A Novel Class of Proton Exchange Membrane Materials Containing Phosphate Groups and Their Applications

Abstract

A novel class of phosphonate-containing proton exchange membrane materials and their applications belong to the field of functional organic polymer materials. These materials have a rigid structure with a three-dimensional large-volume steric hindrance, where the spiro[fluorene-9,9'-xanthene] serves as the core and the two rings form two perpendicular non-conjugated units. A series of derivatives synthesized from them have relatively high melting points and glass transition temperatures, can inhibit molecular crystallization, have good film-forming properties, contain abundant phosphoric acid groups, and are expected to be applied in, but not limited to, fields such as proton exchange membranes and catalysis.

Description

Technical Field

[0001] The present invention belongs to the field of functional organic polymer materials, and particularly relates to a novel class of proton exchange membrane materials containing phosphoric acid groups and their applications. Background Art

[0002] The role of the proton exchange membrane (PEM) is to isolate the gases on both sides while conducting protons (H + +). A high-performance proton exchange membrane can transfer H+ more quickly and in greater quantity, enabling the fuel cell to provide a higher-power output current. The membrane materials used in low-temperature proton exchange membrane fuel cells mainly include perfluorosulfonic acid type, partially fluorinated type, and non-fluorinated type proton exchange membranes.

[0003] The ionic conductivities of all the above polymers strongly depend on the presence of water, which limits their operating temperature to below 100 °C. It has been proven that compared with low-temperature operation, an increase in temperature offers many advantages, such as improved CO tolerance of the Pt electrode, higher energy efficiency, and simplified thermal management. Among these materials, the most studied are polybenzimidazole (PBI) and its blends doped with phosphoric acid and many modifications of their chemical structures, because of their excellent thermal stability and high proton conductivity. Another promising approach is to use aromatic polyethers because of their thermal and mechanical properties and their low cost. The introduction of polar groups provides interaction sites with phosphoric acid, resulting in the desired ionic conductivity.

[0004] However, the main drawback of these systems is that the water formed during battery operation can leach out the acid from the membrane, causing problems with its operating stability. A promising approach to overcome this problem is to covalently fix the acid units to a suitable polymer matrix. From this perspective, polyelectrolytes containing phosphonic acid units have attracted extensive interest because these materials have high thermal and oxidative stability, high proton conductivity at high temperatures, and low hydration conditions, as well as reduced water absorption, thus preventing membrane swelling. Although phosphated polymers are promising candidates for high-temperature polymer fuel cells, there is currently little research on this type of polymer. This is mainly due to the difficulty in preparing polymers with a high degree of phosphonation required for high ionic conductivity. One synthetic method is to polymerize suitable monomers functionalized with phosphonic acid sites, but according to the published attempts, most of these efforts have led to oligomeric products.

[0005] Spiroaromatic compounds have become important structural units of organic polymer materials due to their large conjugated systems, unique spiroconjugation effects, rigid coplanar structures, high glass transition temperatures, and good thermal stabilities. In spiroaromatic materials, spiro[fluorene-9,9'-xanthene] connects the fluorene ring and the xanthene ring through a centrally sp3-hybridized C atom, and different organic groups can be used to modify and modify it at different sites. Such an electron-rich spiro ring combination structure can effectively construct a non-planar three-dimensional molecular conformation in the molecular field. The steric hindrance effect can effectively inhibit the π-π interaction between molecules, thereby improving the solubility and stability of the material. At the same time, the large steric hindrance of the phosphonic acid group on the polymerization can be reduced. Therefore, it is very promising to study the application of such materials in the field of proton exchange membranes. Summary of the Invention

[0006] The present invention studies proton exchange membrane monomers containing phosphoric acid groups and their applications, and develops a class of dialdehydes, dicarboxylic acids, dinitriles, bis(tetrazoles), and bis(acyl chlorides) monomers containing multiple phosphonic acid groups. These monomers can polymerize with different types of monomers containing dinitriles, biphenyl diamines, acyl chlorides, etc. to form novel proton exchange membranes containing phosphonic acid groups, which are expected to be applied in the field of high-temperature proton exchange membranes.

[0007] The present invention first provides a compound of formula I:

[0008]

[0009] Wherein, each X is independently selected from

[0010] R1 is R2 is Or Each Y is independently an alkyl group having 1 to 3 carbon atoms.

[0011] In some specific compounds, X is

[0012] The present invention also provides a novel proton exchange membrane material containing a phosphoric acid group, and the material has a structure of formula II or formula III:

[0013]

[0014] Wherein, R3 is R4 is Or n is an integer.

[0015] Each Z is independently selected from

[0016] Specifically, the novel phosphonic acid-containing proton exchange membrane materials of this type can be selected from the following structures:

[0017]

[0018] By introducing phosphoric acid groups and active groups available for polymerization, the compounds of General Formula I can be used to prepare a series of proton exchange membrane materials containing abundant phosphoric acid groups through polymerization reactions.

[0019] For the compounds of General Formula I, with spiro[fluorene-9,9'-xanthene] as the core, the two rings form two perpendicular non-conjugated units, endowing it with a rigid structure with three-dimensional large steric hindrance. Therefore, a series of derivatives synthesized from it have relatively high melting points and glass transition temperatures, can inhibit the crystallization of molecules, have good film-forming properties, and improve the thermodynamic stability of molecules. Phosphonate can be coupled on the xanthene ring, and through the perpendicular structure of the spiro ring in space, the steric hindrance effect of the phosphonate group can be effectively reduced; the 2,7-positions of the fluorene ring have good reactivity and are excellent modification sites for polymerization linking groups, facilitating the extension of its structure into three-dimensional space. This type of phosphoric acid-containing proton exchange membrane monomer is polymerized with different commercially available polymer precursors to obtain a series of proton exchange membrane materials containing phosphonates, which are expected to be applied but not limited to fields such as proton exchange membranes and catalysis.

[0020] For the preparation method of the monomer compound described above, the method includes constructing spiro[fluorene-9,9'-xanthene] using fluorenone as the raw material, modifying the phosphonate on the xanthene ring by bromination and subsequent coupling, and forming different polymerization linking groups through coupling of the dibromo groups at the 2,7-positions of the fluorene ring for polymerization. Specifically, it includes the following steps:

[0021] Compound B obtained by the one-step bromination reaction of Compound A:

[0022]

[0023] Compound C is constructed by the spirocyclic ring-closing reaction of Compound B with butyllithium to obtain different spirocyclic structures:

[0024]

[0025] Compound D with a polymer linking group is obtained by various coupling reactions of Compound C and Compound V:

[0026]

[0027] Among them, X is defined as in the structural General Formula I, and Compound V is selected from carbon monoxide, carbon dioxide, potassium ferrocyanide trihydrate, etc.:

[0028] Compound E and Compound F are formed by the reaction of Compound D with bromine:

[0029]

[0030] Among them, X is specifically one of an aldehyde group, a carboxyl group, a methyl carboxylate group, and a cyano group.

[0031] Compound E, F and triethyl phosphite are coupled under the catalysis of nickel bromide to obtain monomeric structures P (P1 - P3), Q (Q1 - Q3) with phosphonates:

[0032]

[0033] Among them, X of P1 - P3 is specifically one of an aldehyde group, a methyl carboxylate group, and a cyano group. R1 is R2 is -H; Y is independently selected from methyl, ethyl, isopropyl, etc. X of Q1 - Q3 is specifically one of an aldehyde group, a methyl carboxylate group, and a cyano group. R1 is R2 is Y is independently selected from methyl, ethyl, isopropyl, etc.

[0034] P (P4 - P5), Q (Q4 - Q5) can be obtained by a one-step reaction of a monomer with a cyano group and a methyl carboxylate and compound W:

[0035]

[0036] Among them, X of P5 - P7, Q5 - Q7 is specifically one of a tetrazole group and an acyl chloride group. R1 is R2 is -H; Y is independently selected from methyl, ethyl, isopropyl, etc. X of Q1 - Q3 is specifically one of an aldehyde group, a methyl carboxylate group, and a cyano group. R1 is R2 is Y is independently selected from methyl, ethyl, isopropyl, etc.

[0037] Advantages of the present invention: A novel class of phosphonate-containing proton exchange membrane materials and their applications. These materials have a rigid structure with a three-dimensional large-volume steric hindrance, where spiro[fluorene-9,9'-xanthene] is used as the core and the two rings form two perpendicular non-conjugated units. A series of derivatives synthesized therefrom have relatively high melting points and glass transition temperatures, can inhibit the crystallization of molecules, have good film-forming properties, and improve the thermodynamic stability of molecules. The monomer materials can be used to synthesize materials containing phosphoric acid or phosphonates. Phosphonates can be coupled on the xanthene ring, and through the perpendicular structure of the spiro ring space, the steric hindrance effect of the phosphonate group can be effectively reduced; the 2,7-positions of the fluorene ring have good reactivity and are excellent modification sites for polymerization linking groups, facilitating the extension of its structure into three-dimensional space. This class of phosphoric acid-containing proton exchange membrane monomers is polymerized with different purchased polymer precursors to obtain a series of phosphonate-containing proton exchange membrane materials, which are expected to be applied in but not limited to fields such as proton exchange membranes and catalysis. Description of the Drawings

[0038] Figure 1 1H NMR characterization diagram of proton exchange membrane monomer P-1 containing phosphonate groups.

[0039] Figure 2 13C NMR characterization diagram of proton exchange membrane monomer P-1 containing phosphonate groups.

[0040] Figure 3 31P NMR characterization diagram of proton exchange membrane monomer P-1 containing phosphonate groups.

[0041] Figure 4 FT-IR characterization diagrams of different polymerization times of monomer P-1 and polymer Pol-1 and the membrane.

[0042] Figure 5 XRD pattern of monomer P-1 and polymer Pol-1.

[0043] Figure 6 SEM and EDS elemental analysis diagrams of the powder of polymer Pol-1 and the Pol-1 membrane.

[0044] Among them, a is the powder SEM image; b is the SEM image of the membrane surface; c is the SEM image of the membrane cross-section; d is the EDS elemental distribution image of the membrane magnified 30k times.

[0045] Figure 7 FT-IR characterization diagram of the powder of polymer Pol-2. Detailed Embodiments

[0046] The following non-limiting examples can enable those of ordinary skill in the art to understand the present invention more comprehensively, but do not limit the present invention in any way. Any person familiar with the technical field within the technical scope disclosed by the present invention, making equivalent substitutions or changes according to the technical solution and inventive concept of the present invention, shall fall within the protection scope of the present invention.

[0047] In the following examples, unless otherwise specified, the reagents used can be prepared by conventional methods or purchased from commercial sources.

[0048] Example 1

[0049] Synthesis of intermediate E1:

[0050]

[0051] Add 2,7-dicyano-spiro[fluorene-9,9'-xanthene] (1 g, 2.61 mmol) to a three-necked flask, then add DCM (20 ml) and place it in an ice-water bath for thorough stirring. Subsequently, slowly dropwise add bromine (0.40 ml, 7.84 mmol). After the addition is complete, raise the reaction temperature to room temperature and reflux the reaction at this temperature for 4 h. Monitor by TLC plate. After the reaction is completed, cool to room temperature, add saturated sodium sulfite solution (20 ml) to quench the reaction, filter and wash thoroughly with water to obtain a yellow solid mass, which is the crude product. Recrystallize the crude product with dichloromethane / methanol. Compound G1 is obtained as an orange-yellow powder.

[0052] Example 2

[0053] Synthesis of dicyanodiphosphonate monomer compound P1:

[0054]

[0055] Under an argon atmosphere, dissolve 2,7-dicyano-2',7'-dibromo-spiro[fluorene-9,9'-xanthene] (1 g, 1.85 mmol) and anhydrous nickel bromide (208 mg, 0.93 mmol) in mesitylene (10 ml). Stir thoroughly and raise the reaction temperature to 150 °C. Add triethyl phosphite (1.23 g, 7.40 mmol) under argon protection. Raise the temperature to 160 °C and reflux the reaction for 12 h. Monitor the reaction by TLC plate. After the reaction is completed, cool the reaction to room temperature. Remove the solvent and excess triethyl phosphite by vacuum distillation. Obtain the crude product. Subject the crude product to column chromatography separation. The eluent is PE:EA = 1:1. Compound P-1 is obtained as a white powdery solid.

[0056] The NMR data of compound P-1 is as Figures 1-3 shown.

[0057] Example 3

[0058] Synthesis of Intermediate E2:

[0059]

[0060] Refer to Example 1 for the synthesis method to synthesize Intermediate E2.

[0061] Example 4

[0062] Synthesis of Dialdehyde Diphosphonate Monomer Compound P2:

[0063]

[0064] Refer to Example 2 for the synthesis method to synthesize Dialdehyde Diphosphonate Monomer Compound P2, and the product was identified by mass spectrometry.

[0065] Example 5

[0066] Synthesis of Intermediate E3:

[0067]

[0068] Refer to Example 1 for the synthesis method to synthesize Intermediate E3, and the product was identified by mass spectrometry.

[0069] Example 6

[0070] Synthesis of Dicarboxyl Diphosphonate Monomer Compound P2:

[0071]

[0072] Refer to Example 2 for the synthesis method to synthesize Dialdehyde Diphosphonate Monomer Compound P3, and the product was identified by mass spectrometry.

[0073] Example 7

[0074] Synthesis of Bis(tetrazole) Diphosphonate Monomer P4:

[0075]

[0076] Under an argon atmosphere, add 2,7-dicyano-2',7'-dibromo-spiro[fluorene-9,9'-xanthene] (1 g, 1.53 mmol), sodium azide (397 mg, 6.11 mmol), and ammonium chloride (245 mg, 4.58 mmol) into the reaction flask. Then add DMF thereto. After stirring well, raise the reaction temperature to 120 °C and react for 24 h. Monitor whether the reaction is completed by TLC. After the reaction is completed, filter off the unreacted sodium azide and ammonium chloride by suction filtration. Collect the filtrate and concentrate it under vacuum to obtain the crude product, and then crystallize it in ethanol to obtain a white solid. The product was identified by mass spectrometry.

[0077] Example 8

[0078] Synthesis of bisacyl chloride bisphosphonate monomer compound P-5:

[0079]

[0080] Place 2,7-dicarboxy-2',7'-diethoxyphosphonyl-spiro[fluorene-9,9'-xanthene] (1 g, 1.44 mmol) in a reaction flask, set the reaction at 0 °C, and stir well for 30 min. Then add thionyl chloride (5.15 g, 43.32 mmol). Subsequently, raise the reaction temperature to 100 °C. React for 3 h. Then drop the reaction solution into ice. Filter by suction to obtain a solid product, and the product is identified by mass spectrometry.

[0081] Example 9

[0082] Synthesis of intermediate F1:

[0083]

[0084] The synthesis method refers to Example 1, and a tetra-brominated compound is generated by the method of heating bromination.

[0085] Add 2,7-dicyano-spiro[fluorene-9,9'-xanthene] (1 g, 2.61 mmol) to a three-necked flask, then add nitrobenzene (20 ml) and stir well in an ice-water bath. Subsequently, slowly dropwise add bromine (0.40 ml, 7.84 mmol). After the addition is completed, raise the reaction temperature to 100 °C and reflux the reaction at this temperature for 4 h. Monitor by TLC plate. After the reaction is completed, cool to room temperature, add saturated sodium sulfite solution (20 ml) to quench the reaction, filter and wash thoroughly with water to obtain a yellow solid block, which is the crude product. Recrystallize the crude product with dichloromethane / methanol. Compound F1 is obtained as an orange-yellow powder.

[0086] Example 10

[0087] Synthesis of dicyano tetraphosphonate monomer compound P1:

[0088]

[0089] The synthesis method refers to Example 2 to synthesize dicyano tetraphosphonate monomer compound P6, and the product is identified by mass spectrometry.

[0090] Example 11

[0091] Synthesis of intermediate F2:

[0092]

[0093] The synthesis method refers to Example 9 to synthesize a tetra-brominated compound.

[0094] Example 12

[0095] Synthesis of bis-aldehyde tetraphosphonate monomer compound P2:

[0096]

[0097] The synthesis method refers to Example 2 to synthesize bis-aldehyde tetraphosphonate monomer compound Q2, and the product is identified by mass spectrometry.

[0098] Example 13

[0099] Synthesis of intermediate F3:

[0100]

[0101] The synthesis method refers to Example 9 to synthesize a tetrabromo compound.

[0102] Example 14

[0103] Synthesis of bis-carboxyl tetraphosphonate monomer compound P2:

[0104]

[0105] The synthesis method refers to Example 3 to synthesize bis-aldehyde tetraphosphonate monomer compound Q3, and the product is identified by mass spectrometry.

[0106] Example 15

[0107]

[0108] The synthesis method refers to Example 9 to synthesize a tetrabromo compound, and then refers to Example 7 to synthesize bis-tetrazole tetraphosphonate monomer compound Q4, and the product is identified by mass spectrometry.

[0109] Example 16

[0110]

[0111] The synthesis method refers to Example 9 to synthesize a tetrabromo compound, and then refers to Example 8 to synthesize bis-acyl chloride tetraphosphonate monomer compound Q5, and the product is identified by mass spectrometry.

[0112] Example 17

[0113] Polymerization of polymer pol-1:

[0114]

[0115] Under an Ar atmosphere, add 2,7-dicyano-2',7'-dimethoxyphosphonyl-spiro[fluorene-9,9'-xanthene] (1 mg, 1.53 mmol) to a reaction flask. After cooling the reaction system to 0 °C, slowly add CF3 SO 3 H (11.46 g, 76.38 mmol), and then the reaction temperature was raised to 100 °C and reacted for 1 - 3 h. After the reaction was completed, the reaction solution was added to an ice - water mixture, and then suction filtration was carried out to obtain a dark red polymer Pol - 1 powder.

[0116] Example 18

[0117] Polymerization of polymer pol - 2:

[0118]

[0119] Under an Ar atmosphere, monomer P - 2 (1 g, 1.53 mmol) and 3,3′ - diaminobenzidine (341 mg, 1.60 mmol) were added to a reaction flask, and then 26 g of PPA was added. Subsequently, the reaction temperature was raised to 220 °C and reacted for 4 h. Then the reaction solution was added to 40 ml of deionized water. And it was washed, centrifuged, and filtered thoroughly with deionized water and ethanol. A gray powder polymer Pol - 2 was obtained. Finally, it was placed in a vacuum oven and dried for 12 h. The powder of polymer Pol - 2 was obtained. Figure 7 It is the infrared characterization diagram of polymer Pol - 2 powder. Obvious imidazole characteristic peaks appeared.

[0120] Example 19

[0121] Polymerization of polymer pol - 3:

[0122]

[0123] The synthesis method refers to Example 20 to obtain polymer Pol - 3

[0124] Example 20

[0125] Polymerization of polymer pol - 4:

[0126]

[0127] Under an inert atmosphere, monomer P4 (1 g, 1.35 mmol) and terephthaloyl chloride (288 mg, 1.42 mmol) were added to a reaction flask, and then 20 ml of pyridine was added to dissolve the reactants completely. After stirring evenly, the reaction temperature was raised to 120 °C and refluxed for 2 - 6 h. Then the reaction solution was poured into ethanol to form a precipitate, and it was filtered and washed thoroughly with deionized water and ethanol. Finally, polymer Pol - 4 was obtained, and then the polymer was placed in a vacuum oven and dried thoroughly.

[0128] Example 21

[0129] Polymerization of polymer pol - 5:

[0130]

[0131] Under an inert atmosphere, the monomer P-7 (1 g, 1.37 mmol) and 5,5′-(1,4-phenylene)bis(2H-tetrazole) (300 mg, 1.4 mmol) were added to a reaction flask, and then 20 ml of pyridine was added to dissolve the reactants completely. After stirring evenly, the reaction temperature was raised to 120 °C and refluxed for 2 h - 6 h. Then the reaction solution was poured into ethanol to form a precipitate, which was filtered and washed thoroughly with deionized water and ethanol. Finally, the polymer Pol-6 was obtained, and then the polymer was placed in a vacuum oven for thorough drying.

[0132] Example 22

[0133] Polymerization of polymer pol-6:

[0134]

[0135] The polymerization method was referred to Example 17 to obtain the polymer Pol-6.

[0136] Example 23

[0137]

[0138] The synthesis method was referred to Example 18 to obtain the polymer Pol-7.

[0139] Example 24

[0140]

[0141] The synthesis method was referred to Example 19 to obtain the polymer Pol-8.

[0142] Example 25

[0143]

[0144] The synthesis method was referred to Example 20 to obtain the polymer Pol-9.

[0145] Example 26

[0146]

[0147] The synthesis method was referred to Example 21 to obtain the polymer Pol-10.

[0148] Example 27

[0149] Under an Ar atmosphere, 200 mg of monomeric compound P1 was added to a reaction flask. Subsequently, the temperature of the system was lowered to 0 °C, and trifluoromethanesulfonic acid was added thereto, followed by thorough stirring for 30 min - 3 h. A red viscous liquid was obtained. Subsequently, the liquid was spread on a glass plate under Ar and heated at 100 °C for 1 - 3 h. A dark red soft baked body was obtained. Subsequently, the glass plate was placed in a vacuum oven and dried at 120 °C for 2 h to obtain a continuous film. Ultra-pure water was added to separate the film from the glass substrate and remove the last unreacted trifluoromethanesulfonic acid. Finally, the film was placed in a vacuum oven and dried at 80 °C for 24 h. The significant change in the degree of polymerization before and after crosslinking polymerization verified the success of crosslinking polymerization.

[0150] Take 3 - 5 mg of the fully dried sample, grind it into powder in a mortar, and press the powder sample into a tablet using the KBr tablet pressing method to obtain the infrared absorption spectra ( Figure 4 ) of the monomer and the polymer to analyze the positions and intensities of the characteristic peaks in the monomer structure and the polymer structure. From Figure 4 the infrared spectra of the monomer and the polymer, it can be seen that the cyano group peak at 2223 cm-1 almost disappeared, and the peaks of C-N and C=N at 1503 cm-1 and 1361 cm-1 appeared significantly. It was confirmed that the cyano group was almost completely polymerized under the catalysis of trifluoromethanesulfonic acid.

[0151] XRD was used to detect whether the polymer monomer and the polymer exhibited a regular crystal structure. After grinding the sample into fine powder with an agate mortar. The sample was spread flat in the sample groove of the sample holder, and the sample was pressed flat and compacted with another sample holder to remove the excess sample. The sample holder was inserted into the sample stage of the diffractometer and aligned with the center line. The scanning range was 5 - 40°, and the scanning speed was selected as 1° / min to obtain the XRD spectra ( Figure 5 ) of the monomer and the polymer. Through Figure 5 XRD diffraction analysis, it was characterized that the obtained crosslinked polymer was an amorphous covalent polymer (COP).

[0152] When studying the microscopic morphology of the membrane surface, the sample was first treated with liquid nitrogen, quenched and broken to obtain a sample with a better cross-sectional morphology, and then the membrane material was sputter-coated with gold. When studying the microscopic morphology of the membrane material surface, a sample of appropriate size was appropriately selected and its surface was sputter-coated with gold. Subsequently, energy-dispersive X-ray spectroscopy analysis of the dispersion and content of phosphorus element was carried out on an electron image magnified 30000 times. From Figure 6 the SEM surface and cross-sectional images of the crosslinked membrane, it can be seen that a continuous membrane structure was formed and a uniform microporous structure was formed due to the hydrogen bond interaction between phosphoric acids. Through EDS elemental analysis, it was obtained that its phosphate groups were uniformly distributed around the hydrogen bond holes. It was proved that a triazine polyphosphate polymer membrane with hydrogen bond micropores was formed.

[0153] Example 28

[0154] For the polymer ion exchange capacity test, the polymer membrane Pol-1 was ground into powder and dried thoroughly in a vacuum oven at 100 °C for 48 h. At the same time, the commercially available proton exchange membrane Nafion powder was dried. After drying, 100 mg of Pol-1 powder and 100 mg of Nafion powder were weighed respectively. Then, both were immersed in 2 M sodium chloride solution for 72 h. Finally, using an acid-base indicator (1 M phenolphthalein), titration was carried out with 0.02 M NaOH, and the volume of the alkali solution consumed when the solution changed color was recorded.

[0155] IEC = M NaOH / W dry

[0156] Among them, IEC (mmol / g) represents the ion exchange capacity; M NaOH represents the amount of substance of sodium hydroxide consumed; W dry represents the mass of the dry powder. Through IEC analysis, it can be known that more than 90% of the phosphonic acid groups are expressed after polymerization. Table 1 shows the ion exchange capacity data of the polymer Pol-1 membrane and the commercially available Nafion membrane powder. From the data in the table, it can be seen that the ion exchange data of the polymer Pol-1 membrane is more than five times that of the commercial membrane, proving that it has a good hydrogen bond network system.

[0157] Table 1 IEC values of Pol-1 and Nafion

[0158]

[0159] Example 29

[0160] Referring to the methods of Example 27 and Example 28, the same tests were carried out on the polymers Pol-2 and Pol-4. The polymers Pol-2 and Pol-4 also formed a continuous membrane structure and a uniform microporous structure due to the hydrogen bond interaction between phosphoric acids. Through EDS elemental analysis, it can be obtained that its phosphonic acid groups are evenly distributed around the hydrogen bond holes, and two polymerization regions also formed a polyphosphoric acid polymer membrane with hydrogen bond micropores. Through the ion exchange capacity test, the ion exchange data of the polymers Pol-2 and Pol-4 membranes are both significantly higher than that of the commercial membrane.

Claims

1. A compound of formula I: Wherein, X is independently selected from R1 is R2 is or Y is each independently a C1-C3 alkyl group.

2. The compound according to claim 1, Characterized in that, X is 3. A class of proton exchange membrane materials containing phosphate groups, Characterized in that, The material has a structure of formula II or formula III: wherein, R3 is R4 is or n is an integer; Z are each independently selected from 4. The proton exchange membrane material according to claim 3, Characterized in that, R3 is R4 is 5. The proton exchange membrane material according to claim 3, Characterized in that, The material has the following structure:

6. Use of the compound according to claim 1 in the preparation of a proton exchange membrane material containing phosphate groups.

7. Use of the proton exchange membrane material according to claim 3 in the preparation of a proton exchange membrane.

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