 1 is

[0040] A 2 is

[0041] R 1 is -H, -CF 3 or -CH 3 ;

[0042] R 2 is

[0043] The present invention also provides a method for preparing the pentafluorophenyl aromatic polymer with a mercapto azacycle in the side chain as described in the above technical solution, comprising the following steps:

[0044] Mix an aromatic monomer, a pentafluorophenyl monomer, a catalyst and a first organic solvent, and carry out a polymerization reaction to obtain a pentafluorophenyl aromatic polymer;

[0045] Mix the pentafluorophenyl aromatic polymer, a mercapto azacycle compound, a salifying agent and a second organic solvent, and carry out a grafting reaction to obtain the pentafluorophenyl aromatic polymer with a mercapto azacycle in the side chain;

[0046] The aromatic monomer is biphenyl, p-terphenyl, m-terphenyl or fluorene ring, and the pentafluorophenyl monomer is PhF 5 -R', where R' is -CHO, -COCH 3 or -COCF 3 ;

[0047] The mercapto azacycle compound is methyl mercaptoimidazole, methyl mercaptotriazole, methyl mercaptobenzimidazole, dimethyl mercaptoimidazolium bromide, methylbutyl mercaptoimidazolium bromide, methyldecyl mercaptoimidazolium bromide, dimethyl mercaptotriazolium bromide, methylbutyl mercaptotriazolium bromide, methyldecyl mercaptotriazolium bromide, dimethyl mercaptobenzimidazolium bromide, methylbutyl mercaptobenzimidazolium bromide, methyldecyl mercaptobenzimidazolium bromide, 1-methyl mercaptoimidazolium-6-(trimethylammonium) hexyl bromide, 1-methyl mercaptoimidazolium-6-(methylimidazolium) hexyl bromide, 1-methyl mercaptotriazolium-6-(trimethylammonium) hexyl bromide, 1-methyl mercaptotriazolium-6-(methyltriazolium) hexyl bromide, 1-methyl mercaptobenzimidazolium-6-(trimethylammonium) hexyl bromide, 1-methyl mercaptobenzimidazolium-6-(methylbenzimidazolium) hexyl bromide.

[0048] In the present invention, unless otherwise specified, all starting materials for preparation are commercially available products well-known to those skilled in the art.

[0049] In the present invention, an aromatic monomer, a pentafluorophenyl monomer, a catalyst, and a first organic solvent are mixed and subjected to a polymerization reaction to obtain a pentafluorophenyl aromatic polymer.

[0050] In the present invention, the catalyst is preferably trifluoromethanesulfonic acid (TFSA).

[0051] In the present invention, the first organic solvent is preferably dichloromethane (DCM).

[0052] In the present invention, the molar ratio of the aromatic monomer, the pentafluorophenyl monomer, and the catalyst is preferably 1:1.1:10.

[0053] In the present invention, the concentration of the aromatic monomer in the reaction system of the polymerization reaction is preferably 0.38 mol / L.

[0054] In the present invention, the mixing preferably includes first mixing the aromatic monomer and the first organic solvent, then adding the pentafluorophenyl monomer, cooling in an ice bath, and then adding the catalyst. In the present invention, the first mixing is preferably carried out under stirring, and the present invention has no special limitation on the stirring process, and a process well-known to those skilled in the art can be used. The present invention has no special limitation on the addition method of the pentafluorophenyl monomer, and a method well-known to those skilled in the art can be used. In the present invention, the addition method of the catalyst is preferably dropwise addition, and the dropwise addition is preferably carried out using a constant pressure dropping funnel; the present invention has no special limitation on the dropwise addition process, and a process well-known to those skilled in the art can be used.

[0055] In the present invention, the polymerization reaction is preferably carried out under ice bath and stirring conditions, and the present invention has no special limitation on the stirring process, and a process well-known to those skilled in the art can be used. In the present invention, the time of the polymerization reaction is preferably 3 h.

[0056] In the present invention, whether the polymerization reaction is completed is preferably determined by observing the viscosity change of the reaction system. After the viscosity of the system increases sharply, the reaction is stopped. The present invention has no quantitative limitation on the degree of "sharp increase", and it can be judged according to the degree of "sharp increase" conventionally understood in the art.

[0057] After the polymerization reaction is completed, the present invention preferably allows the product obtained from the polymerization reaction to stand in absolute ethanol for 10 h and then discharges it to obtain a white solid; the white solid is successively pulverized, washed, and dried. In the present invention, the pulverization is preferably carried out using a pulverizer. In the present invention, the washing is preferably heating under reflux in ethanol 8 times; the purpose of the washing is to remove excessive monomer compounds and solvents. The present invention has no special limitation on the drying process, and a process well-known to those skilled in the art can be used. In the present invention, the drying is preferably carried out in an oven.

[0058] After obtaining the pentafluorophenyl aromatic polymer, the present invention mixes the pentafluorophenyl aromatic polymer, the mercapto azacyclic compound, the salt-forming agent, and the second organic solvent, and carries out a grafting reaction to obtain the pentafluorophenyl aromatic polymer with a mercapto azacyclic group in the side chain.

[0059] In the present invention, the salt-forming agent preferably includes potassium carbonate anhydrous and / or sodium hydride anhydrous. When the salt-forming agent is potassium carbonate anhydrous and sodium hydride anhydrous, the present invention has no special limitation on the ratio of potassium carbonate anhydrous and sodium hydride anhydrous, and they can be mixed in any ratio.

[0060] In the present invention, the second organic solvent is preferably dimethylformamide (DMF) and / or N-methylpyrrolidone (NMP); when the second organic solvent is dimethylformamide and N-methylpyrrolidone, the present invention has no special limitation on the ratio of dimethylformamide and N-methylpyrrolidone, and they can be mixed in any ratio.

[0061] In the present invention, the molar ratio of the pentafluorophenyl aromatic polymer, the mercapto azacyclic compound, and the salt-forming agent is preferably 1:1.5:1.5.

[0062] In the present invention, the molar ratio of the amount of substance of the pentafluorophenyl aromatic polymer to the volume of the second organic solvent is preferably 1 mol:14 mL.

[0063] In the present invention, the processes of the mixing and the grafting reaction preferably include the following steps:

[0064] Mix the mercapto azacyclic compound, the salt-forming agent, and a part of the second organic solvent, and carry out a first reaction to obtain a first reaction system;

[0065] Mix the pentafluorophenyl aromatic polymer and the remaining organic solvent to obtain a pentafluorophenyl aromatic polymer solution;

[0066] Mix the pentafluorophenyl aromatic polymer solution with the first reaction system, and carry out a second reaction.

[0067] The present invention mixes a mercapto azacyclic compound, a salt-forming agent, and a partial second organic solvent to carry out a first reaction to obtain a first reaction system.

[0068] In the present invention, the molar ratio of the pentafluorophenyl aromatic polymer to the volume of the partial second organic solvent is preferably 1 mol: 5 mL.

[0069] In the present invention, the mixing is preferably carried out under stirring conditions. The present invention has no special limitations on the stirring process, and it can be carried out by using a process well-known to those skilled in the art.

[0070] In the present invention, the first reaction is preferably carried out in a protective atmosphere, and the protective atmosphere is preferably a nitrogen atmosphere; the temperature of the first reaction is preferably 80 °C, and the time is preferably 3 h.

[0071] In the present invention, the reaction type of the first reaction is preferably superacid catalysis.

[0072] The present invention mixes a pentafluorophenyl aromatic polymer and the remaining organic solvent to obtain a pentafluorophenyl aromatic polymer solution.

[0073] The present invention has no special limitations on the mixing process, and a process well-known to those skilled in the art can be used to dissolve the pentafluorophenyl aromatic polymer in the remaining organic solvent.

[0074] After obtaining the first reaction system and the pentafluorophenyl aromatic polymer solution, the present invention mixes the pentafluorophenyl aromatic polymer solution with the first reaction system to carry out a second reaction.

[0075] In the present invention, the mixing is preferably to dropwise add the pentafluorophenyl aromatic polymer solution into the first reaction system; the present invention has no special limitations on the dropping process, and it can be carried out by using a process well-known to those skilled in the art. In the examples of the present invention, the dropping is carried out using a constant pressure dropping funnel.

[0076] In the present invention, the second reaction is preferably carried out in a protective atmosphere, and the protective atmosphere is preferably a nitrogen atmosphere; the temperature of the second reaction is preferably 80 °C, and the time is preferably 6 h.

[0077] In the present invention, the reaction type of the second reaction is preferably nucleophilic substitution.

[0078] After the grafting reaction is completed, the present invention preferably further includes allowing the product obtained from the grafting reaction to stand in anhydrous diethyl ether for 10 h and then discharging to obtain a yellow solid; successively pulverizing, washing, and drying the yellow solid; the pulverization is preferably carried out using a pulverizer; the present invention has no special limitation on the pulverization process, and a process well-known to those skilled in the art can be used. In the present invention, the washing is preferably carried out by stirring and washing 8 times in distilled water; the purpose of the washing is to remove excess salt-forming agent and nitrogen heterocyclic compounds. In the present invention, the drying is preferably carried out in an oven; the present invention has no special limitation on the drying conditions, and a process well-known to those skilled in the art can be used.

[0079] The present invention also provides the application of the pentafluorophenyl aromatic polymer with a mercapto nitrogen heterocycle in the side chain as described in the above technical solution or the pentafluorophenyl aromatic polymer with a mercapto nitrogen heterocycle in the side chain prepared by the preparation method as described in the above technical solution in a proton exchange membrane.

[0080] The present invention also provides a preparation method of a high-temperature proton exchange membrane, comprising the following steps:

[0081] Mixing the pentafluorophenyl aromatic polymer with a mercapto nitrogen heterocycle in the side chain and a third organic solvent to obtain a slurry; the pentafluorophenyl aromatic polymer with a mercapto nitrogen heterocycle in the side chain is the pentafluorophenyl aromatic polymer with a mercapto nitrogen heterocycle in the side chain as described in the above technical solution or the pentafluorophenyl aromatic polymer with a mercapto nitrogen heterocycle in the side chain prepared by the preparation method as described in the above technical solution;

[0082] Successively casting the slurry into a film and demolding to obtain an intermediate film;

[0083] Soaking the intermediate film in a phosphoric acid solution to obtain the high-temperature proton exchange membrane.

[0084] The present invention mixes the pentafluorophenyl aromatic polymer with a mercapto nitrogen heterocycle in the side chain and a third organic solvent to obtain a slurry.

[0085] In the present invention, the third organic solvent is preferably N-methylpyrrolidone (NMP).

[0086] The present invention has no special limitation on the mixing process, and a process well-known to those skilled in the art can be used.

[0087] In the present invention, the concentration of the slurry is preferably 0.05 g / mL.

[0088] After obtaining the slurry, the present invention successively casts the slurry into a film and demolds to obtain an intermediate film.

[0089] Before casting into a film, the present invention preferably filters the slurry, and the filter cloth used for the filtration is a 400-mesh filter cloth. In the present invention, the process of casting into a film is preferably to cast and spread the slurry on a glass plate and then cure it. In the present invention, the temperature of the curing is preferably 70 °C, and the time is preferably 12 h. The present invention does not have any special limitation on the process of demolding, and the process well-known to those skilled in the art can be adopted. In the embodiment of the present invention, the demolding is preferably natural demolding in water. After the demolding is completed, the present invention preferably further includes drying. The present invention does not have any special limitation on the process of drying, and the film can be placed in an oven to dry the excess moisture by using the process well-known to those skilled in the art.

[0090] After obtaining the intermediate film, the present invention soaks the intermediate film in a phosphoric acid solution to obtain the high-temperature proton exchange membrane.

[0091] In the present invention, the mass concentration of the phosphoric acid solution is preferably 85%; the temperature of the soaking is preferably 120 °C, and the time is preferably 48 h.

[0092] In the present invention, the purpose of carrying out phosphoric acid doping is to serve as a proton carrier for the high-temperature membrane.

[0093] The following describes in detail the chain-containing mercapto azacycle pentafluorophenyl aromatic polymer provided by the present invention, its preparation method and application, and the preparation method of the high-temperature proton exchange membrane in conjunction with the embodiments, but they cannot be understood as limiting the protection scope of the present invention.

[0094] Example 1

[0095]

[0096] After adding 12 mmol of biphenyl and dichloromethane into a three-necked flask equipped with a mechanical stirring device and stirring to dissolve (the concentration of biphenyl in the obtained mixed solution is 0.38 mol / L), 13.2 mmol of pentafluorobenzaldehyde is added, the temperature is lowered in an ice bath, 120 mmol of catalyst TFSA is dropped into the mixture through a constant-pressure dropping funnel, and the mixture is continuously stirred for 3 h. After observing that the viscosity of the system increases sharply, the reaction is stopped. The product obtained from the polymerization reaction is allowed to stand in absolute ethanol for 10 h and then discharged to obtain a white solid; after the white solid is crushed by a crusher, it is heated under reflux in ethanol and washed 8 times to remove the excessive monomers and solvents, and then dried in an oven to obtain the pentafluorophenyl aromatic polymer;

[0097] 4.5 mmol of 3-mercapto-4-methyl-4H-1,2,4-triazole, 4.5 mmol of anhydrous potassium carbonate and 15 mL of N,N-dimethylformamide were added to a three-necked flask equipped with a thermometer, a spherical condenser and a mechanical stirring device, and reacted at 80 °C for 3 h under nitrogen protection to obtain a first product system; 3 mmol of pentafluorophenyl aromatic polymer and 27 mL of N,N-dimethylformamide were mixed to obtain a pentafluorophenyl aromatic polymer solution; through a constant pressure dropping funnel, the pentafluorophenyl aromatic polymer solution was dropped into the first product system, and the reaction was continued at 80 °C for 6 h under nitrogen protection. After that, the product obtained from the grafting reaction was allowed to stand in anhydrous ether for 10 h and then discharged to obtain a yellow solid; the yellow solid was pulverized by a pulverizer and stirred and washed 8 times in distilled water to remove excess anhydrous potassium carbonate and 3-mercapto-4-methyl-4H-1,2,4-triazole, and finally dried in an oven to obtain a pentafluorophenyl aromatic polymer with a mercapto-containing azacycle in the side chain;

[0098] 0.5 g of pentafluorophenyl aromatic polymer with a mercapto-containing azacycle in the side chain and 10 mL of N-methylpyrrolidone were mixed and stirred until completely dissolved to obtain a slurry; the slurry was filtered through a 400-mesh filter cloth, then cast and spread on a glass plate, dried and cured at 70 °C in a constant temperature oven for 12 h and then taken out, naturally demoulded in water, and the excess water was dried in an oven to obtain an intermediate membrane (denoted as TABPP); the intermediate membrane was soaked in 85% by mass concentration of phosphoric acid at 120 °C for 48 h to obtain a high-temperature proton exchange membrane (denoted as TABPP / 150% PA, the phosphoric acid doping amount in the high-temperature proton exchange membrane was 150%; the volume swelling degree after doping with phosphoric acid was 65%, the tensile strength of the intermediate membrane was 58.96 MPa, the tensile strength of the high-temperature proton exchange membrane was 11.49 MPa, and the proton conductivity at 200 °C was 103 mS / cm);

[0099] Figure 1 1H NMR and 19F NMR spectra of the intermediate membrane (denoted as TABPP), from Figure 1 it can be seen that TABPP was successfully synthesized.

[0100] Example 2

[0101]

[0102] 12 mmol of p-terphenyl and dichloromethane were added to a three-necked flask equipped with a mechanical stirring device and stirred until dissolved (the concentration of terphenyl in the resulting mixture was 0.38 mol / L). Then, 13.2 mmol of pentafluorobenzaldehyde was added. The temperature was lowered using an ice bath, and 120 mmol of the catalyst TFSA was added dropwise through a constant-pressure dropping funnel while continuously stirring for 3 h. When it was observed that the viscosity of the system increased significantly, the reaction was stopped. The product obtained from the polymerization reaction was allowed to stand in absolute ethanol for 10 h and then discharged to obtain a white solid. The white solid was pulverized using a pulverizer and then heated under reflux in ethanol and washed 8 times to remove excess monomers and solvents. It was dried in an oven to obtain a pentafluorophenyl aromatic polymer (the structural formula of the pentafluorophenyl aromatic polymer is);

[0103] 4.5 mmol of 3-mercapto-4-methyl-4H-1,2,4-triazole, 4.5 mmol of anhydrous potassium carbonate, and 42 mL of N-methylpyrrolidone were added to a three-necked flask equipped with a thermometer, a spherical condenser, and a mechanical stirring device. The reaction was carried out at 80 °C for 3 h under nitrogen protection to obtain a first product system. 3 mmol of the pentafluorophenyl aromatic polymer and 27 mL of N,N-dimethylformamide were mixed to obtain a pentafluorophenyl aromatic polymer solution. Through a constant-pressure dropping funnel, the pentafluorophenyl aromatic polymer solution was added dropwise into the first product system. The reaction was continued at 80 °C for 6 h under nitrogen protection. The product obtained from the grafting reaction was allowed to stand in anhydrous ether for 10 h and then discharged to obtain a yellow solid. The yellow solid was pulverized using a pulverizer and then stirred and washed 8 times in distilled water to remove excess anhydrous potassium carbonate and 3-mercapto-4-methyl-4H-1,2,4-triazole. Finally, it was dried in an oven to obtain a pentafluorophenyl aromatic polymer with a mercapto-containing azole ring in the side chain;

[0104] 0.5 g of the pentafluorophenyl aromatic polymer with a mercapto-containing azole ring in the side chain and 10 mL of N-methylpyrrolidone were mixed and stirred until completely dissolved to obtain a slurry. The slurry was filtered through a 400-mesh filter cloth, then cast and spread on a glass plate, dried and cured in an incubator at 70 °C for 12 h, taken out, naturally demolded in water, and dried in an oven to remove excess moisture to obtain an intermediate membrane (denoted as TAPTP). The intermediate membrane was soaked in phosphoric acid with a mass concentration of 85% at 120 °C for 48 h to obtain a high-temperature proton exchange membrane (denoted as TAPTP / 135% PA, the phosphoric acid doping amount in the high-temperature proton exchange membrane was 135%; the volume swelling degree after doping with phosphoric acid was 45%, the tensile strength of the intermediate membrane was 66.68 MPa, and the tensile strength of the high-temperature proton exchange membrane was 16.05 MPa, and the proton conductivity at 200 °C was 67.8 mS / cm);

[0105] Figure 2 are the proton nuclear magnetic resonance spectrum and fluorine nuclear magnetic resonance spectrum of the intermediate membrane (denoted as TAPTP), from Figure 2It can be seen that TAPTP was successfully synthesized;

[0106] Figure 3 are the stress-strain curves of TABPP described in Example 1 and TAPTP described in Example 2, Figure 4 are the stress-strain curves of TABPP / 150% PA described in Example 1 and TAPTP / 135% PA described in Example 2; It can be seen from Figure 3 and Figure 4 that the tensile strength of the high-temperature proton-reducing membrane after phosphoric acid doping is greater than 10 MPa.

[0107] Example 3

[0108]

[0109] 12 mmol of p-terphenyl and dichloromethane were added to a three-necked flask equipped with a mechanical stirring device and stirred until dissolved (the concentration of terphenyl in the resulting mixed solution was 0.38 mol / L), then 13.2 mmol of perfluorobenzophenone was added, and the temperature was lowered in an ice bath. 120 mmol of the catalyst TFSA was dropped in through a constant-pressure dropping funnel, and stirring was continued for 3 h. When it was observed that the viscosity of the system increased sharply, the reaction was stopped. The product obtained from the polymerization reaction was allowed to stand in absolute ethanol for 10 h and then discharged to obtain a white solid; the white solid was pulverized by a pulverizer and then heated under reflux in ethanol and washed 8 times to remove excess monomers and solvents, and dried in an oven to obtain a pentafluorophenyl aromatic polymer;

[0110] 4.5 mmol of 3-mercapto-4-methyl-4H-1,2,4-triazole, 4.5 mmol of anhydrous potassium carbonate and 42 mL of N-methylpyrrolidone were added to a three-necked flask equipped with a thermometer, a spherical condenser and a mechanical stirring device, and reacted at 80 °C for 3 h under nitrogen protection to obtain a first product system; 3 mmol of the pentafluorophenyl aromatic polymer and 27 mL of N,N-dimethylformamide were mixed to obtain a pentafluorophenyl aromatic polymer solution; through a constant-pressure dropping funnel, the pentafluorophenyl aromatic polymer solution was dropped into the first product system, and the reaction was continued at 80 °C for 6 h under nitrogen protection. Then, the product obtained from the grafting reaction was allowed to stand in anhydrous ether for 10 h and then discharged to obtain a yellow solid; the yellow solid was pulverized by a pulverizer and then stirred and washed 8 times in distilled water to remove excess anhydrous potassium carbonate and 3-mercapto-4-methyl-4H-1,2,4-triazole, and finally dried in an oven to obtain a pentafluorophenyl aromatic polymer with a mercapto-containing azole heterocycle in the side chain;

[0111] 0.5 g of pentafluorophenyl aromatic polymer with a mercapto-containing azacycle side chain was mixed with 10 mL of N-methylpyrrolidone and stirred until completely dissolved to obtain a slurry; the slurry was filtered through a 400-mesh filter cloth, then cast and spread on a glass plate, taken out after drying and curing at 70 °C in an incubator for 12 h, naturally demembraned in water, and the excess water was dried in an oven to obtain an intermediate film; the intermediate film was soaked in phosphoric acid with a mass concentration of 85% at 120 °C for 48 h to obtain a high-temperature proton exchange membrane (the phosphoric acid doping amount in the high-temperature proton exchange membrane was 95%; the volume swelling degree after doping with phosphoric acid was 40%, the tensile strength of the intermediate film was 64.70 MPa, the tensile strength of the high-temperature proton exchange membrane was 19.80 MPa, and the proton conductivity at 200 °C was 37 mS / cm).

[0112] Test Example 1

[0113] The TABPP (Group A) described in Example 1, the TABPP / 150% PA (Group B) described in Example 1, the TAPTP (Group C) described in Example 3, and the TAPTP / 135% PA (Group D) described in Example 2 were respectively made into rectangular splines of 4 mm × 3 cm, weighed and their masses were recorded, and then immersed in Fenton's reagent at 80 °C (3% H 2 O 2 , 4 ppm Fe 2+ ), and the sample tube was gently shaken every 15 min until the spline cracked, and this period of time was recorded as the breaking time of the spline, as shown in Table 1:

[0114] Table 1 Breaking times of TABPP, TABPP / 150% PA, TAPTP, and TAPTP / 135% PA

[0115] sample A B C D breaking time 133h 33h 115h 45h

[0116] As can be seen from Table 1, the high-temperature proton exchange membrane prepared by the present invention has high antioxidant stability.

[0117] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. Application of a pentafluorophenyl aromatic polymer with a mercapto azacycle in the side chain in a proton exchange membrane, Characterized in that, The pentafluorophenyl aromatic polymer with a mercapto azacycle in the side chain has the structure shown in Formula 1: In Formula 1, A 1 is A 2 For R 1 is -H, -CF 3 or -CH 3 ; R 2 For The preparation method of the pentafluorophenyl aromatic polymer with a mercapto azacycle in the side chain comprises the following steps: Mix an aromatic monomer, a pentafluorophenyl monomer, a catalyst and a first organic solvent, and carry out a polymerization reaction to obtain a pentafluorophenyl aromatic polymer; Mix the pentafluorophenyl aromatic polymer, a mercapto azacycle compound, a salt-forming agent and a second organic solvent, and carry out a grafting reaction to obtain the pentafluorophenyl aromatic polymer with a mercapto azacycle in the side chain; The aromatic monomer is biphenyl, p-terphenyl, m-terphenyl or fluorene ring, and the pentafluorophenyl monomer is PhF 5 -R', where R' is -CHO, -COCH 3 or -COCF 3 ; The mercapto azacycle compound is methyl mercaptoimidazole, methyl mercaptotriazole, methyl mercaptobenzimidazole, dimethyl mercaptoimidazolium bromide, methylbutyl mercaptoimidazolium bromide, methyldecyl mercaptoimidazolium bromide, dimethyl mercaptotriazolium bromide, methylbutyl mercaptotriazolium bromide, methyldecyl mercaptotriazolium bromide, dimethyl mercaptobenzimidazolium bromide, methylbutyl mercaptobenzimidazolium bromide, methyldecyl mercaptobenzimidazolium bromide, 1-methyl mercaptoimidazolium-6-(trimethylammonium)hexyl bromide, 1-methyl mercaptoimidazolium-6-(methylimidazolium)hexyl bromide, 1-methyl mercaptotriazolium-6-(trimethylammonium)hexyl bromide, 1-methyl mercaptotriazolium-6-(methyltriazolium)hexyl bromide, 1-methyl mercaptobenzimidazolium-6-(trimethylammonium)hexyl bromide, 1-methyl mercaptobenzimidazolium-6-(methylbenzimidazolium)hexyl bromide.

2. The application according to claim 1, Characterized in that, The catalyst is trifluoromethanesulfonic acid; The first organic solvent is dichloromethane.

3. The application according to claim 1 or 2, Characterized in that, The molar ratio of the aromatic monomer, the pentafluorophenyl monomer and the catalyst is 1:1.1:

10.

4. The application according to claim 3, Characterized in that, The concentration of the aromatic monomer in the reaction system of the polymerization reaction is 0.38 mol / L.

5. The application according to claim 1, Characterized in that, The molar ratio of the pentafluorophenyl aromatic polymer, the mercapto azacycle compound and the salt-forming agent is 1:1.5:1.5; The molar ratio of the amount of substance of the pentafluorophenyl aromatic polymer to the volume of the second organic solvent is 1 mol:14 mL.

6. The application according to claim 5, Characterized in that, The salt-forming agent includes anhydrous potassium carbonate and / or anhydrous sodium hydride; The second organic solvent is dimethylformamide and / or N-methylpyrrolidone.

7. A preparation method of a high-temperature proton exchange membrane, Characterized in that, Comprises the following steps: Mix the pentafluorophenyl aromatic polymer with a mercapto azacycle in the side chain and a third organic solvent to obtain a slurry; the pentafluorophenyl aromatic polymer with a mercapto azacycle in the side chain is the pentafluorophenyl aromatic polymer with a mercapto azacycle in the side chain as described in claim 1; Cast the slurry into a film and then demold it successively to obtain an intermediate film; Soak the intermediate film in a phosphoric acid solution to obtain the high-temperature proton exchange membrane.

8. The preparation method according to claim 7, Characterized in that, The mass concentration of the phosphoric acid solution is 85%; The temperature of the soaking is 120 °C and the time is 48 h.

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