Ionization process for perfluorinated ion exchange resin and application of ionization process

Abstract

The invention belongs to the technical field of preparation methods of fluorine-containing high polymer materials, and particularly provides an ionization process for perfluorinated ion exchange resin and application of the perfluorinated ion exchange resin. The perfluorinated ion exchange resin at least contains one phosphate side group and one or more other ion exchange groups at the same time. A hydrolysis reaction is carried out in a hydrolysate composed of an alkaline catalyst and a polar organic solution, so that the problem that a CF2-P bond in a phosphate group is easy to break in an alkaline solution is solved, and hydrolysis of phosphate and other ion exchange groups under the same hydrolysis condition is realized.

Description

Technical Field

[0001] The invention relates to a method for preparing a fluorine-containing polymer material, and in particular to an ionization process of a perfluorinated ion exchange resin and an application thereof. Background Art

[0002] Perfluorosulfonic acid ion exchange resin is used in proton exchange membrane fuel cells due to its special properties. The operating temperature range of the fuel cell membrane electrode, which is currently widely used and uses perfluorosulfonic acid resin as the key raw material, is only between 25-80°C. The lower operating temperature range will cause the catalyst layer of the membrane electrode to be poisoned when the CO content reaches 10ppm. In order to solve the current difficulties in fuel cell membrane electrodes, an effective solution is to increase the operating temperature of fuel cells. Therefore, the development of high-temperature resistant proton exchange membranes has become a research focus at home and abroad. A series of research results have been achieved in response to the problem that fuel cells are difficult to operate stably above 100°C.

[0003] At present, the research is mainly focused on phosphoric acid-doped polymer proton membranes and their fuel cell systems. Although this type of membrane has a simple preparation process and strong high-temperature proton conductivity, phosphoric acid is easy to migrate and precipitate, resulting in a serious decline in the mechanical and chemical properties of the proton membrane, and it cannot meet the actual use of fuel cells. Due to the limitations of the proton conduction and physical and chemical properties of sulfonic acid and phosphoric acid groups, perfluorosulfonic acid proton membranes have difficulty conducting protons above 100°C, while phosphoric acid-doped membranes have difficulty conducting protons below 100°C. Therefore, the realization of polymers and membranes containing both phosphoric acid and sulfonic acid structures can greatly expand the operating temperature range of fuel cell membranes to above 120°C, breaking through the current bottleneck of low cross-temperature operation of fuel cells.

[0004] There are few studies on fluorinated polymers containing phosphoric acid-sulfonic acid structures, which are basically at the exploratory stage. The information that can be found at present is mainly binary polymers of perfluorophosphate and tetrafluoroethylene copolymers, and the related research is more on the polymerization method and the test application of resin structure. The article Yamabe, Masaaki et al. "Novel phosphonated perfluorocarbon polymers." European Polymer Journal 36 (2000): 1035-1041 introduces that when the perfluorophosphate polymer is treated with alkali solution, the CF2-P bond will be completely broken, and the phosphate polymer can be converted into phosphoric acid by acid hydrolysis. The commonly used hydrolysis method of perfluorosulfonyl fluoride resin is to use 5-50% alkali solution to treat it into sulfonate and then acidify it. The sulfonyl fluoride -SO2F group of perfluorosulfonyl fluoride resin is very stable in acid solution. To prepare fluorinated ion exchange resins containing both phosphate and sulfonyl fluoride, free radical polymerization of perfluorophosphate monomers and perfluorosulfonyl fluoride monomers is usually used. Only when the fluorinated ion exchange resin precursor containing phosphate and sulfonyl fluoride groups is hydrolyzed into phosphoric acid and sulfonic acid can it have ion or proton exchange function and be used in fuel cell membranes. However, since perfluorophosphate polymers decompose in alkaline solutions, it is difficult to ionize the fluorinated ion exchange resin precursor containing phosphate and sulfonyl fluoride groups. Summary of the invention

[0005] Aiming at the problem that ionization of fluorinated ion exchange resin containing phosphate ester in alkaline solution may lead to decomposition, the present invention proposes an ionization process for perfluoro ion exchange resin, which adopts alkaline substance and a solution containing polar organic solvent as hydrolyzing solution, and realizes hydrolysis of phosphate ester group in alkaline solution by adjusting the ionization process without destroying the CP bond in phosphate ester, and realizes hydrolysis of phosphate ester, sulfonyl fluoride and / or carboxylate ester group at the same time, thereby simplifying the process.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is:

[0007] An ionization process for a perfluorinated ion exchange resin, wherein the perfluorinated ion exchange resin is subjected to a hydrolysis reaction in a hydrolysis solution;

[0008] The hydrolysis solution includes an alkaline hydrolysis catalyst and a polar organic solution;

[0009] The perfluoro ion exchange resin is copolymerized by fluorine-containing olefin monomers, perfluoro phosphate monomers containing phosphate groups on the side chains, and monomers containing ion / proton exchange groups on the side chains.

[0010] The monomer containing an ion / proton exchange group on the side chain includes one or more of a perfluorosulfonyl fluoride monomer containing a sulfonyl fluoride group on the side chain and a perfluorocarboxylate monomer containing a carboxylic acid group on the side chain.

[0011] The fluorine-containing olefin monomer is selected from one or more of tetrafluoroethylene, hexafluoropropylene, vinyl fluoride, trifluoropropylene, chlorotrifluoroethylene, vinylidene fluoride, trifluorostyrene, and octafluorobutadiene.

[0012] Preferably, the perfluorophosphate monomer containing a phosphate group in the side chain is selected from one or more of formula (I) and formula (II):

[0013]

[0014] In formula (I), m is an integer of 0-12, preferably m=0-6, more preferably m=1-3;

[0015] n is an integer of 0-12, preferably n=0-6, more preferably n=1-3;

[0016] -R group is C x H 2x+1 , wherein x is an integer of 0-12, preferably x=0-6, more preferably x=0-3.

[0017] In formula (II), m is an integer of 0-6, preferably m=0-3, more preferably m=0-1;

[0018] -R group is C x H 2x+1 , wherein x is an integer of 0-12, preferably x=0-6, more preferably x=0-3.

[0019] Preferably, the perfluorosulfonyl fluoride monomer containing a sulfonyl fluoride group on the side chain is selected from monomers having the structural formula (III):

[0020]

[0021] In formula (III), m is an integer of 0-6, preferably m=0-3, more preferably m=0-1;

[0022] n is an integer of 0-12, preferably n=0-8, more preferably n=0-4.

[0023] Preferably, the perfluorocarboxylate monomer containing a carboxylate group in the side chain is selected from monomers of structural formula (IV):

[0024]

[0025] In formula (IV), m is an integer of 0-12, preferably m=0-6, more preferably m=1-3;

[0026] n is an integer of 0 to 12, preferably n=0 to 8, more preferably n=0 to 4;

[0027] -R group is C x H 2x+1 , wherein x is an integer of 0-12, preferably x=0-6, more preferably x=0-3.

[0028] Preferably, the alkaline hydrolysis catalyst is selected from one or more of sodium hydroxide, potassium hydroxide, lithium hydroxide, cesium hydroxide, rubidium hydroxide, ammonia water, triethylamine, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, lithium carbonate, lithium bicarbonate, and ammonium carbonate.

[0029] Preferably, the polar organic solvent is one or more mixtures of methanol, ethanol, ethylene glycol, n-propanol, isopropanol, n-butanol, acetone, glycerol, butylene glycol, propylene glycol, N-methylpyrrolidone (NMP), N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and N,N-dimethylacetamide (DMAc).

[0030] Preferably, the ionization process for perfluorinated ion exchange resin comprises the following steps:

[0031] (1) adding a perfluoro ion exchange resin to a hydrolyzate to obtain a resin-hydrolyzate mixture;

[0032] (2) heating and stirring the resin-hydrolyzate mixture to perform a hydrolysis reaction;

[0033] (3) After cooling the product obtained in step (2) to room temperature, removing impurities and acidifying to obtain a perfluoro ion exchange resin containing phosphoric acid, sulfonic acid and / or carboxylic acid.

[0034] Preferably, the molar ratio of the alkaline hydrolysis catalyst to the ion exchange groups in the perfluoro ion exchange resin is (2-10): 1. Too high a content of the alkaline hydrolysis catalyst will result in the cleavage of the CP bond.

[0035] Preferably, the perfluoro ion exchange resin is 0.5-50% of the total mass of the polar organic solution and the perfluorosulfonic acid exchange resin, preferably 0.5-30%.

[0036] Preferably, the mass percentage of the polar organic solvent in the polar organic solution is 30-100%. Preferably, the hydrolysis temperature is 60-280° C., and the hydrolysis time is 1-96 hours.

[0037] The normal temperature in the present invention is 10-30°C.

[0038] The acidification method is acidification with acid solution or exchange with hydrogen-type ion exchange resin;

[0039] The acid solution is a strong acid or a mixture of strong acids;

[0040] Preferably, the strong acid includes nitric acid, sulfuric acid, and nitric acid.

[0041] The present invention also provides the application of the above-mentioned ionization process, and the application fields include the preparation of proton exchange membrane fuel cell electrodes and electrolyte membranes, especially high-temperature resistant proton battery membranes, vanadium liquid flow battery membranes, production and repair of ion membranes; hydrophilic treatment of polytetrafluoroethylene surface, catalyst coating, electrochemical sensor production; electrolysis devices, electrochemical devices, and electrodialysis devices.

[0042] The invention hydrolyzes in a hydrolysis solution composed of an alkaline hydrolysis catalyst and a polar organic solution, and hydrolyzes a perfluoro ion exchange resin containing phosphoric acid ester, sulfonyl fluoride and / or carboxylic acid ester simultaneously under a certain solid content, temperature and constant temperature time, hydrolyzes the sulfonyl fluoride into sulfonate, hydrolyzes the carboxylate into carboxylic acid, and hydrolyzes the phosphoric acid ester into phosphate or phosphoric acid, and then acidifies or hydrogen-type ion exchanges the hydrolyzed and dissolved resin to obtain a perfluoro ion exchange resin containing phosphoric acid, sulfonic acid and / or carboxylic acid ester simultaneously.

[0043] Beneficial Effects

[0044] 1. The present invention is hydrolyzed in a hydrolysis solution composed of an alkaline hydrolysis catalyst and a polar organic solution, wherein the alkaline hydrolysis catalyst is used to hydrolyze the sulfonyl fluoride group / carboxylate group, and the polar organic solution is used to hydrolyze the phosphate group, so as to achieve simultaneous hydrolysis of the perfluoro ion exchange resin containing phosphate, sulfonyl fluoride and / or carboxylate.

[0045] 2. In the prior art, the hydrolysis of sulfonyl fluoride / carboxylate groups is generally carried out under high concentration of alkaline solution. When the concentration is reduced, the hydrolysis reaction of the sulfonyl fluoride / carboxylate groups will slow down. The present invention adopts a polar organic solution, which can promote the rapid hydrolysis of sulfonyl fluoride / carboxylate while achieving the hydrolysis of phosphate. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 is the standard NMR phosphorus spectrum of the phosphate monomer in Example 1;

[0047] Figure 2 is the NMR fluorine spectrum of the perfluoro ion exchange resin containing phosphate and sulfonyl fluoride groups before hydrolysis in Example 1;

[0048] Figure 3 is the nuclear magnetic phosphorus spectrum of the perfluoro ion exchange resin containing phosphoric acid and sulfonic acid groups after hydrolysis in Example 1;

[0049] Figure 4The nuclear magnetic fluorine spectrum of the perfluorinated ion exchange resin containing phosphoric acid and sulfonic acid groups after hydrolysis in Example 1;

[0050] Figure 5 is the nuclear magnetic phosphorus spectrum of the perfluoro ion exchange resin after hydrolysis in Comparative Example 1;

[0051] Figure 6 This is the nuclear magnetic phosphorus spectrum of the perfluoro ion exchange resin after hydrolysis in Comparative Example 2. DETAILED DESCRIPTION

[0052] The present invention is described in more detail below by way of examples, but the present invention is not limited to the examples.

[0053] The perfluorinated ion exchange resins in the following examples can be prepared according to the techniques known in the art, and the preparation methods can be emulsion polymerization, solution polymerization, bulk polymerization and the like.

[0054] Example 1

[0055] (1) 350 g of EW885 perfluoro ion exchange resin containing phosphate and sulfonyl fluoride groups was added to a 5 L high temperature and high pressure reactor, and then 3150 g of a mixed solution of water and methanol in a mass ratio of 30:70 and 49.80 g of lithium hydroxide were added to the 5 L high temperature and high pressure reactor and stirred for 10 min until the lithium hydroxide was completely dissolved.

[0056] The perfluoro ion exchange resin is copolymerized by a fluorine-containing olefin monomer, a perfluorophosphate monomer containing a phosphate group on the side chain, and a perfluorosulfonyl fluoride monomer containing a sulfonyl fluoride group on the side chain.

[0057] The fluorine-containing olefin monomer is tetrafluoroethylene; the structural formula of the perfluorophosphate monomer containing a phosphate group in the side chain is:

[0058]

[0059] In formula (I), m is 0, n is 2, and the -R group is C2H5;

[0060] The structural formula of the perfluorosulfonyl fluoride monomer containing a sulfonyl fluoride group in the side chain is:

[0061]

[0062] In formula (III), m is 1 and n is 2.

[0063] (2) After sealing the high-pressure and high-temperature reactor, stir at 25°C for 30 min, then heat the reactor to 200°C, maintain stirring at 200°C for 6 h, and rotate at 200 rpm;

[0064] (3) Subsequently, the reactor was cooled to 25° C., and the solution in the reactor was filtered through a PTFE membrane with a pore size of 1 μm;

[0065] (4) The filtered solution is subjected to ion exchange in a glass exchange column containing a hydrogen-type cation exchange resin to obtain an ion exchange resin containing both phosphoric acid and sulfonic acid.

[0066] like Figure 1 The standard NMR phosphorus spectrum of the phosphate monomer is shown in Figure 1. It can be seen from the figure that the three signal peaks of phosphorus are at -0.28ppm, -0.7ppm, and -1.0ppm. Figure 3 In the NMR phosphorus spectrum of the hydrolyzed perfluoro ion exchange resin containing phosphate and sulfonyl fluoride groups, after hydrolysis, the three phosphorus signal peaks (-0.28ppm, -0.7ppm, -1.0ppm) near 0-1ppm are very strong, indicating that the hydrolysis method of this embodiment does not destroy the CP bond of the perfluoro ion exchange resin.

[0067] The NMR spectra of the perfluorinated ion exchange resin containing phosphate and sulfonyl fluoride groups before and after hydrolysis are as follows: Figure 2 , 4 As shown in the figure, it can be seen that the nuclear magnetic resonance fluorine spectrum of the perfluorinated ion exchange resin before and after hydrolysis has basically no change.

[0068] Example 2

[0069] (1) 175 g of EW400 fluorinated ion exchange resin containing phosphate and carboxylate groups was added to a 5 L high temperature and high pressure reactor, and then 3325 g of pure ethanol and 80.9 g of lithium carbonate were added to the 5 L high temperature and high pressure reactor and stirred for 30 min until the lithium carbonate was completely dissolved.

[0070] The perfluoro ion exchange resin is copolymerized by a fluorine-containing olefin monomer, a perfluorophosphate monomer containing a phosphate group on the side chain, and a perfluorosulfonyl fluoride monomer containing a sulfonyl fluoride group on the side chain.

[0071] The fluorine-containing olefin monomer is tetrafluoroethylene; the structural formula of the perfluorophosphate monomer containing a phosphate group in the side chain is:

[0072]

[0073] In formula (I), m is 1; n is 2; the -R group is C2H5;

[0074] The structural formula of the perfluorosulfonyl fluoride monomer containing a sulfonyl fluoride group in the side chain is:

[0075]

[0076] In formula (III), m is 1 and n is 2.

[0077] (2) After sealing the high-pressure and high-temperature reactor, stir at 25°C for 30 min, then heat the reactor to 150°C, maintain stirring at 150°C for 20 h, and rotate at 250 rpm;

[0078] (3) After the reactor is cooled to 25°C, the solution in the reactor is filtered through a PP membrane with a pore size of 2 μm;

[0079] (4) The filtered solution is exchanged in a chromatography column containing a hydrogen-type cation exchange resin to obtain an ion exchange resin containing both phosphoric acid and carboxylic acid.

[0080] Example 3

[0081] (1) 525 g of EW750 fluorinated ion exchange resin containing phosphate and sulfonyl fluoride groups was added to a 2 L high temperature and high pressure reactor, and then 2975 g of a mixed solution of water and n-propanol in a mass ratio of 50:50 and 78.4 g of sodium hydroxide were added to the 2 L high temperature and high pressure reactor and stirred for 10 min until the sodium hydroxide was completely dissolved.

[0082] The perfluoro ion exchange resin is copolymerized by a fluorine-containing olefin monomer, a perfluorophosphate monomer containing a phosphate group on the side chain, and a perfluorosulfonyl fluoride monomer containing a sulfonyl fluoride group on the side chain.

[0083] The fluorine-containing olefin monomer is tetrafluoroethylene; the structural formula of the perfluorophosphate monomer containing a phosphate group in the side chain is:

[0084]

[0085] In formula (I), m is 0; n is 2; the -R group is C2H5;

[0086] The structural formula of the perfluorosulfonyl fluoride monomer containing a sulfonyl fluoride group in the side chain is:

[0087]

[0088] In formula (III), m is 0 and n is 4. (2) After sealing the high-pressure and high-temperature reactor, stir at 25°C for 30 minutes, then heat the reactor to 230°C, and maintain the temperature at 230°C for 10 hours at a rotation speed of 350 rpm.

[0089] (3) After the constant temperature timing is completed, the reactor is cooled to 25° C. and the reactor is opened. The solution in the reactor is centrifuged at 5000 rpm to separate the insoluble matter;

[0090] (4) The supernatant after centrifugation is exchanged in a chromatography column containing a hydrogen-type cation exchange resin to obtain an ion exchange resin containing both phosphoric acid and sulfonic acid.

[0091] Example 4

[0092] (1) 87.5 g of EW1000 fluorinated ion exchange resin containing phosphate and sulfonyl fluoride groups was added to a 5 L high temperature and high pressure reactor, and then 3412.5 g of a mixed solution of water and n-propanol in a mass ratio of 40:60 and 29.4 g of potassium hydroxide were added to the 5 L high temperature and high pressure reactor and stirred for 10 min until the potassium hydroxide was completely dissolved.

[0093] The perfluoro ion exchange resin is copolymerized by a fluorine-containing olefin monomer, a perfluorophosphate monomer containing a phosphate group on the side chain, and a perfluorosulfonyl fluoride monomer containing a sulfonyl fluoride group on the side chain.

[0094] The fluorine-containing olefin monomer is tetrafluoroethylene; the structural formula of the perfluorophosphate monomer containing a phosphate group in the side chain is:

[0095]

[0096] In formula (I), m is 2; the -R group is CH3;

[0097] The structural formula of the perfluorosulfonyl fluoride monomer containing a sulfonyl fluoride group in the side chain is:

[0098]

[0099] In formula (III), m is 0 and n is 2.

[0100] (2) After sealing the high-pressure and high-temperature reactor, stir at 25°C for 30 min, then heat the reactor to 80°C and maintain the temperature at 80°C for 24 h at a rotation speed of 350 rpm.

[0101] (3) After the constant temperature timing is completed, the reactor is cooled to 25°C and the inside of the reactor is opened. The solution in the reactor is centrifuged at 5000 rpm to separate the insoluble matter in the lower layer;

[0102] (4) adding 20 wt % nitric acid solution to the supernatant after centrifugation and then ultrafiltration and concentration, and after five cycles, the potassium ion content in the solution is less than 10 ppm, and the acidification is completed to obtain an ion exchange resin containing both phosphoric acid and sulfonic acid.

[0103] Example 5

[0104] (1) 175 g of EW800 fluorinated ion exchange resin containing phosphate and carboxylate groups was added to a 5 L high temperature and high pressure reactor, and then 3325 g of dimethyl sulfoxide (DMSO) and water in a mass ratio of 50:50 and 27.6 g of lithium hydroxide were added to the 5 L high temperature and high pressure reactor and stirred for 30 min until the lithium hydroxide was completely dissolved.

[0105] The perfluoro ion exchange resin is copolymerized by a fluorine-containing olefin monomer, a perfluorophosphate monomer containing a phosphate group on the side chain, and a perfluorocarboxylate monomer containing a carboxylate group on the side chain.

[0106] The fluorine-containing olefin monomer is tetrafluoroethylene; the structural formula of the perfluorophosphate monomer containing a phosphate group in the side chain is:

[0107]

[0108] In formula (I), m is 0; n is 2; the -R group is CH3;

[0109] The structural formula of the perfluorocarboxylate monomer containing a carboxylate group in the side chain is:

[0110]

[0111] In formula (IV), m is 1; n is 2; -R group is CH3. (2) After sealing the high-pressure and high-temperature reactor, stir at 25°C for 30 minutes, then heat the reactor to 150°C, and maintain the temperature at 150°C for 10 hours at a rotation speed of 250 rpm;

[0112] (3) After the thermostatic timing is completed, the reactor is cooled to 25° C. and then the reactor is opened. The solution in the reactor is filtered through a 2 μm PP membrane filter to obtain a perfluoro ion exchange resin solution containing both phosphoric acid and carboxylic acid.

[0113] (4) The 2 μm PP membrane filter solution is exchanged in a chromatography column containing a hydrogen-type cation exchange resin to obtain an ion exchange resin containing both phosphoric acid and carboxylic acid.

[0114] Example 6

[0115] (1) 105 g of EW950 fluorinated ion exchange resin containing phosphate and sulfonyl fluoride groups was added to a 5 L high temperature and high pressure reactor, and then 3325 g of acetone and water in a mass ratio of 80:20 and 51.6 g of 30 wt % ammonia water were added to the 5 L high temperature and high pressure reactor.

[0116] The perfluoro ion exchange resin is copolymerized by a fluorine-containing olefin monomer, a perfluorophosphate monomer containing a phosphate group on the side chain, and a perfluorosulfonyl fluoride monomer containing a sulfonyl fluoride group on the side chain.

[0117] The fluorine-containing olefin monomer is tetrafluoroethylene; the structural formula of the perfluorophosphate monomer containing a phosphate group in the side chain is:

[0118]

[0119] In formula (I), m is 2; the -R group is C2H5;

[0120] The structural formula of the perfluorosulfonyl fluoride monomer containing a sulfonyl fluoride group in the side chain is:

[0121]

[0122] In formula (III), m is 0 and n is 2.

[0123] (2) After sealing the high-pressure and high-temperature reactor, stir at 25°C for 30 min, then heat the reactor to an internal temperature of 260°C and maintain the temperature at 260°C for 8 h at a rotation speed of 200 rpm.

[0124] (3) After the constant temperature timing is completed, the reactor is cooled to 25°C and then the reactor is opened, and the solution in the reactor is filtered through a 2-micron PP membrane;

[0125] (4) The filtered fluorine-containing ion exchange resin is replaced 10 times in a 10 wt % sulfuric acid solution at 65° C., and the acidification is completed when the lithium ion content in the resin is less than 15 ppm, thereby obtaining a fluorine-containing ion exchange resin containing phosphoric acid and sulfonic acid.

[0126] Example 7

[0127] (1) 105 g of EW1050 fluorinated ion exchange resin containing phosphate, carboxylate and sulfonyl fluoride groups was added to a 5 L high temperature and high pressure reactor, and then 3325 g of methanol and water with a mass ratio of 70:30 and 51.6 g of 30% ammonia water were added to the 5 L high temperature and high pressure reactor.

[0128] The perfluoro ion exchange resin is copolymerized by fluorine-containing olefin monomers, perfluorophosphate monomers containing phosphate groups on the side chains, perfluorosulfonyl fluoride monomers containing sulfonyl fluoride groups on the side chains, and perfluorocarboxylate monomers containing carboxylate groups on the side chains.

[0129] The fluorine-containing olefin monomer is tetrafluoroethylene; the structural formula of the perfluorophosphate monomer containing a phosphate group in the side chain is:

[0130]

[0131] In formula (I), m is 0; n is 2; the -R group is C2H5;

[0132] The structural formula of the perfluorosulfonyl fluoride monomer containing a sulfonyl fluoride group in the side chain is:

[0133]

[0134] In formula (III), m is 0; n is 4;

[0135] The structural formula of the perfluorocarboxylate monomer containing a carboxylate group in the side chain is:

[0136]

[0137] In formula (IV), m is 1; n is 2; and the -R group is CH3.

[0138] (2) After sealing the high-pressure and high-temperature reactor, stir at 25°C for 30 min, then heat the reactor to an internal temperature of 260°C and maintain the temperature at 260°C for 8 h at a rotation speed of 200 rpm.

[0139] (3) After the constant temperature timing is completed, the reactor is cooled to 25°C and then the reactor is opened, and the solution in the reactor is filtered through a 2-micron PP membrane;

[0140] (4) The filtered fluorine-containing ion exchange resin is replaced 10 times in a 10 wt % sulfuric acid solution at 65° C., and the acidification is completed when the lithium ion content in the resin is less than 15 ppm, thereby obtaining a fluorine-containing ion exchange resin containing phosphoric acid and sulfonic acid.

[0141] Comparative Example 1

[0142] The hydrolyzate used in this comparative example is a 20 wt % KOH aqueous solution containing 5 wt % methanol. The hydrolysis temperature is 85° C. and the sample is tested for nuclear magnetic phosphorus spectrum after 72 hours. Figure 5 As shown, 12 wt % hydrochloric acid is used for acidification, deionized water is used for washing, and the resin is dried to obtain a perfluoro ion exchange resin. The remaining steps are the same as those in Example 1.

[0143] from Figure 5 It can be seen that when the perfluoro ion exchange resin solution with the same concentration is tested for the nuclear magnetic phosphorus spectrum, the phosphorus signal peak near 0ppm is much weakened, indicating that more CP bonds are broken. This is because: in order to quickly hydrolyze the sulfonyl fluoride group and increase the solubility of the alkali solution, the CP bond is broken. In this comparative example, since the methanol content is too low, the CP bond cannot be effectively protected, resulting in more CP bonds being broken.

[0144] Comparative Example 2

[0145] The hydrolyzate used in this comparative example is a 20 wt % LiOH aqueous solution. After the hydrolysis temperature is 200°C for 6 hours, the sample is tested for nuclear magnetic phosphorus spectrum. Figure 6 As shown, 10 wt % nitric acid is used for acidification, deionized water is used for washing, and the resin is dried to obtain a perfluoro ion exchange resin. The remaining steps are the same as those in Example 1.

[0146] from Figure 6It can be seen that when the perfluoro ion exchange resin solution with the same concentration is tested for NMR phosphorus spectrum, the phosphorus signal peak near 0 ppm disappears, indicating that the CP bond in the resin has been completely broken. This is because: in order to hydrolyze the sulfonyl fluoride group, the lithium hydroxide content in this comparative example is too high, which promotes the breakage of CP.

[0147] As shown in Table 1, the ion exchange capacity of each embodiment and the comparative example is tested using GB / T30296 2013. As shown in Table 1, the ion exchange capacity of each embodiment and the comparative example before and after ionization treatment is shown. It can be seen from the table that the ion exchange capacity of the present invention is slightly reduced, while the exchange capacity of the comparative example is significantly reduced by the ionization method, but there is still about 0.45 mmol / g of exchange capacity mainly derived from the sulfonic acid group, and the phosphate group in the comparative example is basically completely decomposed.

[0148] Table 1 Ion exchange capacity of Examples 1-7 and Comparative Examples 1-2

[0149]

Claims

1. An ionization process for perfluorinated ion exchange resin, characterized in that: The perfluorinated ion exchange resin undergoes a hydrolysis reaction in the hydrolyzate; The hydrolysis solution includes an alkaline hydrolysis catalyst and a polar organic solution; The perfluoro ion exchange resin is copolymerized by a fluorinated olefin monomer, a perfluorophosphate monomer having a phosphate group on the side chain, and a monomer having an ion / proton exchange group on the side chain; The monomer containing an ion / proton exchange group on the side chain includes one or more of a perfluorosulfonyl fluoride monomer containing a sulfonyl fluoride group on the side chain and a perfluorocarboxylate monomer containing a carboxylic acid group on the side chain; The polar organic solution is an aqueous solution of a polar organic solvent.

2. The ionization process for perfluorinated ion exchange resin according to claim 1, characterized in that: The polar organic solvent is one or a mixture of methanol, ethanol, ethylene glycol, n-propanol, isopropanol, n-butanol, acetone, glycerol, butylene glycol, propylene glycol, N-methylpyrrolidone, N,N-dimethylformamide, dimethyl sulfoxide, N,N-dimethylacetamide; Preferably, the mass percentage of the polar organic solvent in the polar organic solution is 30-100%.

3. The ionization process for perfluorinated ion exchange resin according to claim 1, characterized in that: The alkaline hydrolysis catalyst is selected from one or more of sodium hydroxide, potassium hydroxide, lithium hydroxide, cesium hydroxide, rubidium hydroxide, ammonia water, triethylamine, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, lithium carbonate, lithium bicarbonate, and ammonium carbonate; Preferably, the molar ratio of the alkaline hydrolysis catalyst to the ion exchange groups in the perfluoro ion exchange resin is (2-10):

1.

4. The ionization process for perfluorinated ion exchange resin according to claim 1, characterized in that: The hydrolysis temperature is 60-280° C., and the hydrolysis time is 1-96 hours.

5. The ionization process for perfluorinated ion exchange resin according to claim 1, characterized in that: The structural formula of the perfluorophosphate monomer containing a phosphate group in the side chain is selected from one or more of formula (I) and formula (II): In formula (I), m is an integer of 0-12, preferably m=0-6, more preferably m=1-3, n is an integer of 0-12, preferably n=0-6, more preferably n=1-3, -R group is C x H 2x+1 , wherein x is an integer of 0-12, preferably x=0-6, more preferably x=0-3; In formula (II), m is an integer of 0-6, preferably m=0-3, more preferably m=0-1, -R group is C x H 2x+1 , wherein x is an integer of 0-12, preferably x=0-6, more preferably x=0-3.

6. The ionization process for perfluorinated ion exchange resin according to claim 1, characterized in that: The structural formula of the perfluorosulfonyl fluoride monomer containing a sulfonyl fluoride group in the side chain is selected from formula (III): In formula (III), m is an integer of 0-6, preferably m=0-3, more preferably m=0-1; n is an integer of 0-12, preferably n=0-8, more preferably n=0-4.

7. The ionization process for perfluorinated ion exchange resin according to claim 1, characterized in that: The structural formula of the perfluorocarboxylate monomer containing a carboxylate group in the side chain is selected from formula (IV): In formula (IV), m is an integer of 0-12, preferably m=0-6, more preferably m=1-3; n is an integer of 0 to 12, preferably n=0-8, more preferably n=0-4; -R group is C x H 2x+1 , wherein x is an integer of 0-12, preferably x=0-6, more preferably x=0-3.

8. The ionization process for perfluorinated ion exchange resin according to claim 1, characterized in that: The perfluorinated ion exchange resin accounts for 0.5-50% of the total mass of the polar organic solution and the perfluorinated ion exchange resin, preferably 0.5-30%.

9. The ionization process for perfluorinated ion exchange resin according to claim 1, characterized in that: (1) adding a perfluoro ion exchange resin to a hydrolyzate to obtain a resin-hydrolyzate mixture; (2) heating and stirring the resin-hydrolyzate mixture to perform a hydrolysis reaction; (3) After cooling the product obtained in step (2) to room temperature, removing impurities and acidifying to obtain a perfluoro ion exchange resin containing phosphoric acid, sulfonic acid and / or carboxylic acid.

10. An application of the ionization process according to claim 1, characterized in that: The application fields include: proton exchange membrane fuel cell electrodes, electrolyte membranes, polytetrafluoroethylene surface hydrophilic treatment, catalyst coating, electrochemical sensor production, electrolysis devices, electrochemical devices, and electrodialysis devices.

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