An antioxidant non-fluorine ion exchange membrane, its preparation method, and its application in functional membranes.

Abstract

This invention relates to an antioxidant non-fluorinated ion exchange membrane, its preparation method, and its application in functional membranes, belonging to the field of functional polymer materials technology. The invention uses N-phenyl(4,4'-dichlorodiphenyl)ketone imine and sodium sulfonate monomers as raw materials, and prepares a Schiff base-containing polyaryl ketone precursor polymer through Yamamoto coupling homopolymerization. After dissolving and casting the polyaryl ketone precursor polymer into a membrane, a polyaryl ketone ion exchange membrane is prepared through hydrolysis in an acidic environment, i.e., an antioxidant non-fluorinated ion exchange membrane material. Due to its excellent antioxidant stability, good dimensional stability, and solution processability, this antioxidant non-fluorinated ion exchange membrane material can be applied in functional membrane and other fields.

Description

Technical Field

[0001] This invention belongs to the field of functional polymer materials technology, specifically relating to an antioxidant non-fluorine ion exchange membrane, its preparation method, and its application in functional membranes. Background Technology

[0002] Sulfonated polyaryletherketone (PAEK) materials, as high-performance polymer materials, possess advantages such as low cost, high efficiency in ion exchange, good mechanical properties, high thermal stability, low fuel permeability, and processability, making them widely applicable in fuel cells, water treatment, biomedicine, and composite materials. While currently considered the most promising alternative to perfluorosulfonic acid polymers for proton exchange membranes, they still face challenges in achieving a balance between poor oxidation stability and proton conductivity and dimensional stability, thus limiting their application in fuel cells.

[0003] Sulfonated polyaryletherketone (PAK) materials exhibit poor antioxidant stability as proton exchange membranes (PEMs) due to the presence of ether bonds. To improve the antioxidant stability of PEMs, we designed a PAK polymer without ether bonds. This polymer exhibits good film-forming properties and, compared to PAK materials, demonstrates higher antioxidant and dimensional stability, making it an ideal material for PEMs. Summary of the Invention

[0004] The purpose of this invention is to design an antioxidant non-fluorinated ion exchange membrane, its preparation method, and its application in functional membranes, starting from the molecular structure. This invention uses N-phenyl(4,4'-dichlorodiphenyl)ketone imine and sodium sulfonate monomers as raw materials, and prepares a Schiff base-containing polyaryl ketone precursor polymer through Yamamoto coupling homopolymerization. After dissolving and casting the polyaryl ketone precursor polymer into a membrane, a polyaryl ketone ion exchange membrane, i.e., an antioxidant non-fluorinated ion exchange membrane material, is prepared through a hydrolysis reaction in an acidic environment. This antioxidant non-fluorinated ion exchange membrane has advantages such as excellent antioxidant stability, good dimensional stability, and solution processability, and can be applied in functional membranes and other fields.

[0005] The present invention discloses a novel antioxidant non-fluorine ion exchange membrane, the structural formula of which is shown in (I):

[0006]

[0007] In equation (I), A is

[0008] x and y represent the molar proportions of each component in the polymer chain, x + y = 1, where 0 < x < 1.

[0009] The preparation method of a novel antioxidant non-fluorine ion exchange membrane according to the present invention comprises the following steps:

[0010] (1) Preparation of sodium (2,5-dichlorobenzoyl)benzenesulfonate monomer (see document: SGJo, THKim, SJYoon, SGOh, MSCha, HYShin, JMAhn, JYLee, YTHong, Synthesis and investigation of random-structured ionomers with highly sulfonated multi-phenyl pendants for electrochemical applications, Journal of Membrane Science 510(2016)326-337. https: / / doi.org / 10.1016 / j.memsci.2016.03.018):

[0011] Under N2 protection, 1 g of solid 2,5-dichlorobenzoic acid and 2-3 mL of thionyl chloride were added to a two-necked flask, followed by the addition of 0.2-0.5 mL of pyridine. The mixture was heated under reflux at 60-80 °C for 3-5 h, during which the reaction system changed from a white turbid liquid to a clear and transparent solution. Excess thionyl chloride solvent was then removed by vacuum distillation to obtain a colorless and transparent solution. Upon cooling, a white solid 2,5-dichlorobenzoyl chloride was obtained.

[0012] Under N2 protection, solid 2,5-dichlorobenzoyl chloride was added to a two-necked flask. 1 g of 2,5-dichlorobenzoyl chloride was added to 2-3 mL of benzene as a solvent, followed by the addition of solid anhydrous aluminum chloride. The molar ratio of 2,5-dichlorobenzoyl chloride to anhydrous aluminum chloride was 1:1-1.5. The mixture was heated under reflux at 60-70 °C for 5-7 h, during which the reaction system changed from a colorless, transparent solution to a bright yellow. After the reaction was completed, the solution was poured into a 1-4 M glacial hydrochloric acid aqueous solution. The separated organic phase was washed with 1-5 M NaOH solution and ultrapure water until neutral. Excess benzene was removed by vacuum distillation. The crude product was recrystallized 2-3 times with petroleum ether to obtain white 2,5-dichlorobenzophenone crystals.

[0013] Under N2 protection, 1 g of solid 2,5-dichlorobenzophenone and 1.5–3 mL of fuming sulfuric acid with a SO3 content of 20% were added to a two-necked flask and reacted at 80–100 °C for 8–16 h. After the reaction was completed, the solution was poured into ice-cold ultrapure water, and 3–5 M NaOH solution was added dropwise until a large amount of white precipitate formed. The solution was filtered to obtain the crude product. The crude product was recrystallized 2–3 times with ultrapure water to obtain a white sodium (2,5-dichlorobenzoyl)benzenesulfonate monomer, the reaction structure of which is shown below:

[0014]

[0015] (2) Preparation of sodium 4-(2,5-dichlorobenzoyl)-[1,1'-biphenyl]-2,4'-disulfonic acid monomer (JP 2006-298794A, Aromatic sulfonic acid derivatives, polymers containing them, and solid polymer electrolytes and proton conducting membranes containing them):

[0016] Under N2 protection, the solid 2,5-dichlorobenzoyl chloride synthesized in step (1), biphenyl and anhydrous aluminum chloride were added to a two-necked flask in a molar ratio of 1:1 to 1.2:1 to 1.5. Trichloromethane was added as the reaction solvent, and the mixture was heated to reflux at 70 to 80 °C for 4 to 6 hours. The reaction system remained a dark purple solution throughout. After the reaction, the solution was poured into a 1 to 4 M glacial hydrochloric acid aqueous solution. After separation, the organic phase was washed with 1 to 5 M NaOH solution and ultrapure water until neutral. Trichloromethane was removed by vacuum rotary evaporation. The crude product was recrystallized 2 to 3 times with petroleum ether to obtain [1,1'-biphenyl]-4-yl(2,5-dichlorophenyl) methyl ketone monomer, which was a white crystal.

[0017] Under N2 protection, 1 g of [1,1'-biphenyl]-4-yl(2,5-dichlorophenyl) methyl ketone monomer and 1.5–3 mL of fuming sulfuric acid with a SO3 content of 20% were added to a two-necked flask and reacted at 80–100 °C for 8–16 h. After the reaction was completed, the solution was poured into ice-cold ultrapure water, and 3–5 M NaOH solution was added dropwise until a large amount of white precipitate formed. The solution was filtered to obtain the crude product. The crude product was recrystallized 2–3 times with ultrapure water to obtain a white sodium 4-(2,5-dichlorobenzoyl)-[1,1'-biphenyl]-2,4'-disulfonate monomer, the reaction structure of which is shown below:

[0018]

[0019] (3) Preparation of polyaryl ketone precursor polymers:

[0020] N-phenyl(4,4'-dichlorodiphenyl) ketimide, sodium (2,5-dichlorobenzoyl)benzenesulfonate monomer prepared in step (1) or sodium 4-(2,5-dichlorobenzoyl)-[1,1'-biphenyl]-2,4'-disulfonate monomer prepared in step (2), 2,2'-bipyridine, and anhydrous potassium carbonate were added to a dry two-necked flask, and N2 was continuously introduced. For 0.5–2 h, anhydrous N,N-dimethylacetamide (DMAC), N,N'-dimethylformamide (DMF), N-methylpyrrolidone (NMP), or dimethyl sulfoxide (DMSO) are added to the flask as solvents using a syringe; after heating to 70–90 °C, bis(1,5-cyclooctadiene)nickel is added as a catalyst, and the temperature is maintained for 4–8 h; the molar ratio of the total amount of N-phenyl(4,4'-dichlorodiphenyl)one imine and sodium sulfonate monomers to the bis(1,5-cyclooctadiene)nickel catalyst is 1:1–4, and the amount of N-phenyl(4,4'-dichlorodiphenyl)one imine monomer is not zero; bis(1,5 The molar ratio of cyclooctadiene (Ni) catalyst to 2,2'-bipyridine was 1:1–3, and the solvent mass was 2–10 times the total mass of the reactants. After the reaction was completed and cooled to room temperature, the resulting mixture was discharged into anhydrous ethanol. The product was washed 5–6 times with anhydrous ethanol and ultrapure water, respectively, and finally dried under vacuum at 50–70 °C to obtain the crude polyaryl ketone precursor polymer. The crude product was then dissolved in 5–10 mL of NMP solvent, and insoluble impurities were removed by sintering. After drying at 70–100 °C to remove the solvent, the polyaryl ketone precursor polymer was obtained with a yield of 60–80%. The reaction formula and product structure are shown below:

[0021]

[0022] A is independently selected

[0023] (4) Preparation of polyaryl ketone polymers:

[0024] The polyaryl ketone precursor polymer prepared in step (3) was placed in a 0.5–2.0 M acid solution (sulfuric acid or hydrochloric acid solution) and soaked at 70–100 °C for 8–15 h. After filtration, the polymer was washed with ultrapure water until the pH was 6.5–8.5, and then vacuum dried at 70–90 °C to obtain the polyaryl ketone polymer. The reaction formula and product structure are shown below:

[0025]

[0026] A is independently selected

[0027] x and y represent the molar proportions of each component in the polymer chain, x + y = 1, and 0 < x < 1;

[0028] (5) Preparation of homogeneous membrane of polyaryl ketone precursor:

[0029] Dissolve 0.2–0.5 g of the polyaryl ketone precursor polymer prepared in step (3) in 5–10 mL of NMP, DMSO, DMF or DMAC solvent. After complete dissolution and filtration through a sand core, cast the polymer onto a glass plate. Then, dry the polymer at 75–85 °C and 95–120 °C for 20–30 h to remove the solvent, thereby obtaining a homogeneous polyaryl ketone precursor membrane with a thickness of 10–60 μm.

[0030] (6) Preparation of polyaryl ketone ion exchange membranes:

[0031] Take the homogeneous polyaryl ketone precursor membrane prepared in step (5) and place it in a 0.5-2.0M acid solution. Soak it at 70-90℃ for 8-15 hours. Then wash it with ultrapure water until the pH is 6.5-8.5. Then dry it at 70-90℃ under vacuum for 10-15 hours to obtain a polyaryl ketone ion exchange membrane, namely an antioxidant non-fluorine ion exchange membrane with a thickness of 10-60 μm. Attached Figure Description

[0032] Figure 1 The figure shows the 1H NMR spectrum of the sodium (2,5-dichlorobenzoyl)benzenesulfonate monomer prepared in Example 1 (using deuterated DMSO as the NMR reagent); as shown in the figure, the peak shift analysis indicates that the monomer has been successfully prepared.

[0033] Figure 2 The figure shows the 1H NMR spectrum of the sodium 4-(2,5-dichlorobenzoyl)-[1,1'-biphenyl]-2,4'-disulfonate monomer prepared in Example 2 (using deuterated DMSO as the NMR reagent); as shown in the figure, the peak shift analysis indicates that the monomer has been successfully prepared.

[0034] Figure 3 This is the infrared spectrum of the polyaryl ketone precursor polymer 1 (x = 45%) prepared in Example 3; at 1032 cm⁻¹ -1 and 1068cm -1 The characteristic absorption peak of the sulfonic acid group appeared at 1661 cm⁻¹. -1 The presence of a carbonyl characteristic absorption peak at the point indicates the successful conduct of the coupling reaction, demonstrating the successful preparation of the polyaryl ketone precursor polymer.

[0035] Figure 4 This is the infrared spectrum of the polyaryl ketone precursor polymer II (x = 45%) prepared in Example 6; at 1033 cm⁻¹ -1 and 1071cm -1 The characteristic absorption peak of the sulfonic acid group appeared at 1643 cm⁻¹. -1The presence of a carbonyl characteristic absorption peak at the point indicates the successful conduct of the coupling reaction, demonstrating that the polyaryl ketone precursor polymer II (x = 45%) was successfully prepared.

[0036] Figure 5 This is the infrared spectrum of the polyaryl ketone polymer (x = 45%) prepared in Example 9; at 1032 cm⁻¹ -1 and 1067cm -1 The characteristic absorption peak of the sulfonic acid group appeared at 1651 cm⁻¹. -1 A carbonyl characteristic absorption peak appeared at [location], compared to [other location]. Figure 3 The carbonyl characteristic absorption peak was significantly enhanced, which proved the successful hydrolysis reaction and indicated that the polyaryl ketone polymer (x = 45%) was successfully prepared.

[0037] Figure 6 This is the infrared spectrum of the polyaryl ketone polymer II (x = 45%) prepared in Example 10; at 1033 cm⁻¹ -1 and 1072cm -1 The characteristic absorption peak of the sulfonic acid group appeared at 1650 cm⁻¹. -1 A carbonyl characteristic absorption peak appeared at [location], compared to [other location]. Figure 4 The carbonyl characteristic absorption peak was significantly enhanced, proving the successful hydrolysis reaction and indicating that the polyaryl ketone polymer was successfully prepared.

[0038] Figure 7 These are photographs of the polyaryl ketone precursor homogeneous membrane prepared in Example 11 and the polyaryl ketone ion exchange membrane prepared in Example 12. Figure 7 a is a homogeneous membrane of polyaryl ketone precursor (x = 45%). Figure 7 b is a homogeneous membrane of polyaryl ketone precursor (x = 45%). Figure 7 c is a polyaryl ketone ion exchange membrane (x = 45%). Figure 7 d represents the second polyaryl ketone ion exchange membrane (x = 45%). The results show that the polymer prepared in this invention can form a film, unlike typical polyaryl ketones which are insoluble in common organic solvents and cannot form films. Detailed Implementation

[0039] Example 1

[0040] Preparation of 2,5-dichlorobenzoyl chloride monomer: Under N2 protection, 11.46 g (0.06 mol) of 2,5-dichlorobenzoic acid was weighed and placed in a 100 mL two-necked flask, and a spindle-shaped magnetic stirrer was added. At room temperature, using thionyl chloride as a solvent, 30 mL of thionyl chloride solution and 0.5 mL of pyridine solution were slowly added dropwise to a single-necked flask. After stirring at room temperature for 10 minutes, the oil bath temperature was set to 60 °C, and reflux was applied using a condenser. At this point, the system was a white turbid liquid. After heating at 60 °C for 3 hours, the white turbid liquid turned into a light yellow transparent liquid, indicating that the reaction was complete. Heating was then stopped, and the mixture was allowed to stand at room temperature before being removed. To obtain pure 2,5-dichlorobenzoyl chloride monomer, excess thionyl chloride solvent was removed by vacuum distillation. A vacuum distillation apparatus was set at 90 °C, and the thionyl chloride liquid was collected. After the solvent was evaporated to dryness, the colorless and transparent liquid in the bottle was 2,5-dichlorobenzoyl chloride monomer. Due to its low melting point, it was placed in a 0°C refrigerator to obtain a white 2,5-dichlorobenzoyl chloride solid. The crude solid product was filtered again to obtain white crystalline 2,5-dichlorobenzoyl chloride monomer in 90% yield. Its chemical structural formula is as follows:

[0041]

[0042] Preparation of 2,5-dichlorobenzophenone monomer. Under N2 protection, 12.57 g (0.06 mol) of 2,5-dichlorobenzoyl chloride monomer and 8.00 g (0.06 mol) of anhydrous AlCl3 solid were placed in a 100 mL two-necked flask. N2 was bubbled through the flask, and 22 mL (0.24 mol) of benzene solution was slowly added dropwise at room temperature. The reaction was vigorous immediately upon addition of benzene. The oil bath temperature was set to 70 °C. When the temperature reached 35 °C, the 2,5-dichlorobenzophenone monomer melted. When the temperature reached 50 °C, it became a clear, bright yellow solution. Heating was continued at 70 °C for 5 hours, then heating was stopped, and the solution was allowed to stand at room temperature before being removed. The reaction solution was poured into 100 mL (2M) of glacial hydrochloric acid aqueous solution to remove AlCl3. The resulting white emulsion was dissolved in 100 mL of CHCl3. The organic phase was washed with 10% NaOH solution and deionized water until neutral. The CHCl3 solvent was removed by vacuum rotary evaporation to obtain a white solid. Recrystallization three times with petroleum ether yielded a pure 2,5-dichlorobenzophenone monomer in 70% yield. Its chemical structure is as follows:

[0043]

[0044] Sodium (2,5-dichlorobenzoyl)benzenesulfonate monomer was prepared. Under N2 protection, 9.00 g (0.036 mol) of the synthesized 2,5-dichlorobenzophenone monomer was placed in a 100 mL two-necked flask, N2 was introduced, and 27 mL of fuming sulfuric acid with a SO3 content of 20% was added. The mixture was mechanically stirred. The oil bath temperature was set to 80 °C, and heating was stopped after 12 h. After being allowed to stand at room temperature, the solution was poured into 200 mL of ice-cold ultrapure water, and 5 M NaOH solution was added dropwise until the solution became weakly alkaline. The addition was then stopped. At this point, the solution released a large amount of heat, and a small amount of white precipitate formed. After standing at room temperature, a large amount of white solid precipitated. The solution was filtered to obtain a white solid crude product. The crude product was recrystallized twice with ultrapure water to obtain a white powder with a yield of 61%. Its chemical structure is as follows:

[0045]

[0046] Example 2

[0047] Preparation of [1,1'-biphenyl]-4-yl(2,5-dichlorophenyl) methyl ketone monomer: 20.95 g (0.10 mol) of 2,5-dichlorobenzoyl chloride prepared in Example 1, 23.13 g (0.15 mol) of biphenyl, and 14.67 g (0.11 mol) of anhydrous AlCl3 solid were placed in a 250 mL two-necked flask. 100 mL of CHCl3 was added as a solvent, and the mixture was magnetically stirred and N2 was introduced. The oil bath temperature was set to 70 °C, and the mixture was refluxed. The solution reacted vigorously and turned blackish-purple. Heating was continued at 70 °C for 5 hours, then heating was stopped, and the mixture was allowed to stand at room temperature before being removed. The reaction solution was poured into 200 mL (2M) of glacial hydrochloric acid aqueous solution to remove AlCl3. The organic phase obtained by separation was washed with 10% NaOH solution and deionized water until neutral. The CHCl3 solvent was removed by vacuum rotary evaporation to obtain a white solid. The crude solid product was recrystallized three times with petroleum ether to obtain pure [1,1'-biphenyl]-4-yl(2,5-dichlorophenyl) methyl ketone monomer in 90.2% yield. Its chemical structural formula is as follows:

[0048]

[0049] 4-(2,5-dichlorobenzoyl)-[1,1'-biphenyl]-2,4'-disulfonic acid sodium monomer was prepared. 9.00 g (0.028 mol) of the synthesized [1,1'-biphenyl]-4-yl(2,5-dichlorophenyl) methyl ketone monomer was placed in a 100 mL two-necked flask, N2 was introduced, and 27 mL of fuming sulfuric acid with a SO3 content of 20% was added. The mixture was mechanically stirred. The oil bath temperature was set to 80 °C, and heating was stopped after 12 h. After being placed at room temperature, the mixture was poured into 200 mL of ice water, and 5 M NaOH solution was added dropwise until the solution became weakly alkaline. The addition was then stopped. At this point, the solution released a large amount of heat, and a small amount of white precipitate formed. After being placed at room temperature, a large amount of white solid precipitated. The solution was filtered to obtain a white solid crude product. Recrystallization twice with ultrapure water yielded a white powder with a yield of 70%. Its chemical structure is as follows:

[0050]

[0051] Example 3

[0052] Preparation of polyaryl ketone precursor polymer 1 (x = 0.45, referring to the ratio of the molar number of sulfonated monomers / (molar number of sulfonated monomers + molar number of N-phenyl(4,4'-dichlorodiphenyl) ketone imine) at the time of feeding): 0.19 g (0.54 mmol) of sodium (2,5-dichlorobenzoyl)benzenesulfonate monomer, 0.22 g (0.67 mmol) of N-phenyl(4,4'-dichlorodiphenyl) ketone imine, and 2,2'-dichlorobenzoyl)benzenesulfonate... 1.13 g (7.26 mmol) of pyridine and 0.09 g (0.65 mmol) of anhydrous potassium carbonate were dried in a vacuum oven at 60 °C for 24 h, then added to a dry 25 mL two-necked flask. N2 was continuously purged through the flask for 1 h. 5 mL of anhydrous DMAC was then added to the flask as a solvent using a syringe. The temperature was raised to 80 °C, and 1.00 g (3.64 mmol) of bis(1,5-cyclooctadiene) nickel catalyst was added. The reaction was maintained at this temperature for 6 h. After the reaction was completed and cooled to room temperature, the resulting mixture was discharged into anhydrous ethanol. The product was washed five times with anhydrous ethanol and ultrapure water, respectively. Finally, it was vacuum dried at 60 °C to obtain the crude product of polyaryl ketone precursor polymer 1. The solid crude product was dissolved in 7 mL of NMP solvent, and insoluble impurities were removed by sintering. After drying at 80 °C, polyaryl ketone precursor polymer 1 was obtained with a yield of 80%. Its structural formula is as follows:

[0053]

[0054] Example 4

[0055] Preparation of polyaryl ketone precursor polymer 1 (x = 0.40): 0.17 g (0.48 mmol) of sodium (2,5-dichlorobenzoyl)benzenesulfonate monomer, 0.24 g (0.73 mmol) of N-phenyl(4,4'-dichlorodiphenyl) ketone imine, 1.13 g (7.26 mmol) of 2,2'-bipyridine, and 0.08 g (0.58 mmol) of anhydrous potassium carbonate were dried in a vacuum oven at 60 °C for 24 h. The mixture was then added to a dry 25 mL two-necked flask, and N2 was continuously purged for 1 h. 5 mL of anhydrous DMAC was then added to the flask as a solvent using a syringe. The temperature was raised to 80 °C, and 1.00 g (3.64 mmol) of bis(1,5-cyclooctadiene) nickel catalyst was added. The reaction was maintained at this temperature for 6 h. The polymer was treated in the same manner as in Example 3, with a yield of 81%. Its structural formula is as follows:

[0056]

[0057] Example 5

[0058] Preparation of polyaryl ketone precursor polymer 1 (x = 0.35): 0.15 g (0.42 mmol) of sodium (2,5-dichlorobenzoyl)benzenesulfonate monomer, 0.26 g (0.79 mmol) of N-phenyl(4,4'-dichlorodiphenyl) ketone imine, 1.13 g (7.26 mmol) of 2,2'-bipyridine, and 0.07 g (0.50 mmol) of anhydrous potassium carbonate were dried in a vacuum oven at 60 °C for 24 h. The mixture was then added to a dry 25 mL two-necked flask, and N2 was continuously purged for 1 h. 5 mL of anhydrous DMAC was then added to the flask as a solvent using a syringe. The temperature was raised to 80 °C, and 1.00 g (3.64 mmol) of bis(1,5-cyclooctadiene) nickel catalyst was added. The reaction was maintained at this temperature for 6 h. The polymer was treated in the same manner as in Example 3, with a yield of 83%. Its structural formula is as follows:

[0059]

[0060] Example 6

[0061] Preparation of polyaryl ketone precursor polymer 2 (x = 0.45): 0.29 g (0.54 mmol) of sodium 4-(2,5-dichlorobenzoyl)-[1,1'-biphenyl]-2,4'-disulfonate monomer, 0.22 g (0.67 mmol) of N-phenyl(4,4'-dichlorodiphenyl) ketone imine, 1.13 g (7.26 mmol) of 2,2'-bipyridine, and 0.09 g (0.65 mmol) of anhydrous potassium carbonate were dried in a vacuum oven at 60 °C for 24 h. The mixture was then added to a dry 25 mL two-necked flask, and N2 was continuously bubbled through it for 1 h. 5 mL of anhydrous DMAC was then added to the flask as a solvent using a syringe. The temperature was raised to 80 °C, and 1.00 g (3.64 mmol) of bis(1,5-cyclooctadiene) nickel catalyst was added. The reaction was maintained at this temperature for 6 h. After the reaction was completed and cooled to room temperature, the resulting mixture was discharged into anhydrous ethanol. The product was washed five times with anhydrous ethanol and ultrapure water, and finally dried under vacuum at 60°C to obtain the crude product of polyaryl ketone precursor polymer II. The solid crude product was dissolved in 7 mL of NMP solvent, and insoluble impurities were removed by sintering filter. After drying at 80°C, polyaryl ketone precursor polymer II was obtained with a yield of 79%. Its structural formula is as follows:

[0062]

[0063] Example 7

[0064] Preparation of polyaryl ketone precursor polymer 2 (x = 0.40): 0.25 g (0.48 mmol) of sodium 4-(2,5-dichlorobenzoyl)-[1,1'-biphenyl]-2,4'-disulfonate monomer, 0.19 g (0.24 mmol) of N-phenyl(4,4'-dichlorodiphenyl) ketone imine, 1.13 g (7.26 mmol) of 2,2'-bipyridine, and 0.08 g (0.58 mmol) of anhydrous potassium carbonate were dried in a vacuum oven at 60 °C for 24 h. The mixture was then added to a dry 25 mL two-necked flask, and N2 was continuously bubbled through it for 1 h. 5 mL of anhydrous DMAC was then added to the flask as a solvent using a syringe. The temperature was raised to 80 °C, and 1.00 g (3.64 mmol) of bis(1,5-cyclooctadiene) nickel catalyst was added. The reaction was maintained at this temperature for 6 h. The polymer was treated in the same manner as in Example 6 after the reaction, with a yield of 80%, and its structural formula is as follows:

[0065]

[0066] Example 8

[0067] Preparation of polyaryl ketone precursor polymer 2 (x = 0.35): 0.22 g (0.42 mmol) of sodium 4-(2,5-dichlorobenzoyl)-[1,1'-biphenyl]-2,4'-disulfonate monomer, 0.26 g (0.79 mmol) of N-phenyl(4,4'-dichlorodiphenyl) ketone imine, 1.13 g (7.26 mmol) of 2,2'-bipyridine, and 0.07 g (0.50 mmol) of anhydrous potassium carbonate were dried in a vacuum oven at 60 °C for 24 h. The mixture was then added to a dry 25 mL two-necked flask, and N2 was continuously bubbled through it for 1 h. 5 mL of anhydrous DMAC was then added to the flask as a solvent using a syringe. The temperature was raised to 80 °C, and 1.00 g (3.64 mmol) of bis(1,5-cyclooctadiene) nickel catalyst was added. The reaction was maintained at this temperature for 6 h. The polymer was treated in the same manner as in Example 6 after the reaction, with a yield of 82% and the following structural formula:

[0068]

[0069] Example 9

[0070] Preparation of polyaryl ketone polymer one: 0.2 g of each of the polyaryl ketone precursor polymers one prepared in Examples 3, 4 and 5 were placed in 20 mL of 1 M acid solution and soaked in an oven at 80 °C for 12 h. The filtered polymers were washed with ultrapure water until pH = 7 and dried in a vacuum oven at 80 °C for 12 h to obtain three polyaryl ketone polymers one with different proportions, with a yield of approximately 95%. Their structural formulas are as follows:

[0071]

[0072] Example 10

[0073] Preparation of polyaryl ketone polymer II: 0.2 g of each of the polyaryl ketone precursor polymer II prepared in Examples 6, 7, and 8 were placed in 20 mL of 1 M acid solution and soaked in an oven at 80°C for 12 h. The filtered polymers were washed with ultrapure water until pH = 7 and dried in a vacuum oven at 80°C for 12 h to obtain three polyaryl ketone polymer IIs with different proportions, with a yield of approximately 96%. Their structural formulas are as follows:

[0074]

[0075] Example 11

[0076] Preparation of homogeneous polyaryl ketone precursor membranes: 0.3 g each of polyaryl ketone precursor polymer I and polyaryl ketone precursor polymer II prepared in Examples 3-5 and 6-8 were dissolved in 7 mL of NMP solvent. After removing insoluble impurities by sintering, the solutions were cast onto 6×6 cm glass plates using a casting method and dried at 80 °C and 100 °C for 24 h, respectively. After natural cooling, two homogeneous polyaryl ketone precursor membranes with different ratios were obtained, with a membrane thickness of approximately 25 μm. The chemical structural formula of the homogeneous polyaryl ketone precursor membranes is as follows:

[0077]

[0078] A is independently selected

[0079] Example 12

[0080] Preparation of polyaryl ketone ion exchange membranes: Two homogeneous membranes of polyaryl ketone precursors prepared in Example 11 with different proportions were immersed in a 1M acid solution and hydrolyzed at 80°C for 12 hours. After washing with water until neutral, they were dried in a vacuum oven at 80°C to obtain polyaryl ketone ion exchange membrane one and polyaryl ketone ion exchange membrane two with different proportions. The thickness of the two prepared polyaryl ketone ion exchange membranes was approximately 30 μm. The chemical structural formula of the polyaryl ketone ion exchange membrane is as follows:

[0081]

[0082] A is independently selected

[0083] Example 13

[0084] To prepare 500 mL of Fenton's reagent at 2 ppm: Add 46.5 mL of 30% H2O2 to ultrapure water to make a 500 mL solution, then add 1 mg of anhydrous FeSO4 and stir well.

[0085] Different proportions of polyaryl ketone ion exchange membranes and SPEEK membranes with 60% sulfonation were cut into 1×1 cm pieces for oxidative stability testing. 1-35%, 1-40%, and 1-45% represent three different raw material proportions for polyaryl ketone ion exchange membrane one, i.e., x = 0.35, 0.40, and 0.45; 2-35%, 2-40%, and 2-45% represent three different raw material proportions for polyaryl ketone ion exchange membrane two, i.e., x = 0.35, 0.40, and 0.45. The membranes were then immersed in glass bottles containing 50 mL of 2 ppm Fenton's reagent and heated in an oven at 80°C. The mass retention rate (wt%) of the membrane after 1 hour of immersion was recorded. [The mass retention rate (wt%) is the ratio of the remaining mass (W2) of the membrane after 1 hour of oxidative stability testing to the mass (W1) of the membrane before testing.] The experiment was conducted in three parallel sets for each proportion of the membrane until the membrane was damaged, and the results are shown in Table 1.

[0086] Table 1: Mass retention rate (wt%) and time (t) until film breakage after 1 hour of immersion.

[0087] SPEEK 1-35％ 1-40％ 1-45％ 2-35％ 2-40％ 2-45％ t / h 1.0 65.0 60.5 53.0 60.0 52.0 45.0 wt% 80.1 99.4 98.9 98.5 99.1 98.5 98.1

[0088] The results in Table 1 show that, compared with SPEEK membranes, the polyaryl ketone ion exchange membranes prepared in this invention have excellent antioxidant stability.

[0089] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing an antioxidant non-fluorine ion exchange membrane, comprising the following steps: (1) Preparation of polyaryl ketone precursor polymers: N-phenyl(4,4'-dichlorodiphenyl) ketimide, sodium (2,5-dichlorobenzoyl)benzenesulfonate monomer or sodium 4-(2,5-dichlorobenzoyl)-[1,1'-biphenyl]-2,4'-disulfonate monomer, 2,2'-bipyridine and anhydrous potassium carbonate are added to a dry two-necked flask, and N2 is continuously introduced. For 0.5–2 h, add solvent to the flask using a syringe; after heating to 70–90 °C, add bis(1,5-cyclooctadiene)nickel as a catalyst, and maintain the temperature for 4–8 h; wherein the total molar ratio of N-phenyl(4,4'-dichlorodiphenyl)oneimine and sodium sulfonate monomers to the bis(1,5-cyclooctadiene)nickel catalyst is 1:1–4, and the amount of N-phenyl(4,4'-dichlorodiphenyl)oneimine monomer is not 0; the molar ratio of bis(1,5-cyclooctadiene)nickel catalyst to 2,2'-bipyridine is 1:1–3. The solvent mass is 2 to 10 times the total mass of the reactants. After the reaction is completed and cooled to room temperature, the resulting mixture is discharged into anhydrous ethanol. The product is washed 5 to 6 times with anhydrous ethanol and ultrapure water, respectively, and finally dried under vacuum at 50 to 70°C to obtain the crude polyaryl ketone precursor polymer. The crude product is then dissolved in 5 to 10 mL of NMP solvent, and insoluble impurities are removed by sintering. After drying at 70 to 100°C to remove the solvent, the polyaryl ketone precursor polymer is obtained with a yield of 60 to 80%. The structural formula of the product is shown below: A is independently selected (2) Take 0.2-0.5g of polyaryl ketone precursor polymer prepared in step (1), dissolve it in 5-10mL of solvent, completely dissolve it, filter it with a sand core, cast it onto a glass plate, and then dry it at 75-85℃ and 95-120℃ for 20-30h to remove the solvent, and obtain a homogeneous polyaryl ketone precursor membrane with a thickness of 10-60μm; (3) The homogeneous membrane of polyaryl ketone precursor prepared in step (2) is placed in 0.5-2.0M hydrochloric acid solution and soaked at 70-90℃ for 8-15h. Then it is washed with ultrapure water until the pH is 6.5-8.5, and then dried at 70-90℃ under vacuum for 10-15h to obtain polyaryl ketone ion exchange membrane, namely antioxidant non-fluorine ion exchange membrane, with a membrane thickness of 10-60μm.

2. The method for preparing an antioxidant non-fluorine ion exchange membrane as described in claim 1, characterized in that: The solvents in steps (1) and (2) are anhydrous N,N-dimethylacetamide, N,N'-dimethylformamide, N-methylpyrrolidone or dimethyl sulfoxide.

3. An antioxidant non-fluorine ion exchange membrane, characterized in that: It is prepared by the method described in claim 1 or 2.

4. The application of the antioxidant non-fluorine ion exchange membrane according to claim 3 in functional membranes.

5. A polyaromatic ketone polymer, the structure of which is shown below: A is selected independently x and y represent the molar proportions of each component in the polymer chain, x + y = 1, and 0 < x < 1.

6. The method for preparing a polyaryl ketone polymer according to claim 5, characterized in that: The polyaryl ketone precursor polymer prepared in step (1) of claim 1 was placed in an acid solution of 0.5-2.0 M and soaked at 70-100 °C for 8-15 h. After filtration, the polymer was washed with ultrapure water until the pH was 6.5-8.5 and then dried under vacuum at 70-90 °C to obtain the polyaryl ketone polymer.

7. The method for preparing a polyaryl ketone polymer as described in claim 6, characterized in that: The acid solution is either sulfuric acid or hydrochloric acid.

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