Composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane and preparation method thereof

Abstract

The invention relates to the field of polymer functional membrane materials, and particularly provides a composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane and a preparation method thereof. Sulfonated poly (arylene ether nitrile sulfone) is synthesized through nucleophilic substitution reaction, and the sulfonated poly (arylene ether nitrile sulfone) and sulfonated cobalt phthalocyanine are subjected to blending and casting to form a membrane, so that the provided composite sulfonated poly (arylene ether nitrile sulfone) proton exchange resin contains a sulfonic acid structural unit, a sulfone structural unit, a polar cyano group and a phthalocyanine structural unit; the problem that an existing proton exchange membrane is low in sulfonation degree and proton conductivity can be solved, and the proton exchange membrane has the advantages of being high in structural stability, good in mechanical property, excellent in thermal stability and high in safety. The introduction of sulfonated cobalt phthalocyanine can effectively improve the internal structure of the sulfonated polyarylene ether nitrile sulfone proton exchange membrane, promote the conduction rate of water molecules in the membrane, and further improve the proton conductivity of the sulfonated polyarylene ether nitrile sulfone proton exchange membrane. In addition, the manufacturing process is green and simple, the compounding cost is low, and the application prospect is very wide.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of functional polymer materials, and relates to a polymer functional membrane material, in particular to a composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane and a preparation method thereof. BACKGROUND

[0002] Proton exchange membrane fuel cell (PEMFC) is the fifth generation of fuel cell, which has a rapid development momentum. Due to its low working temperature, high specific power and fast start-up speed, it can be used as a power source for electric vehicles, and is particularly suitable for small mobile power sources and other power equipment, and has a wide application prospect in the fields of automobiles, residential houses, small and medium-sized power stations and portable devices.

[0003] Proton exchange membrane is the most core part in PEMFC, which mainly plays two roles. One is to transfer protons from the anode region to the cathode region as a proton selective membrane, and the other is to avoid the contact of fuel and oxidant as a diaphragm material. The performance of the proton exchange membrane can directly affect the cell efficiency of PEMFC, so the membrane must have excellent comprehensive performance, such as high proton activity and proton conductivity, excellent thermal stability and mechanical properties, acid and alkali resistance, good dimensional stability, high selectivity and moderate cost performance, etc.

[0004] Nowadays, the most widely used proton exchange membrane in commercial use is perfluorosulfonic acid membrane, namely Nafion membrane. This kind of membrane is mainly composed of hydrophilic ion exchange groups (-SO3H) and hydrophobic polytetrafluoroethylene skeleton. The bond energy of C-F bond in the main chain is high, and the radius of F atom is large, so the membrane has good mechanical properties and chemical stability; the sulfonic acid group is a strong hydrophilic group, which can not only absorb water molecules, but also provide protons, and at the same time, due to the strong electrophilicity of fluorine atom, the sulfonic acid group is equivalent to sulfuric acid in acidity, which endows the membrane with excellent proton conductivity, so that the perfluorosulfonic acid membrane becomes the mainstream diaphragm material in PEMFC. However, the fluorination process of perfluorosulfonic acid membrane will pollute the environment, the preparation process is complex, the cost is high, and the methanol blocking effect is poor, which leads to the decrease of cell efficiency, so it is of great significance to develop a fluorine-free proton exchange membrane with high cost performance, simple manufacturing process and high alcohol blocking performance.

[0005] Sulfonated polyarylene ether nitrile (PAHN) membranes, as a type of fluorine-free proton exchange membrane, exhibit high strength, high proton conductivity, and good dimensional stability due to the presence of cyano side groups. Their polar-polar interactions reduce membrane hygroscopicity and improve polymer-electrode adhesion. Furthermore, their molecular design is controllable, facilitating synthesis. However, the properties of PAHN are highly dependent on the degree of sulfonation. Generally, higher sulfonation results in higher conductivity but poorer dimensional stability and higher methanol permeability. Conversely, membranes with lower sulfonation exhibit lower conductivity, making it difficult to simultaneously meet the combined requirements of high conductivity, high selectivity, and excellent mechanical properties. Summary of the Invention

[0006] In view of this, the purpose of this invention is to overcome the disadvantage of the difficulty in balancing the high proton conductivity and high selectivity of sulfonated polyarylene ether nitrile, thereby providing a composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane with high conductivity, high selectivity and excellent mechanical properties, and a method for preparing the same.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A method for preparing a composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane with high conductivity, high selectivity and excellent mechanical properties is specifically carried out according to the following steps: (1) Preparation of sulfonated polyarylene ether nitrile sulfone proton exchange resin Step 1: In a three-necked flask equipped with a reflux condenser, a mechanical stirrer, a thermometer, and a water separator, 17.806 g of 2,6-difluorobenzonitrile, 11.262 g of 4,4'-dihydroxydiphenyl sulfone, and 9.610 g of potassium 2,5-dihydroxybenzenesulfonate were added sequentially as reactants, and 21.227 g of potassium carbonate was added as a catalyst to obtain a mixed powder; the water separator was then filled with toluene solution. In step one, the molar ratio of potassium 2,5-dihydroxybenzenesulfonate and 4,4'-dihydroxydiphenyl sulfone is 6:4, and the total molar mass of 4,4'-dihydroxydiphenyl sulfone and potassium 2,5-dihydroxybenzenesulfonate is in a molar ratio of 1:1 to that of 2,6-difluorobenzonitrile. The amount of potassium carbonate relative to 2,6-difluorobenzonitrile is kept in excess by 20%, that is, the molar ratio of potassium carbonate to 2,6-difluorobenzonitrile is 1.2:1.

[0008] Step 2: Add the powdered mixture obtained in Step 1 to a mixed solvent of 65 mL N-methylpyrrolidone and 21 mL toluene to obtain mixture A; In step two, each gram of the mixture powder is dissolved in (1~1.2) mL of N-methylpyrrolidone solvent; in the mixed solvent, the volume ratio of N-methylpyrrolidone to toluene is 3:1.

[0009] Step 3: Place the mixture A obtained in Step 2 in an oil bath at 5°C.o A heating rate of C / min will raise the temperature to 135~140. o C, and the reaction was continued at this temperature range for 4 h; then at 5 o The temperature continued to rise at a rate of C / min to 165 o The reaction was carried out at a constant temperature of C for 3 hours; during this stage, toluene and water were discharged from the separator at a rate of 5 mL / 30 min. Finally, the mixture was discharged at 5 mL / min. o The heating rate of C / min will raise the temperature to 180. o C. Continue stirring until the viscosity of the mixture no longer changes. Cool the mixture to 150°C. o C. Pour the obtained reaction solution into a 1 mol / L dilute hydrochloric acid / dilute sulfuric acid solution, stir, and obtain solid A; Step 4: Soak the solid A obtained in Step 3 in a 1 mol / L dilute hydrochloric acid / dilute sulfuric acid solution for 24 h, grind it into powder using a pulverizer, soak the powder in an acetone / ethanol solution for 12 h; after washing and filtration, wash with deionized water 3-5 times until the solution is neutral; place the washed powder in a vacuum oven and dry for 48 h, the resulting white powder is the sulfonated polyarylene ether nitrile sulfone matrix resin. (2) The preparation method of the composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane includes the following steps: Step 1: Dissolve a certain amount of sulfonated polyarylene ether nitrile sulfone resin in a mixed solvent of N,N-dimethylacetamide and deionized water, and heat at 160°C. o C, 200 r min -1 The mixture was stirred and refluxed for 3 h to obtain a transparent solution A of sulfonated polyarylene ether nitrile sulfone with a mass concentration of 5-7 mg / mL.

[0010] In step one, the volume ratio of deionized water to the volume of the mixed solvent is 0.1~0.15.

[0011] Step 2: Dissolve sulfonated cobalt phthalocyanine in a certain amount of N,N-dimethylacetamide, and sonicate under 100 W ultrasonic power for 2 h at room temperature to prepare a uniform dispersion B with a solution concentration of 1-4 mg / mL.

[0012] Step 3: Slowly add the uniformly dispersed solution B prepared in Step 2 dropwise to the transparent solution A prepared in Step 1, at 50°C. o C, Ultrasound at 100 W power with assisted 200-300 r / min -1 Mechanical stirring and heating for 4 h were used to prepare a sulfonated cobalt phthalocyanine mixture C uniformly dispersed in a sulfonated polyarylene ether nitrile sulfone matrix.

[0013] The mass fraction of sulfonated cobalt phthalocyanine in mixture C is 5-20 wt%, and 9-13 mL of N,N-dimethylacetamide and 1-2 mL of deionized water are added to each 1 g of sulfonated polyarylene ether nitrile sulfone resin.

[0014] Step 4: Drop the uniformly dispersed mixture C onto a clean and level glass substrate, allowing it to naturally flow and form a film, and place it at a temperature of 80°C. o Heat treatment in oven C for 2 hours at 100°C. o C, 120 o C, 140 o C and 160 o Each membrane is heat-treated at C for 2 hours to remove solvent from the membrane as much as possible.

[0015] Step 5: Allow the temperature to cool naturally to room temperature, remove the glass plate from the oven, and then immerse it in 1 mol L⁻¹ water. -1 The membrane was immersed in a dilute acid solution for 24 hours, allowing it to detach naturally from the glass plate while simultaneously undergoing sufficient proton exchange with the acid. The membrane surface was then repeatedly washed with deionized water and wiped clean with filter paper before being placed at 80°C. o A composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane with a sulfonated cobalt phthalocyanine mass fraction of 5-20 wt% can be obtained by drying in a vacuum oven at C for 24-36 h.

[0016] The acid mentioned in step five can be dilute sulfuric acid or dilute hydrochloric acid; the thickness of the composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane is approximately 40-60 μm.

[0017] It should be noted that the 2,6-difluorobenzonitrile, 4,4'-dihydroxydiphenyl sulfone, potassium 2,5-dihydroxybenzenesulfonate, N-methylpyrrolidone, N,N-dimethylacetamide, toluene, acid, ethanol / acetone, sulfonated cobalt phthalocyanine, and other reagents used above were all of analytical grade. The number-average molecular weight of the sulfonated polyarylene ether nitrile sulfone matrix is ​​2.84 × 10⁻⁶. 4 Da, with a weight-average molecular weight of 3.96 × 10⁻⁶. 4 The polydispersity index (PDI) is 1.39.

[0018] Compared with the prior art, the beneficial effects of the present invention are: (1) The preparation conditions for sulfonated polyarylene ether sulfones are mild and the process is simple and easy to implement; (2) The sulfonated cobalt phthalocyanine introduced in this invention can provide additional proton transport groups for the composite material, improve the proton conductivity of the composite membrane, and enhance the compatibility with the polyarylene ether nitrile sulfone matrix, providing a good platform for proton jumping. This enables the preparation of a composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane with high conductivity, high selectivity, good dimensional stability and excellent mechanical properties. (3) The composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane prepared by the present invention inherits the excellent heat resistance of the sulfonated polyarylene ether nitrile sulfone matrix and solves the problem that the composite proton exchange membrane is difficult to have both high proton conductivity and excellent dimensional stability. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the preparation process of sulfonated polyarylene ether sulfone resin.

[0021] Figure 2 Electron photograph of a composite sulfonated polyarylene ether sulfone proton exchange membrane.

[0022] Figure 3 The mechanical properties of the composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane under both dry and wet conditions are described.

[0023] Figure 4 It represents the proton conductivity of a composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane at different temperatures.

[0024] Figure 5 It is the methanol permeability and selectivity of the composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane at room temperature. Detailed Implementation

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] The term "embodiment" used herein, as an example, is not necessarily to be construed as superior to or better than other embodiments. Performance testing in the embodiments of this application, unless otherwise specified, employs conventional testing methods in the art. It should be understood that the terminology used in this application is merely for describing particular implementations and is not intended to limit the scope of this disclosure.

[0027] Unless otherwise stated, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; other experimental methods and technical means not specifically mentioned herein refer to experimental methods and technical means commonly used by one of ordinary skill in the art.

[0028] In the description of this invention, it should be understood that the terms "middle", "upper", "lower", "rise", "fall", "vertical", "surface", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0029] To better illustrate the content of this application, numerous specific details are provided in the following detailed embodiments. Those skilled in the art should understand that this application can be implemented even without certain specific details. In the embodiments, some methods, means, instruments, and devices well-known to those skilled in the art are not described in detail in order to highlight the main points of this application.

[0030] Without conflict, the technical features disclosed in the embodiments of this application can be combined arbitrarily, and the resulting technical solution belongs to the content disclosed in the embodiments of this application.

[0031] This invention discloses a composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane and its preparation method.

[0032] The composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane provided in this embodiment of the invention is a composite of sulfonated cobalt phthalocyanine as filler and sulfonated polyarylene ether nitrile sulfone matrix; the mass fraction of the filler in the composite material is 5-20 wt%.

[0033] The preparation method of the composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane provided in this invention includes the following steps: (1) Preparation of sulfonated polyarylene ether nitrile sulfone matrix resin: 2,6-Difluorobenzonitrile, 4,4'-dihydroxydiphenyl sulfone, potassium 2,5-dihydroxybenzenesulfonate, and potassium carbonate were mixed and dissolved in a mixed solvent of N-methylpyrrolidone and toluene, and then heated at 135-140 °C. o The reaction was mechanically stirred in a constant-temperature oil bath at C for 4 hours, after which the temperature was raised to 165°C. o C, react for 3 h; finally raise the temperature to 180 o C. Continue stirring until the viscosity of the mixture no longer changes. Reduce the temperature of the mixture to 150°C. oAfter step C, pour the solution into a 1 mol / L dilute hydrochloric acid / dilute sulfuric acid solution, stir, filter, and pulverize. Soak the pulverized powder in acetone / ethanol, wash and filter, wash several times with deionized water, and dry in a vacuum oven to obtain sulfonated polyarylene ether nitrile sulfone matrix resin. (2) Mixing of sulfonated cobalt phthalocyanine and sulfonated polyarylene ether nitrile sulfone matrix resin: Sulfonated polyarylene ether nitrile sulfone is dissolved in a mixed solvent of N,N-dimethylacetamide and deionized water to obtain a transparent solution A of sulfonated polyarylene ether nitrile sulfone; sulfonated cobalt phthalocyanine is dissolved in N,N-dimethylacetamide and mixed thoroughly, and ultrasonic-assisted mechanical stirring is used to obtain a uniform dispersion B; dispersion B is slowly added dropwise to sulfonated polyarylene ether nitrile sulfone transparent solution A, and ultrasonic-assisted mechanical stirring is used to mix it thoroughly, and the mixture is heated under reflux to obtain a mixed solution C.

[0034] (3) Preparation of composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane: The mixture C is dropped onto a clean and horizontal glass substrate and allowed to flow naturally to form a film. It is then heat-treated at different temperature ranges. After the heat treatment, the composite material is allowed to cool naturally, demold, acid-soaked, washed and dried.

[0035] In a preferred embodiment of the present invention, in step (1), the molar ratio of potassium 2,5-dihydroxybenzenesulfonate and 4,4'-dihydroxydiphenyl sulfone is 6:4, the total molar mass of 4,4'-dihydroxydiphenyl sulfone and potassium 2,5-dihydroxybenzenesulfonate is in the molar ratio of 2,6-difluorobenzonitrile to 1:1, and potassium carbonate is kept in excess of 20% relative to 2,6-difluorobenzonitrile.

[0036] In a preferred embodiment of the present invention, in step (1), each gram of the mixture powder is dissolved in (1~1.2) mL of N-methylpyrrolidone solvent; in the mixed solvent, the volume ratio of N-methylpyrrolidone to toluene is 3:1.

[0037] In a preferred embodiment of the present invention, in step (1), the temperature for dehydration of the reactants is 135~140°C. o C, the buoyancy temperature is 165°C. o C, polymerization temperature is 180 o C. During the buoyancy phase, toluene and water in the distributor are released at a rate of 5 mL / 30 min.

[0038] In a preferred embodiment of the present invention, in step (1), after the solid product is pulverized, it is first soaked in an organic solvent such as acetone / ethanol to remove unreacted monomers in the system, and then washed multiple times with deionized water until neutral to remove acid and unreacted potassium salts.

[0039] In a preferred embodiment of the present invention, in step (2), the volume ratio of deionized water in the mixed solvent to the volume ratio of the mixed solvent is 0.1 to 0.15.

[0040] In a preferred embodiment of the present invention, in step (2), the concentration of the sulfonated polyarylene ether sulfone transparent solution A is 5-7 mg / mL.

[0041] In a preferred embodiment of the present invention, in step (2), the concentration of sulfonated cobalt phthalocyanine dispersion B is 1-4 mg / mL.

[0042] In a preferred embodiment of the present invention, in step (2), 9-13 mL of N,N-dimethylacetamide and 1-2 mL of deionized water are added to every 1 g of sulfonated polyarylether nitrile powder.

[0043] In a preferred embodiment of the present invention, the heat treatment conditions for the composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane in step (3) are 80°C. o C, 100 o C, 120 o C, 140 o C and 160 o C for 2 hours each; In a preferred embodiment of the present invention, the mass fraction of cobalt sulfonated phthalocyanine in the composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane in step (3) is 5-20 wt%.

[0044] In a preferred embodiment of the present invention, the thickness of the composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane in step (3) is 40-60 μm.

[0045] In a preferred embodiment of the present invention, in step (3), the acid used to soak the composite sulfonated polyarylene ether sulfone proton exchange membrane is dilute hydrochloric acid or dilute sulfuric acid with a concentration of 1 mol / L. -1 .

[0046] To better understand the present invention, the following embodiments are provided for further detailed description of the present invention, but they should not be construed as limiting the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above-described invention are also considered to fall within the protection scope of the present invention.

[0047] Example 1: (1) Preparation of sulfonated polyarylene ether nitrile sulfone resin 17.806 g of 2,6-difluorobenzonitrile, 11.262 g of 4,4'-dihydroxydiphenyl sulfone, and 9.610 g of potassium 2,5-dihydroxybenzenesulfonate were used as reactants, and 21.227 g of potassium carbonate was used as a catalyst. These were added to a mixed solvent of 65 mL N-methylpyrrolidone and 21 mL toluene, and the mixture was stirred at a concentration of 5... oThe heating rate of C / min raised the oil bath temperature to 135~140. o C, and the reaction was continued at this temperature range for 4 h; then at 5 o The temperature continued to rise at a rate of C / min to 165 o The reaction was carried out at a constant temperature of C for 3 hours; finally, the reaction was carried out at 5°C. o The heating rate of C / min will raise the temperature to 180. o C. Continue stirring until the viscosity of the mixture no longer changes. Cool the mixture to 150°C. o C. Pour the obtained reaction solution into a 1 mol / L dilute hydrochloric acid / dilute sulfuric acid solution, stir, and soak in the 1 mol / L dilute hydrochloric acid / dilute sulfuric acid solution for 24 h. Grind it into powder using a pulverizer, and soak the powder in an acetone / ethanol solution for 12 h. After washing and filtration, wash with deionized water 3-5 times until the solution is neutral. Place the washed powder in a vacuum oven and dry for 48 h to obtain sulfonated polyarylene ether nitrile sulfone proton exchange resin.

[0048] (2) Preparation of sulfonated cobalt phthalocyanine / sulfonated polyarylene ether nitrile sulfone proton exchange membrane 0.95 g of sulfonated polyarylene ether nitrile sulfone was proton exchanged and dissolved in 10 mL of a mixed solvent (2 mL of deionized water and 8 mL of N,N-dimethylacetamide), and then heated at 160 °C. o C, 200 r min -1 The mixture was stirred and refluxed for 3 hours to form a clear solution. Simultaneously, 0.05 g of sulfonated cobalt phthalocyanine was dispersed in 5 mL of N,N-dimethylacetamide and sonicated at 100 W for 2 hours at room temperature to form a uniformly dispersed solution. The dispersion of sulfonated cobalt phthalocyanine was then slowly added dropwise to the sulfonated polyarylene ether sulfonate clear solution and stirred at 50 °C. o C, Ultrasound at 100 W power with assisted 200-300 r / min -1 The mixture was mechanically stirred and heated for 4 hours. Then, the mixture was dropped onto a clean, level glass substrate and placed at 80°C. o Heat treatment in oven C for 2 hours at 100°C. o C, 120 o C, 140 o C and 160 o After heat treatment at C for 2 h, the film was allowed to cool naturally to room temperature, and then immersed in 1 mol L... -1 The membrane was immersed in a dilute acid solution for 24 hours; the membrane surface was rinsed repeatedly with deionized water, and the deionized water on the membrane surface was wiped clean with filter paper. It was then placed at 80°C. o A sulfonated polyarylene ether sulfonate composite proton exchange membrane with a sulfonated cobalt phthalocyanine mass fraction of 5 wt% can be obtained by drying in a vacuum oven at C for 36 h.

[0049] The resulting sulfonated polyarylene ether nitrile sulfone composite proton exchange membrane with a cobalt sulfonated phthalocyanine mass fraction of 5 wt% exhibited a water absorption rate of 20.51% and a swelling rate of 14.74% at room temperature. Its tensile strengths in the dry and wet states were 71.26 MPa and 57.93 MPa, respectively; and its proton conductivity was 0.066 S cm⁻¹. -1 Methanol permeability and selectivity are respectively .

[0050] Example 2: (1) Preparation of sulfonated polyarylene ether nitrile sulfone resin 17.806 g of 2,6-difluorobenzonitrile, 11.262 g of 4,4'-dihydroxydiphenyl sulfone, and 9.610 g of potassium 2,5-dihydroxybenzenesulfonate were used as reactants, and 21.227 g of potassium carbonate was used as a catalyst. These were added to a mixed solvent of 65 mL N-methylpyrrolidone and 21 mL toluene, and the mixture was stirred at a concentration of 5... o The heating rate of C / min raised the oil bath temperature to 135~140. o C, and the reaction was continued at this temperature range for 4 h; then at 5 o The temperature continued to rise at a rate of C / min to 165 o The reaction was carried out at a constant temperature of C for 3 hours; finally, the reaction was carried out at 5°C. o The heating rate of C / min will raise the temperature to 180. o C. Continue stirring until the viscosity of the mixture no longer changes. Cool the mixture to 150°C. o C. Pour the obtained reaction solution into a 1 mol / L dilute hydrochloric acid / dilute sulfuric acid solution, stir, and soak in the 1 mol / L dilute hydrochloric acid / dilute sulfuric acid solution for 24 h. Grind it into powder using a pulverizer, and soak the powder in an acetone / ethanol solution for 12 h. After washing and filtration, wash with deionized water 3-5 times until the solution is neutral. Place the washed powder in a vacuum oven and dry for 48 h to obtain sulfonated polyarylene ether nitrile sulfone proton exchange resin.

[0051] (2) Preparation of sulfonated cobalt phthalocyanine / sulfonated polyarylene ether nitrile sulfone proton exchange membrane 0.9 g of sulfonated polyarylene ether nitrile sulfone was proton exchanged and dissolved in 10 mL of a mixed solvent (2 mL of deionized water and 8 mL of N,N-dimethylacetamide), and then heated at 160 °C. o C, 200 r min -1 The mixture was stirred and refluxed for 3 hours to form a clear solution. Simultaneously, 0.1 g of sulfonated cobalt phthalocyanine was dispersed in 5 mL of N,N-dimethylacetamide and sonicated at 100 W for 2 hours at room temperature to form a uniformly dispersed solution. The dispersion of sulfonated cobalt phthalocyanine was then slowly added dropwise to the sulfonated polyarylene ether sulfonate clear solution and stirred at 50 °C.o C, Ultrasound at 100 W power with assisted 200-300 r / min -1 The mixture was mechanically stirred and heated for 4 hours. Then, the mixture was dropped onto a clean, level glass substrate and placed at 80°C. o Heat treatment in oven C for 2 hours at 100°C. o C, 120 o C, 140 o C and 160 o After heat treatment at C for 2 h, the film was allowed to cool naturally to room temperature, and then immersed in 1 mol L... -1 The membrane was immersed in a dilute acid solution for 24 hours; the membrane surface was rinsed repeatedly with deionized water, and the deionized water on the membrane surface was wiped clean with filter paper. It was then placed at 80°C. o A sulfonated polyarylene ether sulfonate composite proton exchange membrane with a sulfonated cobalt phthalocyanine mass fraction of 10 wt% can be obtained by drying in a vacuum oven at C for 36 h.

[0052] The resulting sulfonated polyarylene ether nitrile sulfone composite proton exchange membrane with a cobalt phthalocyanine mass fraction of 10 wt% exhibited a water absorption rate of 22.38% and a swelling rate of 15.56% at room temperature. Its tensile strengths in the dry and wet states were 68.62 MPa and 43.86 MPa, respectively; and its proton conductivity was 0.072 S cm⁻¹. -1 Methanol permeability and selectivity are respectively .

[0053] Example 3: (1) Preparation of sulfonated polyarylene ether nitrile sulfone resin 17.806 g of 2,6-difluorobenzonitrile, 11.262 g of 4,4'-dihydroxydiphenyl sulfone, and 9.610 g of potassium 2,5-dihydroxybenzenesulfonate were used as reactants, and 21.227 g of potassium carbonate was used as a catalyst. These were added to a mixed solvent of 65 mL N-methylpyrrolidone and 21 mL toluene, and the mixture was stirred at a concentration of 5... o The heating rate of C / min raised the oil bath temperature to 135~140. o C, and the reaction was continued at this temperature range for 4 h; then at 5 o The temperature continued to rise at a rate of C / min to 165 o The reaction was carried out at a constant temperature of C for 3 hours; finally, the reaction was carried out at 5°C. o The heating rate of C / min will raise the temperature to 180. o C. Continue stirring until the viscosity of the mixture no longer changes. Cool the mixture to 150°C. oC. Pour the obtained reaction solution into a 1 mol / L dilute hydrochloric acid / dilute sulfuric acid solution, stir, and soak in the 1 mol / L dilute hydrochloric acid / dilute sulfuric acid solution for 24 h. Grind it into powder using a pulverizer, and soak the powder in an acetone / ethanol solution for 12 h. After washing and filtration, wash with deionized water 3-5 times until the solution is neutral. Place the washed powder in a vacuum oven and dry for 48 h to obtain sulfonated polyarylene ether nitrile sulfone proton exchange resin.

[0054] (2) Preparation of sulfonated cobalt phthalocyanine / sulfonated polyarylene ether nitrile sulfone proton exchange membrane 0.85 g of sulfonated polyarylene ether nitrile sulfone was proton exchanged and dissolved in 10 mL of a mixed solvent (2 mL of deionized water and 8 mL of N,N-dimethylacetamide), and then dissolved at 160 °C. o C, 200 r min -1 The mixture was stirred and refluxed for 3 hours to form a clear solution. Simultaneously, 0.15 g of sulfonated cobalt phthalocyanine was dispersed in 5 mL of N,N-dimethylacetamide and sonicated at 100 W for 2 hours at room temperature to form a uniformly dispersed solution. The dispersion of sulfonated cobalt phthalocyanine was then slowly added dropwise to the sulfonated polyarylene ether sulfonate clear solution and stirred at 50 °C. o C, Ultrasound at 100 W power with assisted 200-300 r / min -1 The mixture was mechanically stirred and heated for 4 hours. Then, the mixture was dropped onto a clean, level glass substrate and placed at 80°C. o Heat treatment in oven C for 2 hours at 100°C. o C, 120 o C, 140 o C and 160 o After heat treatment at C for 2 h, the film was allowed to cool naturally to room temperature, and then immersed in 1 mol L... -1 The membrane was immersed in a dilute acid solution for 24 hours; the membrane surface was rinsed repeatedly with deionized water, and the deionized water on the membrane surface was wiped clean with filter paper. It was then placed at 80°C. o A sulfonated polyarylene ether sulfonate composite proton exchange membrane with a cobalt phthalocyanine mass fraction of 15 wt% can be obtained by drying in a vacuum oven at C for 36 h.

[0055] The resulting sulfonated polyarylene ether nitrile sulfone composite proton exchange membrane with a cobalt phthalocyanine mass fraction of 15 wt% exhibited a water absorption rate of 23.71% and a swelling rate of 17.13% at room temperature. Its tensile strengths in the dry and wet states were 60.62 MPa and 29.70 MPa, respectively; and its proton conductivity was 0.065 S / cm. -1 Methanol permeability and selectivity are respectively .

[0056] Example 4: (1) Preparation of sulfonated polyarylene ether nitrile sulfone resin 17.806 g of 2,6-difluorobenzonitrile, 11.262 g of 4,4'-dihydroxydiphenyl sulfone, and 9.610 g of potassium 2,5-dihydroxybenzenesulfonate were used as reactants, and 21.227 g of potassium carbonate was used as a catalyst. These were added to a mixed solvent of 65 mL N-methylpyrrolidone and 21 mL toluene, and the mixture was stirred at a concentration of 5... o The heating rate of C / min raised the oil bath temperature to 135~140. o C, and the reaction was continued at this temperature range for 4 h; then at 5 o The temperature continued to rise at a rate of C / min to 165 o The reaction was carried out at a constant temperature of C for 3 hours; finally, the reaction was carried out at 5°C. o The heating rate of C / min will raise the temperature to 180. o C. Continue stirring until the viscosity of the mixture no longer changes. Cool the mixture to 150°C. o C. Pour the obtained reaction solution into a 1 mol / L dilute hydrochloric acid / dilute sulfuric acid solution, stir, and soak in the 1 mol / L dilute hydrochloric acid / dilute sulfuric acid solution for 24 h. Grind it into powder using a pulverizer, and soak the powder in an acetone / ethanol solution for 12 h. After washing and filtration, wash with deionized water 3-5 times until the solution is neutral. Place the washed powder in a vacuum oven and dry for 48 h to obtain sulfonated polyarylene ether nitrile sulfone proton exchange resin.

[0057] (2) Preparation of sulfonated cobalt phthalocyanine / sulfonated polyarylene ether nitrile sulfone proton exchange membrane 0.8 g of sulfonated polyarylene ether nitrile sulfone was proton exchanged and dissolved in 10 mL of a mixed solvent (2 mL of deionized water and 8 mL of N,N-dimethylacetamide), and then heated at 160 °C. o C, 200 r min -1 The mixture was stirred and refluxed for 3 hours to form a clear solution. Simultaneously, 0.2 g of sulfonated cobalt phthalocyanine was dispersed in 5 mL of N,N-dimethylacetamide and sonicated at 100 W for 2 hours at room temperature to form a uniformly dispersed solution. The dispersion of sulfonated cobalt phthalocyanine was then slowly added dropwise to the sulfonated polyarylene ether nitrile sulfone clear solution and stirred at 50 °C. o C, Ultrasound at 100 W power with assisted 200-300 r / min -1 The mixture was mechanically stirred and heated for 4 hours. Then, the mixture was dropped onto a clean, level glass substrate and placed at 80°C. o Heat treatment in oven C for 2 hours at 100°C. o C, 120 o C, 140 o C and 160 oAfter heat treatment at C for 2 h, the film was allowed to cool naturally to room temperature, and then immersed in 1 mol L... -1 The membrane was immersed in a dilute acid solution for 24 hours; the membrane surface was rinsed repeatedly with deionized water, and the deionized water on the membrane surface was wiped clean with filter paper. It was then placed at 80°C. o A sulfonated polyarylene ether sulfonate composite proton exchange membrane with a sulfonated cobalt phthalocyanine mass fraction of 20 wt% can be obtained by drying in a vacuum oven at C for 36 h.

[0058] The resulting sulfonated polyarylene ether nitrile sulfone composite proton exchange membrane with a cobalt phthalocyanine mass fraction of 20 wt% exhibited a water absorption rate of 25.91% and a swelling rate of 19.65% at room temperature. Its tensile strengths in the dry and wet states were 58.73 MPa and 26.65 MPa, respectively; and its proton conductivity was 0.052 S cm⁻¹. -1 Methanol permeability and selectivity are respectively .

[0059] Test case (1) Preparation of sulfonated polyarylene ether nitrile sulfone resin 17.806 g of 2,6-difluorobenzonitrile, 11.262 g of 4,4'-dihydroxydiphenyl sulfone, and 9.610 g of potassium 2,5-dihydroxybenzenesulfonate were used as reactants, and 21.227 g of potassium carbonate was used as a catalyst. These were added to a mixed solvent of 65 mL N-methylpyrrolidone and 21 mL toluene, and the mixture was stirred at a concentration of 5... o The heating rate of C / min raised the oil bath temperature to 135~140. o C, and the reaction was continued at this temperature range for 4 h; then at 5 o The temperature continued to rise at a rate of C / min to 165 o The reaction was carried out at a constant temperature of C for 3 hours; finally, the reaction was carried out at 5°C. o The heating rate of C / min will raise the temperature to 180. o C. Continue stirring until the viscosity of the mixture no longer changes. Cool the mixture to 150°C. o C. Pour the obtained reaction solution into a 1 mol / L dilute hydrochloric acid / dilute sulfuric acid solution, stir, and soak in the 1 mol / L dilute hydrochloric acid / dilute sulfuric acid solution for 24 h. Grind it into powder using a pulverizer, and soak the powder in an acetone / ethanol solution for 12 h. After washing and filtration, wash with deionized water 3-5 times until the solution is neutral. Place the washed powder in a vacuum oven and dry for 48 h to obtain sulfonated polyarylene ether nitrile sulfone proton exchange resin.

[0060] (2) Preparation of sulfonated polyarylene ether nitrile sulfone proton exchange membrane 1 g of sulfonated polyarylene ether sulfone proton exchange resin was dissolved in 15 mL of a mixed solvent (2 mL of deionized water and 13 mL of N,N-dimethylacetamide) at 160 °C. o C, 200 r min -1 The mixture was stirred and refluxed for 3 hours. The clear solution was then dropped onto a clean, level glass substrate, allowing it to naturally flow and form a film, which was then placed at 80°C. o Heat treatment in oven C for 2 hours at 100°C. o C, 120 o C, 140 o C and 160 o After heat treatment at C for 2 h, the film was allowed to cool naturally to room temperature, and then immersed in 1 mol L... -1 The membrane was immersed in a dilute acid solution for 24 hours; the membrane surface was rinsed repeatedly with deionized water, and the deionized water on the membrane surface was wiped clean with filter paper. It was then placed at 80°C. o The sulfonated polyarylene ether nitrile sulfone proton exchange membrane can be obtained by drying in a vacuum oven at C for 36 h.

[0061] The obtained sulfonated polyarylene ether nitrile sulfone proton exchange membrane had a water absorption rate of 20.46% and a swelling rate of 13.99% at room temperature. Its tensile strengths in the dry and wet states were 73.79 MPa and 61.88 MPa, respectively; the proton conductivity was 0.044 Scm. -1 Methanol permeability and selectivity are respectively .

[0062] Compared with Examples 1-4, the performance of Comparative Example 1 is significantly lower than that of the composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane disclosed in this invention. Therefore, the sulfonated cobalt phthalocyanine / sulfonated polyarylene ether nitrile sulfone composite proton exchange membrane disclosed in this invention exhibits high proton conductivity, high selectivity, and excellent mechanical properties.

[0063] The following is in conjunction with the appendix Figures 1-4 The technical solution of the present invention will be further described below.

[0064] Figure 1 This is a schematic diagram of the preparation process of sulfonated polyarylene ether nitrile sulfone resin. Ar1 is 4,4'-dihydroxydiphenyl sulfone, Ar2 is potassium 2,5-dihydroxybenzenesulfonate, and n is 0.4.

[0065] Figure 2 This is an electron micrograph of a composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane. The composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane can be bent and folded into a columnar shape without breaking, exhibiting characteristics of being lightweight and highly flexible.

[0066] Figure 3 The mechanical properties of the composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane under both dry and wet conditions are described.Figure 3 It can be observed that the tensile strength and elastic modulus of the composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane decrease in both dry and wet conditions, and this decrease increases with the increase of the cobalt sulfonated phthalocyanine content. However, even when the cobalt sulfonated phthalocyanine content is increased to 20 wt%, its tensile strength and elastic modulus can still reach 58.73 MPa and 1383.22 MPa, respectively; in the wet condition, they can reach 26.65 MPa and 642.75 MPa, respectively, exhibiting good dry and wet mechanical properties.

[0067] Figure 4 This refers to the proton conductivity of a composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane at different temperatures. Figure 4 It can be observed that at room temperature, when the content of cobalt sulfonated phthalocyanine is within 10 wt%, the proton conductivity of the membrane increases with the increase of the cobalt sulfonated phthalocyanine content, reaching a maximum of 0.0723 S cm. -1 ; while in 80 o Even at high temperatures (C), its proton conductivity remains at 0.1769 S cm⁻¹. -1 It exhibits excellent proton conductivity. However, when the content of cobalt sulfonated phthalocyanine exceeds 10 wt%, its proton conductivity decreases slightly, a phenomenon observed at 80 wt%. o This is especially evident at time C.

[0068] Figure 5 It describes the methanol permeability and selectivity of a composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane at room temperature. Figure 5 As can be seen, at room temperature, when the content of sulfonated cobalt phthalocyanine is within 10 wt%, the selectivity of the composite proton exchange membrane increases with the increase of the content of sulfonated cobalt phthalocyanine, reaching a maximum of [missing value]. The selectivity is significantly higher than that of pure sulfonated polyarylene ether nitrile sulfone matrix under the same conditions. However, when the content of sulfonated cobalt phthalocyanine exceeds 10 wt%, its selectivity tends to decrease, and this phenomenon is particularly obvious when the content of sulfonated cobalt phthalocyanine is 20 wt%.

[0069] In summary, to achieve high proton conductivity, good dimensional stability, and excellent mechanical properties simultaneously, the content of cobalt sulfonated phthalocyanine must be controlled within 5-10 wt% for composite sulfonated polyarylether nitrile sulfone proton exchange membranes.

[0070] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane, characterized in that, The steps are as follows: Step 1: Synthesize sulfonated polyarylene ether nitrile sulfone; Step 2: Add the sulfonated polyarylene ether nitrile sulfone obtained in Step 1 to a mixed solvent of N,N-dimethylacetamide and deionized water, and heat at 160°C. o C, 200 r min -1 The reaction was stirred for 3 h to obtain a hot solution of sulfonated polyarylene ether sulfone. A certain amount of sulfonated cobalt phthalocyanine was added to N,N-dimethylacetamide and ultrasonically dispersed at room temperature for 2 h to obtain a sulfonated cobalt phthalocyanine dispersion. The sulfonated cobalt phthalocyanine dispersion was added to the sulfonated polyarylene ether nitrile sulfone hot solution at 160°C. o C, 200 r min -1 Under the condition of continuous ultrasonic stirring for 4 h, a hot solution of sulfonated cobalt phthalocyanine / sulfonated polyarylene ether sulfone mixture was obtained. Step 3: The hot solution of the sulfonated cobalt phthalocyanine / sulfonated polyarylene ether nitrile sulfone mixture obtained in Step 2 is used to form a film by casting to obtain a sulfonated cobalt phthalocyanine / sulfonated polyarylene ether nitrile sulfone composite film; Step 4: Allow the mixture to cool naturally to room temperature, then immerse the sulfonated cobalt phthalocyanine / sulfonated polyarylene ether sulfone composite film obtained in Step 3 in 1 mol L... -1 The membrane surface was rinsed repeatedly with deionized water after being immersed in dilute sulfuric acid for 24 hours. The deionized water on the membrane surface was then wiped clean with filter paper to obtain an acidic sulfonated cobalt phthalocyanine / sulfonated polyarylene ether nitrile sulfone composite proton exchange membrane with a thickness of 40-60 μm and a sulfonated cobalt phthalocyanine content of 5-20 wt%.

2. The method for preparing the composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane according to claim 1, characterized in that, The specific process for synthesizing sulfonated polyarylene ether sulfone in step 1 is as follows: 1.1 In a three-necked flask, 2,6-difluorobenzonitrile, 4,4'-dihydroxydiphenyl sulfone and potassium 2,5-dihydroxybenzenesulfonate were added sequentially as reactants, and potassium carbonate was added as a catalyst to obtain a mixed powder. 1.2 Add a mixture of N-methylpyrrolidone and toluene to the powdered mixture obtained in step 1.1 to obtain mixed solution A; 1.3 The mixed solution A obtained in step 1.2 is heated at 135~140°C. o The reaction was mechanically stirred in a constant-temperature oil bath at C for 4 h; then the temperature was further increased to 165 °C. o The reaction was carried out at a constant temperature of C for 3 hours; finally, the temperature was raised to 180°C. o C. Continue stirring until the viscosity of the mixture no longer changes; cool the mixture to 150°C. o C. Pour the obtained reaction solution into a 1 mol / L dilute hydrochloric acid / dilute sulfuric acid solution, stir, and obtain solid A; 1.4 After soaking the solid A obtained in step 1.3 in a 1 mol / L dilute hydrochloric acid / dilute sulfuric acid solution for 24 h, the solid A was pulverized into powder using a pulverizer, and the powder was soaked in 80-100 ml of acetone / ethanol for 12 h. After washing and filtration, it was washed 3-5 times with deionized water until the solution was neutral. The washed powder was placed in a vacuum oven and dried for 48 h to obtain the sulfonated polyarylene ether nitrile sulfone.

3. The method for preparing the composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane according to claim 2, characterized in that, In step 1.1, the molar ratio of potassium 2,5-dihydroxybenzenesulfonate and 4,4'-dihydroxydiphenyl sulfone is 6:4, the total molar amount of 4,4'-dihydroxydiphenyl sulfone and potassium 2,5-dihydroxybenzenesulfonate is in a molar ratio of 1:1 to 2,6-difluorobenzonitrile, and the molar ratio of potassium carbonate to 2,6-difluorobenzonitrile is 1.2:

1.

4. The method for preparing the composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane according to claim 2, characterized in that, In step 1.2, each gram of the mixture powder is dissolved in (1~1.2) mL of N-methylpyrrolidone solvent; in the mixed solvent, the volume ratio of N-methylpyrrolidone to toluene is 3:

1.

5. The method for preparing the composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane according to claim 1, characterized in that, In step 2, the mass ratio of sulfonated cobalt phthalocyanine in the composite material is 0~20 wt%, and 9~13 mL of N,N-dimethylacetamide and 1~2 mL of deionized water are added to every 1g of sulfonated polyarylene ether nitrile sulfone resin.

6. The method for preparing the composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane according to claim 1, characterized in that, In step 3, the temperature control process for the casting method is as follows: [The temperature is controlled at 80°C.] o C, 100 o C, 120 o C, 140 o C and 160 o Each temperature is maintained at C for 2 hours.

7. A composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane prepared by the method according to any one of claims 1 to 6, characterized in that, The composite sulfonated polyarylene ether nitrile sulfone proton exchange membrane is a proton exchange membrane with high proton conductivity, high selectivity and good mechanical properties.

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