CN108767298B - A kind of organic polymer cross-linked organic phosphonic acid high temperature proton exchange membrane and preparation method thereof - Google Patents

Abstract

The present invention provides an organic polymer cross-linked organic phosphonic acid high temperature proton exchange membrane and a preparation method thereof. Specifically, the present invention provides (a) polybenzimidazole type compound A, (b) "acid-base""type organic phosphonic acid polymer B and (c) organic polymer cross-linking agent C as raw materials composite high temperature proton exchange membrane. The organic polymer cross-linked organic phosphonic acid high temperature proton exchange membrane of the present invention has high proton conductivity, high mechanical strength, high anti-oxidative stability and low phosphonic acid loss rate, and is very suitable for high temperature proton exchange membrane fuel cells. preparation.

Description

A kind of organic polymer cross-linked organic phosphonic acid high temperature proton exchange membrane and its preparation method

technical field

The invention belongs to the technical field of fuel cells, and in particular relates to an organic polymer cross-linked organic phosphonic acid high temperature proton exchange membrane and a preparation method thereof.

Background technique

Proton exchange membrane fuel cell power generation is a new generation of high-efficiency and environmentally friendly power generation technology, and its broad application prospects are comparable to computer technology. It uses a solid proton exchange membrane as the electrolyte, and there is no electrolyte corrosion problem. At the same time, it has the characteristics of high energy conversion efficiency, low pollution, fast start-up, long life and high power density. Mobile power supply, backup power supply and other aspects have broad application prospects, especially the best driving power supply for electric vehicles. After years of basic research and application development, substantial progress has been made in the study of proton exchange membrane fuel cells used as vehicle power. The miniature proton exchange membrane fuel cell portable power supply and the small proton exchange membrane fuel cell portable power supply have reached the level of commercialization. , The research of high-power proton exchange membrane fuel cell power generation system has also achieved certain results.

Traditional PEMFC (Proton Exchange Membrane Fuel Cell) generally works at 60-90°C, and the lower working temperature brings various disadvantages to PEMFC, such as catalyst poisoning and complicated hydrothermal management, which seriously limit the traditional PEMFC fuel. battery development. Therefore, in order to solve the above problems of traditional PEMFC proton exchange membrane fuel cells, the development of high temperature proton exchange membrane fuel cells (HT-PEMFC) is inevitable. High temperature proton exchange membrane fuel cells have distinct advantages: (1) improved CO tolerance of the catalyst; (2) improved reaction and diffusion rates; (3) simplified water management of the battery system; (4) simplified battery The thermal management of the system; (5) the Pt loading of the catalyst can be reduced and non-platinum-based catalysts can be developed to reduce the cost of the entire PEMFC. The high temperature proton exchange membrane (HT-PEM) is the core of the high temperature proton exchange membrane fuel cell (HT-PEMFC) to achieve high temperature operation.

At present, the widely used high temperature proton exchange membrane is PBI (polybenzimidazole) type proton exchange membrane, and the biggest disadvantage of this system is the loss of inorganic phosphoric acid. Therefore, in order to solve the problem of the loss of inorganic phosphoric acid, the high temperature proton exchange membrane of organic phosphonic acid has become an inevitable development direction.

At present, there are many methods for preparing high temperature proton exchange membranes of organic phosphonic acid, but there are still some problems. For example, the preparation of organic phosphonic acid polymers is difficult. For example, the method of linking vinylphosphonic acid to PPO and PSU requires low-temperature, anhydrous and oxygen-free operation, and the solubility of PPO and PSU is poor, which is not suitable for large-scale production; in addition, existing The production process of the organic phosphonic acid high temperature proton exchange membrane is complex, such as the product launched by BASF, the process is very complicated, and the batch stability of the product is poor; finally, the phosphonic acid content cannot be accurately controlled, and the conductivity regulation is difficult, such as PBI The membrane is immersed in a solution containing vinyl phosphoric acid and then polymerized, and the phosphonic acid content in this system cannot be accurately controlled.

To sum up, there is still a lack of a high-temperature proton exchange membrane with simple preparation of organic phosphonic acid polymer, simple membrane preparation process, accurate and controllable organic phosphonic acid content and proton conductivity in the art, and a preparation method thereof.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a high-temperature proton exchange membrane with simple preparation of organic phosphonic acid polymer, simple membrane preparation process, accurate and controllable content of organic phosphonic acid and proton conductivity, and preparation method thereof.

The first aspect of the present invention provides an organic polymer cross-linked organic phosphonic acid high temperature proton exchange membrane, the organic polymer cross-linked organic phosphonic acid high temperature proton exchange membrane is made of (a) polybenzimidazole Type compound A, (b) "acid-base" type organic phosphonic acid polymer B and (c) organic macromolecular crosslinking agent C are composited as raw materials, wherein the molar ratio nA of described A and B: nB=1:0.01-99.99;

Described "acid-base" type organic phosphonic acid polymer B is a copolymer formed by the copolymerization of basic olefin monomer D and organic phosphonic acid monomer E, wherein basic olefin monomer D is selected from the following group:

Among them, the organic phosphonic acid monomer E is selected from the following group:

R ² is selected from the group consisting of H, substituted or unsubstituted C1-C9 alkyl, phenyl (Ph), TMS (Me ₃ Si, trimethylsilyl), TES (Et ₃ Si, triethylsilyl) base), TBS (tert-butyldimethylsilyl), TIPS (triisopropylsilyl), TBDPS (tert-butyldiphenylsilyl).

In another preferred embodiment, the polybenzimidazole polymer A is selected from the following group:

Among them, n=2-10000;

R is selected from the group consisting of none, O, S, NH, C(O), S(O) ₂ , unsubstituted or halogenated C1-C6 alkylene, unsubstituted or halogenated C2-C6 alkenylene ;

R ¹ is selected from the following group:

In another preferred embodiment, the polybenzimidazole type compound A is selected from the following group:

wherein R ¹ is as defined above.

In another preferred example, the molar ratio of the copolymerization of monomer D and monomer E is nD:nE=1:0.01-99.99; and/or

The molar ratio of A to C is nA:nC=1:0.01-10.00.

In another preferred example, the "acid-base" type organic phosphonic acid polymer B is prepared by the following method: in deionized water, the monomer D and the organic phosphonic acid monomer E are used for polymerization reaction to obtain the polymer B.

In another preferred embodiment, the reaction is carried out under nitrogen protection.

In another preferred embodiment, the reaction is carried out in the presence of an initiator; preferably, the initiator is a free radical chain initiator; more preferably, the molar amount of the initiator is monomer D 0.1%-5% of the total molar amount of the organic phosphonic acid monomer E.

In another preferred example, the "acid-base" type organic phosphonic acid polymer B containing a hydroxyl functional group or the hydroxyl group protected by a protecting group is prepared by the following method:

(1) under nitrogen protection, add monomer D and organic phosphonic acid monomer E successively to the three-necked reaction flask, use deionized water as solvent, then add free radical chain initiator azobisisobutyronitrile (AIBN), The molar amount of AIBN is 0.1%-5% of the total molar amount of monomer D and organic phosphonic acid monomer E;

(2) Stirring (mechanical stirring), heating to 80°C to react. After 24 hours of reaction, the solution became viscous, the reaction was stopped, and it was cooled to room temperature. The reaction solution was poured into ethyl acetate and stirred continuously, and a solid was precipitated, which was filtered and dried to obtain an "acid-base" type organic phosphonic acid polymer B.

In another preferred example, the organic polymer crosslinking agent C is selected from the following group:

where m=2-10000.

In another preferred example, the molar ratio of A and B is nA:nB=1:0.1-40, and the molar ratio of A and C is nA:nC=1:0.02-10.00.

The second aspect of the present invention provides a method for preparing a high-temperature proton exchange membrane of organic polymer cross-linked organic phosphonic acid as described in the first aspect of the present invention. The preparation method of the exchange membrane is as follows:

(i) providing a polybenzimidazole type compound A and an "acid-base" type organic phosphonic acid polymer B;

(ii) under the protection of inert gas, the mixture of the two is dissolved in an organic solvent to form a mixed solution;

(iii) cooling the mixed solution to room temperature, adding organic polymer cross-linking agent C, stirring for two hours, and stirring uniformly;

(iv) filtering to remove insolubles to obtain a mixed filtrate;

(v) degassing the mixed filtrate;

(vi) forming a membrane from the degassed mixed filtrate to obtain a high-temperature proton exchange membrane of an organic phosphonic acid cross-linked by an organic polymer.

In another preferred example, the molar ratio of the polybenzimidazole type compound A and the "acid-base" type organic phosphonic acid polymer B is 1:0.1-40, and the polybenzimidazole type compound A and the organic polymer are cross-linked The molar ratio of agent C is 1:0.02-10.00.

In another preferred example, the organic solvent is a strong polar organic solvent, preferably selected from the following group: DMSO (dimethyl sulfoxide), DMF (N,N-dimethylformamide), DMAC (N,N-dimethylacetamide), or NMP (N-methylpyrrolidone), or a combination thereof.

In another preferred example, in the step (ii), the solid content of the prepared solution is 1-30 wt %.

In another preferred embodiment, the film forming comprises: coating a glass plate or a plastic film and drying to form a high temperature proton exchange membrane of organic phosphonic acid cross-linked by an organic polymer.

In another preferred embodiment, the coating method is a casting method.

In another preferred embodiment, the drying includes: after preliminary drying at 70-90°C, the temperature is raised to 100-160°C for the second step of drying, and then the temperature is raised to 160-300°C for the third step of drying.

It should be understood that within the scope of the present invention, the above-mentioned technical features of the present invention and the technical features specifically described in the following (eg, the embodiments) can be combined with each other to form new or preferred technical solutions. Due to space limitations, it is not repeated here.

Description of drawings

1 is a graph of the proton conductivity of the organic phosphonic acid high temperature proton exchange membrane and the PBI membrane in Examples 2, 4, 6, 7, 9, 13, 14 and 15 as a function of temperature.

2 is a comparison chart of the test results of the loss rate of phosphoric acid (phosphonic acid) for the high temperature proton exchange membranes prepared in Examples 2, 6, 7 and 15.

FIG. 3 is a single cell discharge graph of the high temperature proton exchange membranes prepared in Examples 1, 2 and 14. FIG.

FIG. 4 is a single cell working stability test chart of the high temperature proton exchange membranes prepared in Examples 1, 4 and 15. FIG.

Detailed ways

After long-term and in-depth research, the inventors found that after the polybenzimidazole type compound A and another "acid-base" type organic phosphonic acid polymer B were used to form a solution, the organic polymer crosslinking agent C was added. , After mixing evenly, it is cast to form a film. After drying, a high-temperature proton exchange membrane with high proton conductivity, high mechanical strength, high thermal stability, high anti-oxidative stability and low swelling rate can be obtained, so it is very suitable for use as Proton exchange membranes for high temperature proton conducting membrane fuel cells. Based on the above findings, the inventors have completed the present invention.

Compared with the traditional high temperature proton exchange membrane of polybenzimidazole (PBI) type, the organic polymer cross-linked organic phosphonic acid high temperature proton exchange membrane of the present invention has the following advantages:

1) No inorganic phosphonic acid is used, and there is no problem of loss of inorganic phosphonic acid;

2) There is no contradiction between the mechanical strength of the membrane and the proton conductivity of the membrane;

3) There is no poisoning effect of inorganic phosphoric acid exudation on the catalyst;

Compared with the reported organic phosphonic acid high temperature proton exchange membrane, it has the following advantages:

1) The preparation method of the organic phosphonic acid polymer is simple and suitable for large-scale preparation;

2) The film-making process is simple, suitable for mass production, and has good repeatability;

3) The content of organic phosphonic acid is accurate and controllable;

4) Proton conductivity can be adjusted with the change of phosphonic acid content;

5) The swelling rate of the proton exchange membrane material is low;

6) The thermal stability and anti-oxidative stability of the membrane material are significantly enhanced;

7) The glass transition temperature of the polymer film is increased, and the high temperature resistance performance is better;

8) The mechanical strength of the membrane material is high;

Therefore, the organic high temperature proton exchange membrane of the present invention will have higher mechanical strength, higher proton conductivity, higher dimensional stability, higher working stability and durability, which is beneficial to promote the commercialization of high temperature fuel cells development.

The present invention will be further described below in conjunction with specific embodiments. It should be understood that these examples are only used to illustrate the present invention and not to limit the scope of the present invention. In the following examples, the experimental methods without specific conditions are usually in accordance with conventional conditions, or in accordance with the conditions suggested by the manufacturer. Percentages and parts are by weight unless otherwise indicated.

Example 1

Preparation of composite films of m-PBI with [N-vinylimidazole-vinylphosphonic acid bis(trimethylsilyl) ester] copolymer B ₁ and organic polymer cross-linking agent C ₁

(1) Preparation of N-vinylimidazole-vinylphosphonic acid bis(trimethylsilyl) ester copolymer B ₁ (mol ratio 1:4):

Under nitrogen protection, N-vinylimidazole (282.3 mg, 3 mmol) and vinylphosphonic acid bis(trimethylsilyl) ester (3028.7 mg, 12 mmol) were successively added to the three-necked reaction flask, followed by deionized water (200 mL) As a solvent, the radical chain initiator azobisisobutyronitrile (AIBN, 24.63 mg, 0.15 mmol) was then added. Stir (mechanical stirring), heat to 80°C to react. After 24 hours of reaction, the solution became viscous, the reaction was stopped, and it was cooled to room temperature. The reaction solution was poured into ethyl acetate and stirred continuously, and a solid was precipitated, which was filtered and dried in vacuo to obtain copolymer B ₁ .

(2) Preparation of composite film of m-PBI, copolymer B ₁ and organic polymer cross-linking agent C ₁ (molar ratio 1:2:0.1)

Dry m-PBI (154.2 mg, 0.5 mmol) and copolymer B ₁ (1103.7 mg, 1.0 mmol) were weighed in a molar ratio of 1:2:0.1. Under the protection of nitrogen, the mixture of the two was dissolved in dry DMSO (dimethyl sulfoxide, 23.900 g), heated to prepare a solution with a solid content of 5%, cooled to room temperature, and organic polymer cross-linking was added. Agent C ₁ (26.2 mg, 0.05 mmol), stirred for 2 hours, stirred evenly, filtered, and filtered off insoluble matter, the filtrate was degassed and cast onto a 10 cm×10 cm glass plate, and then placed in a blast oven at Dry at 80°C for two hours, then further heat up to 120°C and dry for one hour, and finally heat up to 240°C and dry for one hour to obtain an organic phosphonic acid high temperature proton exchange membrane. The thickness of the film is 24 μm (micrometer), the DSC test shows that its glass transition temperature is T _g =321°C, and the mechanical property test shows that its tensile strength is 109 MPa.

Example 2

Preparation of composite films of Py-PBI with [2-vinylimidazole-allylphosphonic acid bis(triethylsilyl)ester] copolymer B ₂ and organic polymer crosslinking agent C ₂

(1) Preparation of 2-vinylimidazole-allylphosphonic acid bis(triethylsilyl) ester copolymer B ₂ (molar ratio 1:3)

Under nitrogen protection, 2-vinylimidazole (282.3 mg, 3 mmol) and bis(triethylsilyl) allylphosphonate (3155.2 mg, 9 mmol) were successively added to the three-necked reaction flask, followed by deionized water (200 mL). ) as a solvent, and then the radical chain initiator azobisisobutyronitrile (AIBN, 19.71 mg, 0.12 mmol) was added. Stir (mechanical stirring), heat to 80°C to react. After 24 hours of reaction, the solution became viscous, the reaction was stopped, and it was cooled to room temperature. The reaction solution was poured into ethyl acetate and stirred continuously, and a solid was precipitated, which was filtered and dried in vacuo to obtain copolymer B ₂ .

(2) Preparation of composite film of Py-PBI, copolymer B ₂ and organic polymer cross-linking agent C ₂ (molar ratio 1:1:0.2)

Dry Py-PBI (154.5 mg, 0.5 mmol) and Copolymer B ₂ (572.3 mg, 0.5 mmol) were weighed in a molar ratio of 1:1:0.2. Under the protection of nitrogen, the mixture of the two was dissolved in dry DMF (N,N-dimethylformamide, 17.443 g), heated and stirred to prepare a solution with a solid content of 4%, cooled to room temperature, added Organic polymer cross-linking agent C ₂ (67.9 mg, 0.1 mmol), stirred for 2 hours, stirred evenly, filtered, filtered off insolubles, the filtrate was degassed and cast on a 10cm×10cm glass plate, and then placed on Dry at 80°C for two hours in a forced air oven, then further heat up to 120°C and dry for one hour, and finally heat up to 230°C and dry for one hour to obtain an organic phosphonic acid high temperature proton exchange membrane. The thickness of the film is 22 μm (micrometer), the DSC test shows that its glass transition temperature is T _g =320° C., and the mechanical property test shows that its tensile strength is 107 MPa.

Example 3

Preparation of composite films of O-PBI with [1-vinylpyrazole-1,1-vinyldiphosphonate tetramethyl ester] copolymer B ₃ and organic polymer cross-linking agent C ₃

(1) Preparation of 1-vinylpyrazole-1,1-vinyldiphosphonate tetramethyl copolymer B ₃ (molar ratio 1:2)

Under nitrogen protection, 1-vinylpyrazole (282.3 mg, 3 mmol) and tetramethyl 1,1-vinyl diphosphonate (1464.7 mg, 6 mmol) were successively added to the three-necked reaction flask, followed by deionized water (200 mL). ) as a solvent, and then the radical chain initiator azobisisobutyronitrile (AIBN, 14.78 mg, 0.09 mmol) was added. Stir (mechanical stirring), heat to 80°C to react. After 24 hours of reaction, the solution became viscous, the reaction was stopped, and it was cooled to room temperature. The reaction solution was poured into ethyl acetate and stirred continuously, a solid was precipitated, filtered and dried in vacuo to obtain copolymer B ₃

(2) Preparation of composite film of O-PBI, copolymer B ₃ and organic polymer cross-linking agent C ₃ (molar ratio 1:3:0.15)

Dry O-PBI (200.2 mg, 0.5 mmol) and Copolymer _B3 (873.4 mg, 1.5 mmol) were weighed in a molar ratio of 1:3:0.15. Under the protection of nitrogen, the mixture of the two was dissolved in dry DMAC (N,N-dimethylacetamide, 13.420 g), heated and stirred to prepare a solution with a solid content of 8%, cooled to room temperature, added Organic polymer cross-linking agent C ₃ (90.0 mg, 0.15 mmol), stirred for 2 hours, stirred evenly, filtered, filtered off insolubles, the filtrate was degassed and cast on a 10cm×10cm glass plate, and then placed on Dry at 80°C for two hours in a forced air oven, then further heat up to 120°C and dry for one hour, and finally heat up to 250°C and dry for one hour to obtain an organic phosphonic acid high temperature proton exchange membrane. The thickness of the film is 26 μm (micrometer), the DSC test shows its glass transition temperature T _g =314°C, and the mechanical property test shows that its tensile strength is 102 MPa.

Example 4

The composite film of OSO ₂ -PBI with [N-vinylimidazole-2-propenyl (2-methylene phosphonate diethyl) phosphonate] copolymer B ₄ and organic polymer cross-linking agent C ₄ preparation

(1) Preparation of N-vinylimidazole-2-propenyl(diethyl2-methylenephosphonate)diethylphosphonate copolymer B ₄ (molar ratio 1:4)

Under nitrogen protection, N-vinylimidazole (94.1 mg, 1 mmol) and 2-propenyl (diethyl 2-methylene phosphonate) diethyl phosphonate (1464.7 mg, 4 mmol) were sequentially added to the three-necked reaction flask ), deionized water (180 mL) was used as a solvent, and then the radical chain initiator azobisisobutyronitrile (AIBN, 8.2 mg, 0.05 mmol) was added. Stir (mechanical stirring), heat to 80°C to react. After 24 hours of reaction, the solution became viscous, the reaction was stopped, and it was cooled to room temperature. The reaction solution was poured into ethyl acetate and stirred continuously, and a solid was precipitated, which was filtered and dried in vacuo to obtain copolymer B ₄ .

(2) Preparation of composite membrane of OSO ₂ -PBI, copolymer B ₄ and organic polymer cross-linking agent C ₄ (molar ratio 1:0.5:0.05)

Dry _{OSO2 -} PBI (464.1 mg, 1.0 mmol) and Copolymer B4 (703.5 mg, 0.5 mmol) were weighed in a molar ratio of 1:0.5:0.05. Under the protection of nitrogen, the mixture of the two was dissolved in dry DMAC (N,N-dimethylacetamide, 22.185 g), heated and stirred to prepare a solution with a solid content of 5%, cooled to room temperature, added Organic polymer cross-linking agent C ₄ (36.7 mg, 0.05 mmol), stirred for 2 hours, stirred evenly, filtered, and filtered off insoluble matter, the filtrate was degassed and cast onto a 10cm×10cm glass plate, and then placed on Dry at 80°C for two hours in a forced air oven, then further heat up to 120°C and dry for one hour, and finally heat up to 220°C and dry for one hour to obtain an organic phosphonic acid high temperature proton exchange membrane. The thickness of the film is 28 μm (micrometer), the DSC test shows its glass transition temperature T _g =322°C, and the mechanical property test shows that its tensile strength is 109 MPa.

Example 5

Preparation of composite films of F ₆ -PBI with [1-vinyltriazole-dimethyl vinylphosphonate] copolymer B ₅ and organic polymer cross-linking agent C ₅

(1) preparation of 1-vinyl triazole-dimethyl vinyl phosphonate copolymer B ₅ (mol ratio 1:5):

Under nitrogen protection, 1-vinyl triazole (190.2 mg, 2 mmol) and dimethyl vinyl phosphonate (1360.9 mg, 10 mmol) were successively added to the three-necked reaction flask, and deionized water (200 mL) was used as a solvent, The free radical chain initiator azobisisobutyronitrile (AIBN, 9.9 mg, 0.06 mmol) was then added. Stir (mechanical stirring), heat to 80°C to react. After 24 hours of reaction, the solution became viscous, the reaction was stopped, and it was cooled to room temperature. The reaction solution was poured into ethyl acetate and stirred continuously, and a solid was precipitated, which was filtered and dried in vacuo to obtain copolymer B ₅ .

(2) Preparation of composite film of F ₆ -PBI, copolymer B ₅ and organic polymer cross-linking agent C ₅ (molar ratio 1:5:0.3)

Dry F6 _- PBI (267.3 mg, 0.5 mmol) and copolymer B5 (1937.9 mg, _2.5 mmol) were weighed in a molar ratio of 1:5:0.3. Under the protection of nitrogen, the mixture of the two was dissolved in dry NMP (N-methylpyrrolidone 19.847g), heated and stirred to prepare a solution with a solid content of 10%, cooled to room temperature, added with organic macromolecules for cross-linking Agent C ₅ (99.6 mg, 0.15 mmol), stirred for 2 hours, stirred evenly, filtered, and filtered off the insolubles, the filtrate was degassed and cast onto a 10cm×10cm glass plate, and then placed in a blast oven at Dry at 80°C for two hours, then further heat up to 120°C and dry for one hour, and finally heat up to 240°C and dry for one hour to obtain an organic phosphonic acid high temperature proton exchange membrane. The thickness of the film was 29 μm (micrometers), the DSC test showed that its glass transition temperature was T _g =285°C, and the mechanical property test showed that its tensile strength was 101 MPa.

Example 6

OO-PBI and [1-vinyl-1H-1,2,3-triazole-allylphosphonic acid bis(triisopropylsilyl)ester] copolymer B ₆ and organic polymer cross-linking agent C ₆ Preparation of composite membranes

(1) Preparation of 1-vinyl-1H-1,2,3-triazole-allylphosphonic acid bis(triisopropylsilyl) ester copolymer B ₆ (molar ratio 1:6)

Under nitrogen protection, 1-vinyl-1H-1,2,3-triazole (95.1 mg, 1 mmol) and bis(triisopropylsilyl) allylphosphonate ( 2692.6 mg, 6 mmol) in deionized water (200 mL) as solvent, and then the radical chain initiator azobisisobutyronitrile (AIBN, 11.5 mg, 0.07 mmol) was added. Stir (mechanical stirring), heat to 80°C to react. After 24 hours of reaction, the solution became viscous, the reaction was stopped, and it was cooled to room temperature. The reaction solution was poured into ethyl acetate and stirred continuously, and a solid was precipitated, which was filtered and dried in vacuo to obtain copolymer B ₆ .

(2) Preparation of composite film of OO-PBI with copolymer B ₆ and organic polymer cross-linking agent C ₆ (molar ratio 1:1:0.4)

Dry OO-PBI (246.8 mg, 0.5 mmol) and copolymer B6 ( _1393.9 mg, 0.5 mmol) were weighed in a molar ratio of 1:1:0.4. Under the protection of nitrogen, the mixture of the two was dissolved in dry NMP (N-methylpyrrolidone 25.704g), heated and stirred to prepare a solution with a solid content of 6%, cooled to room temperature, and added with organic polymers for cross-linking Agent C ₆ (159.6 mg, 0.2 mmol), stirred for 2 hours, stirred evenly, filtered, and filtered off the insolubles, the filtrate was degassed and cast onto a 10cm×10cm glass plate, and then placed in a blast oven at Dry at 80°C for two hours, then further heat up to 120°C and dry for one hour, and finally heat up to 240°C and dry for one hour to obtain an organic phosphonic acid high temperature proton exchange membrane. The thickness of the film is 27 μm (micrometer), the DSC test shows that its glass transition temperature is Tg=316° C., and the mechanical property test shows that its tensile strength is 105 MPa.

Example 7

Py-O-PBI and [N-vinyl-1,3,4-triazole-1,1-vinyldiphosphonic acid tetraphenyl ester] copolymer B ₇ and organic polymer cross-linking agent C ₇ composite membrane preparation

(1) Preparation of N-vinyl-1,3,4-triazole-1,1-vinyldiphosphonic acid tetraphenyl ester copolymer B ₇ (molar ratio 1:5)

Under nitrogen protection, N-vinyl-1,3,4-triazole (95.1 mg, 1 mmol) and tetraphenyl 1,1-vinyl diphosphonate (2460.4 mg, 5 mmol) were successively added to the three-necked reaction flask. ), deionized water (200 mL) was used as a solvent, and then the radical chain initiator azobisisobutyronitrile (AIBN, 9.9 mg, 0.06 mmol) was added. Stir (mechanical stirring), heat to 80°C to react. After 24 hours of reaction, the solution became viscous, the reaction was stopped, and it was cooled to room temperature. The reaction solution was poured into ethyl acetate and stirred continuously, and a solid was precipitated, which was filtered and dried in vacuo to obtain copolymer B ₇ .

(2) Preparation of composite film of Py-O-PBI with copolymer B ₇ and organic polymer cross-linking agent C ₇ (molar ratio 1:0.2:0.5)

Dry Py-O-PBI (355.4 mg, 1 mmol) and Copolymer B ₇ (511.1 mg, 0.2 mmol) were weighed in a molar ratio of 1:0.2:0.5. Under the protection of nitrogen, the mixture of the two was dissolved in dry DMAC (N,N-dimethylacetamide, 42.460 g), heated and stirred to prepare a solution with a solid content of 2%, cooled to room temperature, and added Organic polymer cross-linking agent C ₇ (94.0 mg, 0.5 mmol), stirred for 2 hours, stirred evenly, filtered, filtered off insolubles, the filtrate was degassed and cast on a 10cm×10cm glass plate, and then placed on Dry at 80°C for two hours in a forced air oven, then further heat up to 120°C and dry for one hour, and finally heat up to 240°C and dry for one hour to obtain an organic phosphonic acid high temperature proton exchange membrane. The thickness of the film is 30 μm (micrometer), the DSC test shows that its glass transition temperature is T _g =330°C, and the mechanical property test shows that its tensile strength is 109 MPa.

Example 8

p-PBI and [1-vinyltriazole-2-propenyl[2-methylenephosphonate bis(trimethylsilyl)ester]phosphonate bis(trimethylsilyl)ester] copolymer B ₈ and Preparation of organic polymer cross-linking agent C ₈ composite membrane

(1) 1-Vinyltriazole-2-propenyl[2-methylenephosphonate bis(trimethylsilyl)ester]phosphonate bis(trimethylsilyl)ester copolymer B ₈ (molar ratio 1 :5) preparation

Under nitrogen protection, 1-vinyltriazole (95.1 mg, 1 mmol) and 2-propenyl[2-methylenephosphonic acid bis(trimethylsilyl) ester]phosphonic acid were added to the three-necked reaction flask in turn. (Trimethylsilyl)ester (2520.8 mg, 5 mmol), deionized water (200 mL) as solvent, and then the radical chain initiator azobisisobutyronitrile (AIBN, 9.9 mg, 0.06 mmol) was added. Stir (mechanical stirring), heat to 80°C to react. After 24 hours of reaction, the solution became viscous, the reaction was stopped, and it was cooled to room temperature. The reaction solution was poured into ethyl acetate and stirred continuously, and a solid was precipitated, which was filtered and dried in vacuo to obtain copolymer B ₈ .

(2) Preparation of p-PBI and copolymer B ₈ and organic polymer cross-linking agent C ₈ composite film (molar ratio 1:0.1:0.6)

Dry p-PBI (616.7 mg, ₂ mmol) and copolymer B8 (523.2 mg, 0.2 mmol) were weighed in a molar ratio of 1:0.1:0.6. Under the protection of nitrogen, the mixture of the two was dissolved in dry DMAC (N,N-dimethylacetamide, 27.357g), heated and stirred to prepare a solution with a solid content of 4%, cooled to room temperature, added Organic polymer cross-linking agent C ₈ (333.6 mg, 1.2 mmol), stirred for 2 hours, stirred evenly, filtered, filtered off insolubles, the filtrate was degassed and cast on a 10cm×10cm glass plate, and then placed on Dry at 80°C for two hours in a forced air oven, then further heat up to 120°C and dry for one hour, and finally heat up to 240°C and dry for one hour to obtain an organic phosphonic acid high temperature proton exchange membrane. The thickness of the film was 32 μm (micrometer), the DSC test showed that its glass transition temperature T _g =329° C., and the mechanical property test showed that its tensile strength was 120 MPa.

Example 9

Preparation of SO ₂ -PBI and [N-vinylbenzimidazole-vinylphosphonic acid bis(trimethylsilyl)ester] copolymer B ₉ and organic polymer cross-linking agent C ₉ composite membrane

(1) Preparation of N-vinylbenzimidazole-vinylphosphonic acid bis(trimethylsilyl) ester copolymer B ₉ (molar ratio 1:8)

Under nitrogen protection, N-vinyl benzimidazole (144.2 mg, 1 mmol) and vinyl phosphonate bis(trimethylsilyl) ester (2016.6 mg, 8 mmol) were successively added to the three-necked reaction flask, and deionized water ( 250 mL) as a solvent, and then the radical chain initiator azobisisobutyronitrile (AIBN, 29.6 mg, 0.18 mmol) was added. Stir (mechanical stirring), heat to 80°C to react. After 24 hours of reaction, the solution became viscous, the reaction was stopped, and it was cooled to room temperature. The reaction solution was poured into ethyl acetate and stirred continuously, and a solid was precipitated, which was filtered and dried in vacuo to obtain copolymer B ₉ .

(2) Preparation of composite membrane of SO ₂ -PBI, copolymer B ₉ and organic polymer cross-linking agent C ₉ (molar ratio 1:0.3:0.8)

Dry SO2 _- PBI (494.6 mg, 1 mmol) and copolymer B9 ( _648.2 mg, 0.3 mmol) were weighed in a molar ratio of 1:0.3:0.8. Under the protection of nitrogen, the mixture of the two was dissolved in dry DMAC (N,N-dimethylacetamide, 21.713 g), heated and stirred to prepare a solution with a solid content of 5%, cooled to room temperature, added Organic polymer cross-linking agent C ₉ (121.6 mg, 0.8 mmol), stirred for 2 hours, stirred evenly, filtered, filtered off insolubles, the filtrate was degassed and cast onto a 10cm×10cm glass plate, and then placed on Dry at 80°C for two hours in a forced air oven, then further heat up to 120°C and dry for one hour, and finally heat up to 240°C and dry for one hour to obtain an organic phosphonic acid high temperature proton exchange membrane. The thickness of the film is 30 μm (micrometer), the DSC test shows its glass transition temperature T _g =350°C, and the mechanical property test shows that its tensile strength is 116 MPa.

Example 10

Preparation of Composite Films of S-PBI with [2-vinylbenzimidazole-allylphosphonic acid bis(triethylsilyl)ester] copolymer B ₁₀ and organic polymer cross-linking agent C ₁₀

(1) Preparation of 2-vinylbenzimidazole-allylphosphonic acid bis(triethylsilyl)ester copolymer B10 (molar ratio 1:10)

Under nitrogen protection, 2-vinylbenzimidazole (144.2 mg, 1 mmol) and vinylphosphonic acid bis(trimethylsilyl) ester (3501.9 mg, 10 mmol) were successively added to the three-necked reaction flask, and deionized water ( 250 mL) as a solvent, and then the radical chain initiator azobisisobutyronitrile (AIBN, 9.1 mg, 0.055 mmol) was added. Stir (mechanical stirring), heat to 80°C to react. After 24 hours of reaction, the solution became viscous, the reaction was stopped, and it was cooled to room temperature. The reaction solution was poured into ethyl acetate and stirred continuously, and a solid was precipitated, which was filtered and dried in vacuo to obtain copolymer B ₁₀ .

(2) Preparation of composite film of S-PBI with copolymer B ₁₀ and organic polymer cross-linking agent C ₁₀ (molar ratio 1:10:2)

Dry S-PBI (41.6 mg, 0.1 mmol) and copolymer B ₁₀ (3645.9 mg, 1 mmol) were weighed in a molar ratio of 1:10:2. Under the protection of nitrogen, the mixture of the two was dissolved in dry DMAC (N,N-dimethylacetamide, 72.009g), heated and stirred to prepare a solution with a solid content of 5%, cooled to room temperature, added Organic polymer cross-linking agent C ₁₀ (30.4 mg, 0.2 mmol), stirred for 2 hours, stirred evenly, filtered, filtered off insolubles, the filtrate was degassed and cast onto a 10cm×10cm glass plate, and then placed on Dry at 80°C for two hours in a forced air oven, then further heat up to 120°C and dry for one hour, and finally heat up to 240°C and dry for one hour to obtain an organic phosphonic acid high temperature proton exchange membrane. The thickness of the film is 36 μm (micrometer), the DSC test shows that its glass transition temperature T _g =369° C., and the mechanical property test shows that its tensile strength is 128 MPa.

Example 11

Preparation of ABPBI and [5-vinyltriazole-tetramethyl 1,1-vinyldiphosphonate] copolymer B ₁₁ and organic polymer cross-linking agent C ₉ composite film

(1) Preparation of 5-vinyltriazole-tetramethyl 1,1-vinyldiphosphonate] copolymer B11 (molar ratio 1:12)

Under nitrogen protection, 5-vinyl triazole (95.1 mg, 1 mmol) and tetramethyl 1,1-vinyl diphosphonate (2929.4 mg, 12 mmol) were successively added to the three-necked reaction flask, and deionized water ( 250 mL) as a solvent, and then the radical chain initiator azobisisobutyronitrile (AIBN, 10.7 mg, 0.065 mmol) was added. Stir (mechanical stirring), heat to 80°C to react. After 24 hours of reaction, the solution became viscous, the reaction was stopped, and it was cooled to room temperature. The reaction solution was poured into ethyl acetate and stirred continuously, and a solid was precipitated, which was filtered and dried in vacuo to obtain copolymer B ₁₁ .

(2) Preparation of composite film of ABPBI, copolymer B ₁₁ and organic polymer cross-linking agent C ₉ (molar ratio 1:10:3)

Dry ABPBI (11.6 mg, 0.1 mmol) and copolymer B ₁₁ (3023.4 mg, 1 mmol) were weighed in a molar ratio of 1:10:3. Under the protection of nitrogen, the mixture of the two was dissolved in dry DMAC (N,N-dimethylacetamide, 27.315g), heated and stirred to prepare a solution with a solid content of 10%, cooled to room temperature, added Add organic polymer cross-linking agent C ₉ (45.6 mg, 0.3 mmol), stir for 2 hours, stir evenly, filter, filter out insoluble matter, and cast the filtrate on a 10cm×10cm glass plate after degassing. Dry in a blast oven at 80°C for two hours, then further heat up to 120°C and dry for one hour, and finally heat up to 230°C and dry for one hour to obtain an organic phosphonic acid high temperature proton exchange membrane. The thickness of the film is 31 μm (micrometer), the DSC test shows that its glass transition temperature is T _g =290°C, and the mechanical property test shows that its tensile strength is 103 MPa.

Example 12

Poly[2,6-(p-phenylene)-benzodiimidazole] and [5-vinylpyrimidine-2-propenyl[2-methylenephosphonic acid bis(trimethylsilyl) ester]phosphonic acid bis Preparation of (trimethylsilyl)ester]] copolymer B ₁₂ and organic polymer cross-linking agent C ₇ composite membrane

(1) 5-vinylpyrimidine-2-propenyl [2-methylenephosphonic acid bis(trimethylsilyl) ester]phosphonic acid bis(trimethylsilyl) ester] copolymer B ₁₂ (molar ratio 1: 16) Preparation

Under nitrogen protection, 5-vinylpyrimidine (159.2 mg, 1.0 mmol) and 2-propenyl[2-methylenephosphonic acid bis(trimethylsilyl) ester]phosphonic acid bis( Trimethylsilyl) ester (8066.5 mg, 16 mmol) in deionized water (250 mL) as solvent followed by the addition of free radical chain initiator azobisisobutyronitrile (AIBN, 14.0 mg, 0.085 mmol). Stir (mechanical stirring), heat to 80°C to react. After 24 hours of reaction, the solution became viscous, the reaction was stopped, and it was cooled to room temperature. The reaction solution was poured into ethyl acetate and stirred continuously, and a solid was precipitated, which was filtered and dried in vacuo to obtain copolymer B ₁₂ .

(2) Preparation of composite film of poly[2,6-(p-phenylene)-benzodiimidazole], copolymer B ₁₂ and organic polymer cross-linking agent C ₇ (molar ratio 1:16:10)

According to the molar ratio of 1:16:10, weigh dry poly[2,6-(p-phenylene)-benzodiimidazole] (11.6 mg, 0.05 mmol) and copolymer B ₁₂ (6538.0 mg, 0.8 mmol) ). Under the protection of nitrogen, the mixture of the two was dissolved in dry DMAC (N,N-dimethylacetamide, 26.298g), heated and stirred to prepare a solution with a solid content of 20%, cooled to room temperature, added Organic polymer cross-linking agent C ₇ (94.0 mg, 0.5 mmol), stirred for 2 hours, stirred evenly, filtered, filtered off insolubles, the filtrate was degassed and cast on a 10cm×10cm glass plate, and then placed on Dry at 80°C for two hours in a forced air oven, then further heat up to 120°C and dry for one hour, and finally heat up to 230°C and dry for one hour to obtain an organic phosphonic acid high temperature proton exchange membrane. The thickness of the film is 36 μm (micrometer), the DSC test shows that its glass transition temperature is T _g =275°C, and the mechanical property test shows that its tensile strength is 95 MPa.

Example 13

Poly[2,6-[4',4"-(diphenylsulfone)]-benzodiimidazole] and (4-vinylpyridine-vinylphosphonic acid) copolymer B ₁₃ and organic polymer cross Preparation of Joint Agent C ₁ Composite Film

(1) Preparation of 4-vinylpyridine-vinylphosphonic acid copolymer B ₁₃ (molar ratio 1:4)

Under nitrogen protection, 4-vinylpyridine (210.0 mg, 2.0 mmol) and vinylphosphonic acid (864.0 mg, 8 mmol) were successively added to the three-necked reaction flask, deionized water (250 mL) was used as a solvent, and then free radicals were added. Chain initiator azobisisobutyronitrile (AIBN, 14.8 mg, 0.09 mmol). Stir (mechanical stirring), heat to 80°C to react. After 24 hours of reaction, the solution became viscous, the reaction was stopped, and it was cooled to room temperature. The reaction solution was poured into ethyl acetate and stirred continuously, and a solid was precipitated, which was filtered and dried in vacuo to obtain copolymer B ₁₃ .

(2) Poly[2,6-[4′,4″-(diphenylsulfone)]-benzodiimidazole] with copolymer B ₁₃ and organic polymer cross-linking agent C ₁ (molar ratio 1: 4:1) Preparation of composite membrane

According to the molar ratio of 1:4:1, weigh dry poly[2,6-(p-phenylene)-benzodiimidazole] (74.4 mg, 0.2 mmol) and copolymer B ₁₃ (429.6 mg, 0.8 mmol) ). Under the protection of nitrogen, the mixture of the two was dissolved in dry DMSO (dimethyl sulfoxide, 9.576g), stirred and stirred to prepare a solution with a solid content of 5%, cooled to room temperature, and an organic polymer compound was added. Joint agent C ₁ (104.8 mg, 0.2 mmol), stirred for 2 hours, stirred evenly, filtered, and filtered off insolubles, the filtrate was degassed and cast onto a 10cm×10cm glass plate, and then placed in a blast oven Dry at 80°C for two hours, then further heat up to 120°C and dry for one hour, and finally heat up to 160°C and dry for one hour to obtain an organic phosphonic acid high temperature proton exchange membrane. The thickness of the film is 24 μm (micrometer), the DSC test shows that its glass transition temperature is T _g =288°C, and the mechanical property test shows that its tensile strength is 104 MPa.

Example 14

Poly[2,6-[4′,4″-(diphenylether)]-benzodiimidazole] and (N-vinylimidazole-vinylphosphonic acid) copolymer B ₁₄ and organic polymer cross-linking Preparation _of Agent C3 Composite Films

(1) Preparation of N-vinylimidazole-vinylphosphonic acid copolymer B ₁₄ (molar ratio 1:5)

Under nitrogen protection, N-vinylimidazole (188.0 mg, 2.0 mmol) and vinylphosphonic acid (1080.0 mg, 10 mmol) were successively added to the three-necked reaction flask, deionized water (250 mL) was used as a solvent, and then free radicals were added. Chain initiator azobisisobutyronitrile (AIBN, 19.7 mg, 0.12 mmol). Stir (mechanical stirring), heat to 80°C to react. After 24 hours of reaction, the solution became viscous, the reaction was stopped, and it was cooled to room temperature. The reaction solution was poured into ethyl acetate and stirred continuously, and a solid was precipitated, which was filtered and dried in vacuo to obtain copolymer B ₁₄ .

(2) Poly[2,6-[4′,4″-(diphenylether)]-benzodiimidazole] with copolymer B ₁₄ and organic polymer cross-linking agent C ₃ (molar ratio 1:2 : 0.1) Preparation of composite membrane

According to the molar ratio of 1:2:0.1, weigh dry poly[2,6-(p-phenylene)-benzodiimidazole] (162.2 mg, 0.5 mmol) and copolymer B ₁₄ (634.0 mg, 1.0 mmol) ). Under the protection of nitrogen, the mixture of the two was dissolved in dry DMSO (dimethyl sulfoxide, 15.128 g) to prepare a solution with a solid content of 5%, cooled to room temperature, and an organic polymer cross-linking agent was added. C ₃ (30.0 mg, 0.05 mmol), stirred for 2 hours, stirred evenly, filtered, and filtered off insolubles, the filtrate was degassed and cast onto a 10 cm×10 cm glass plate, and then placed in a blast oven at 80 Drying at ℃ for two hours, then further heating to 120 ℃ and drying for 1 hour, and finally heating to 160 ℃ and drying for 1 hour to obtain an organic phosphonic acid high temperature proton exchange membrane. The thickness of the film is 27 μm (micrometer), the DSC test shows its glass transition temperature T _g =279°C, and the mechanical property test shows that its tensile strength is 106MPa.

Example 15

Poly[2,2'-(2",6"-pyridylene)-5,5'-bis(benzimidazolyl)sulfone] and [1-vinyltriazole-allylphosphonic acid copolymer Preparation of B ₁₅ and Organic Polymer Cross-linking Agent C ₅ Composite Films

(1) Preparation of 1-vinyltriazole-allylphosphonic acid copolymer B ₁₅ (mol ratio 1:5)

Under nitrogen protection, N-vinylimidazole (190.1 mg, 2.0 mmol) and allylphosphonic acid (1220.0 mg, 10 mmol) were sequentially added to the three-necked reaction flask, deionized water (250 mL) was used as a solvent, and then free Base chain initiator azobisisobutyronitrile (AIBN, 19.7 mg, 0.12 mmol). Stir (mechanical stirring), heat to 80°C to react. After 24 hours of reaction, the solution became viscous, the reaction was stopped, and it was cooled to room temperature. The reaction solution was poured into ethyl acetate and stirred continuously, and a solid was precipitated, which was filtered and dried in vacuo to obtain copolymer B ₁₅ .

(2) Poly[2,2'-(2",6"-pyridinyl)-5,5'-bis(benzimidazolyl)sulfone] and copolymer B ₁₅ (molar ratio 1:4:0.4) Preparation of composite membranes

According to the molar ratio of 1:4:0.4, weigh dry poly[2,2'-(2",6"-pyridinyl)-5,5'-bis(benzimidazolyl)sulfone] (93.3 mg , 0.25 mmol) with copolymer B ₁₅ (705.1 mg, 1.0 mmol). Under the protection of nitrogen, the mixture of the two was dissolved in dry DMSO (dimethyl sulfoxide, 15.170 g) to prepare a solution with a solid content of 5%, cooled to room temperature, and an organic polymer cross-linking agent was added. C ₅ (66.4 mg, 0.1 mmol), stirred for 2 hours, stirred evenly, filtered, and filtered off the insolubles, the filtrate was degassed and cast onto a 10cm×10cm glass plate, and then placed in a blast oven at 80 Drying at ℃ for two hours, then further heating to 120 ℃ and drying for 1 hour, and finally heating to 160 ℃ and drying for 1 hour to obtain an organic phosphonic acid high temperature proton exchange membrane. The thickness of the film is 29 μm (micrometer), the DSC test shows that its glass transition temperature is T _g =288°C, and the mechanical property test shows that its tensile strength is 107 MPa.

Example 16

Poly[2,6-[4',4"-(diphenylmethane)]-benzodiimidazole] and [5-vinyltriazole-1,1-vinyldiphosphonic acid] copolymer B ₁₆ and the preparation of organic polymer cross-linking agent C ₁₀ composite membrane

(1) Preparation of 5-vinyltriazole-1,1-vinyldiphosphonic acid copolymer B ₁₆ (molar ratio 1:4)

Under nitrogen protection, 5-vinyl triazole (95.1 mg, 1 mmol) and 1,1-vinyl diphosphonic acid (751.9 mg, 4 mmol) were successively added to the three-necked reaction flask, and deionized water (180 mL) was used as solvent, and then the free radical chain initiator azobisisobutyronitrile (AIBN, 8.2 mg, 0.05 mmol) was added. Stir (mechanical stirring), heat to 80°C to react. After 24 hours of reaction, the solution became viscous, the reaction was stopped, and it was cooled to room temperature. The reaction solution was poured into ethyl acetate and stirred continuously, and a solid was precipitated, which was filtered and dried in vacuo to obtain copolymer B ₁₆ .

(2) Poly[2,6-[4′,4″-(diphenylmethane)]-benzodiimidazole] with copolymer B ₁₆ and organic polymer cross-linking agent C ₁₀ (molar ratio 1:3 :2) Preparation of composite membrane

According to the molar ratio of 1:3:2, weigh the dried poly[2,6-[4′,4″-(diphenylmethane)]-benzodiimidazole] (80.6 mg, 0.25 mmol) and the copolymer Compound B ₁₆ (635.3 mg, 0.75 mmol). Under the protection of nitrogen, the mixture of the two was dissolved in dry DMSO (dimethyl sulfoxide, 13.602 g) to prepare a solution with a solid content of 5%, Cool to room temperature, add organic polymer cross-linking agent C ₁₀ (76.0 mg, 0.5 mmol), stir for 2 hours, stir evenly, filter, filter out insoluble matter, and cast the filtrate to a 10cm×10cm glass plate after degassing Then put it in a forced air oven to dry at 80 ° C for two hours, then further heat up to 120 ° C and dry for one hour, and finally heat up to 160 ° C and dry for one hour to obtain an organic phosphonic acid high temperature proton exchange membrane. The thickness is 25 μm (micrometer), the DSC test shows that its glass transition temperature is T _g =297°C, and the mechanical property test shows that its tensile strength is 102MPa.

Test Example

Proton Conductivity Test:

Using the Membrane Test System 740 device, the two-electrode method was used to test the PBI film and the No. 2 film (Example 2), No. 4 film (Example 4), No. 6 film (Example 6), No. 7 film (Example 7) in this patent. Example 7), No. 9 membrane (Example 9), No. 13 membrane (Example 13), No. 14 membrane (Example 14), No. 15 membrane (Example 15) Proton conductivity test.

testing method:

(1) Pre-test treatment:

Under the condition of 60°C, the PBI film was soaked in 85% phosphoric acid, and after soaking for 48 hours, it was taken out and dried for testing.

Soak the organic phosphonic acid film to be tested in 0.5mol/L dilute phosphoric acid, soak it for 48 hours, take it out, then soak it with deionization, wash it with water until it becomes neutral (the eluate is neutral), dry it, and wait for the test.

(2) Formal test (test equipment Membrane Test System 740):

1. Cut the sample film to be tested in the shape of 1cm×3cm;

2. Use conductive adhesive to glue the GDE with Pt/C catalyst on the metal sheets of the two-electrode fixture, one on the bottom and one on the bottom, and install the cut film to be measured in the middle of the GDE, and clamp the fixture;

3. Turn on the power of the MTS 740, and put the fixture containing the film to be tested into the test chamber of the device.

4. Open the test program of the instrument and connect the pipeline connecting the gas cylinder to the instrument. Adjust the pressure of the N2 line to 0.5MPa and the pressure of the H2 line to 0.4MPa. In the inspection program, the indicator light indicates normal, and check the connection between the chemical workstation and the 740 operating chamber.

5. When the film sample starts to test, it should be purged with N2 for 10min to remove the air in the chamber. The purge speed is 500sccm/min. When the acid film is set to 100% relative humidity), after reaching the set value and stable, the test can be started.

6. Use the MTS740 program to automatically obtain the impedance spectrum, and obtain the membrane resistance value R from the spectrum.

7. Data processing: The conductivity is calculated by ρ=L/(Rs×A).

L: film thickness;

Rs: Membrane resistance read by impedance spectroscopy

A: Measured area

8. At the end of the test, it must be purged with N2 for 15 minutes to remove the water vapor in the instrument, and finally the program and the power of the instrument are turned off.

The test results are shown in Figure 1. The results show that the electrical conductivity of the composite organic phosphonic acid high temperature proton exchange membrane for fuel cells of the present application reaches the same order of magnitude as that of the PBI membrane/inorganic phosphoric acid system, and the electrical conductivity of some ratio membranes is significantly higher than that of the PBI membrane. At present, the biggest problem of the organic phosphonic acid membranes reported in large numbers is the low proton conductivity, which is 1-2 orders of magnitude lower than that of the PBI membrane/inorganic phosphoric acid system. Compared with the inorganic phosphoric acid system, it can reach the same order of magnitude and has an extremely excellent effect.

Phosphoric acid (phosphonic acid) loss rate test:

We used the PBI membrane/inorganic phosphoric acid system, and the change in conductivity of the organic phosphonic acid membrane after soaking in deionized water to reflect the phosphoric acid (phosphonic acid) loss rate. We choose PBI film/inorganic phosphoric acid, and organic phosphonic acid No. 2 film (Example 2), No. 6 film (Example 6), No. 7 film (Example 7), No. 15 film (Example 15) for test comparison :

testing method:

(1) Preparation of the test sample film for testing:

The PBI film was soaked in 85% phosphoric acid at 60°C for 48 hours and then taken out to dry.

Soak the organic phosphonic acid film to be tested in 0.5mol/L dilute phosphoric acid, soak it for 48 hours, take it out, then soak it with deionization, wash it with water until it becomes neutral (the eluate is neutral), and dry.

(2) Formal test

1. Soak the prepared sample film in deionized water for 5 minutes, then take it out and dry it.

2. Test the proton conductivity of the dried sample film at 160°C according to the previous conductivity test method (test conditions: PBI film relative humidity 2%; organic phosphonic acid film relative humidity 100%)

3. Repeat the above operations 1 and 2 for nine times.

The test results are shown in Figure 2. The proton conductivity of the PBI membrane/inorganic phosphoric acid system decreases very quickly, while the proton conductivity of the organic phosphonic acid membrane hardly decreases. This result shows that the loss of inorganic phosphoric acid in the PBI film/inorganic phosphoric acid system is very serious, while the organic phosphonic acid of the organic phosphonic acid film of the present application hardly has the problem of phosphoric acid loss. In the actual use process, the fuel cell will generate water during operation, and the proton conductivity membrane is in a state of constant water loss, while the organic phosphonic acid membrane of the present application does not have the problem of phosphonic acid being taken away with the water loss, so it is The content of phosphonic acid can be effectively stabilized in the actual use state, and then good electrical conductivity can be maintained.

Single battery discharge performance test:

Using the Fuel Cell Test System 850e device, the discharge performance of the single cells assembled with the No. 1 film (Example 1), No. 2 film (Example 2), and No. 14 film (Example 14) in this patent was tested.

(1) Preparation of the test sample film for testing:

Soak the organic phosphonic acid film to be tested in 0.5mol/L dilute phosphoric acid, soak it for 48 hours, take it out, then soak it with deionization, wash it with water until it becomes neutral (the eluate is neutral), and dry.

(2) Single battery assembly:

a) Prepare the membrane and electrode to be tested to obtain a membrane electrode, and assemble it into a single cell model for testing;

b) The single cell is connected to the Fuel Cell Test System 850e of the hydrogen fuel cell. The hydrogen inlet end is connected to the negative electrode of the battery, the air inlet end is connected to the positive electrode of the battery, and the hydrogen and air inlet and outlet ends are respectively on the same side of the graphite bipolar plate, ensuring that one gas in and one out in one bipolar plate;

(3) Single battery test:

a) Test system parameter settings:

Test temperature: 160℃

Hydrogen intake volume: 500cc/min, the metering ratio is 1.6

Air intake volume: 1500cc/min, the metering ratio is 1.3

b) Test procedure:

Using sweep potential test method

Voltage range: 0.25-1V, one data point is collected every 0.05V

c) Collect data of parameters such as voltage, current density, energy density, etc., and set the storage path;

The test results are shown in Figure 3, indicating that the organic phosphonic acid high temperature proton exchange membrane has excellent discharge performance.

Single battery working stability test:

We choose PBI film and No. 1 film (Example 1), No. 4 film (Example 4) and No. 15 film (Example 15) to assemble single cells respectively, and conduct work stability test.

1. Pre-test membrane treatment:

a) Under the condition of 60℃, soak the PBI film in 85% phosphoric acid, soak it for 48 hours and then take it out to dry. Soak the organic phosphonic acid film in 0.5 mol/L dilute phosphoric acid, take it out after soaking for 48 hours, then soak it with deionization, wash it with water until it becomes neutral (the eluate is neutral), and dry.

b) Cut the film to be tested into a size of 6.5cm×6.5cm;

2. MEA (membrane electrode) preparation;

a) Use GDL of SIGRACET company model 29BC, cut into 5×5cm size, to prepare for catalyst spraying;

b) spraying the catalyst on the pore layer of the GDL, the loading of the cathode catalyst is 2 mg/cm ² , and the loading amount of the anode catalyst is 3 mg/cm ² to prepare GDE;

c) Place the membrane to be tested in the middle, and place the cathode and anode of GDE on the top and bottom of the membrane to form a sandwich structure, and then perform hot pressing (the hot pressing conditions are 135°C, 10MPa, 2min) to obtain MEA;

3. Battery assembly:

The prepared MEAs were assembled in a single cell model.

4. Single battery test:

Test Equipment:Fuel Cell Test System 850e

Connect the single cell to the test equipment, and follow the set parameters: anode: hydrogen 500 ml/min; cathode: air 1500 ml/min; test temperature: 160 °C; PBI film relative humidity: 2%, organic phosphonic acid film relative humidity: 2% Humidity 100%, constant scanning voltage 0.7v. The instrument automatically records current density data under test conditions. The test results are shown in Figure 4.

It can be seen from the test results that the single cell assembled with PBI film can see obvious performance decline after more than 1000 hours of testing, while the No. 1 film (Example 1), No. 4 film (Example 4) and No. 15 film (Example 15) The performance of the assembled single cell has been very stable, and there is no obvious decline, indicating that the single cell prepared by the organic phosphonic acid proton exchange membrane of the present application has achieved better stability.

All documents mentioned herein are incorporated by reference in this application as if each document were individually incorporated by reference. In addition, it should be understood that after reading the above teaching content of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

Claims (9)

1. An organic polymer crosslinked organic phosphonic acid high-temperature proton exchange membrane is characterized in that the organic polymer crosslinked organic phosphonic acid high-temperature proton exchange membrane is formed by compounding (a) a polybenzimidazole type compound A, (B) an acid-base type organic phosphonic acid polymer B and (C) an organic polymer crosslinking agent C as raw materials, wherein the molar ratio nA to nB is 1: 0.01-99.99;

the acid-base organic phosphonic acid polymer B is a copolymer formed by copolymerizing a basic olefin monomer D and an organic phosphonic acid monomer E, wherein the basic olefin monomer D is selected from the following group:

wherein the organophosphonic acid monomer E is selected from the group consisting of:

R²selected from the group consisting of: H. substituted or unsubstituted C1-C9 alkyl, phenyl, trimethylsilyl, triethylsilyl, tert-butyldimethylsilyl, triisopropylsilyl,Tert-butyl diphenyl silyl; the molar ratio of monomer D to monomer E is nD: nE ═ 1: 0.01-99.99;

and the organic polymer cross-linking agent C is selected from the following groups:

wherein m is 2-10000.

2. The organic polymer crosslinked organophosphonic acid high temperature proton exchange membrane according to claim 1, wherein the polybenzimidazole polymer a is selected from the group consisting of:

wherein n is 2-10000;

r is selected from the group consisting of: chemical bond, O, S, NH, C (O), S (O)₂Unsubstituted or halogenated C1-C6 alkylene, unsubstituted or halogenated C2-C6 alkenylene;

R¹selected from the group consisting of:

3. the organic polymer crosslinked organophosphonic acid high temperature proton exchange membrane according to claim 1 wherein the polybenzimidazole type compound a is selected from the group consisting of:

wherein R is¹Is as defined in claim 2.

4. The organic polymer crosslinked organophosphonic acid high temperature proton exchange membrane according to claim 1 wherein the molar ratio of a to C, nA: nC, is 1: 0.01-10.00.

5. The organic polymer crosslinked organophosphonic acid high temperature proton exchange membrane according to claim 1, wherein the "acid-base" organophosphonic acid polymer B is prepared by the following method: and (3) carrying out polymerization reaction on the monomer D and the organic phosphonic acid monomer E in deionized water to obtain the polymer B.

6. The organic polymer crosslinked organophosphonic acid high temperature proton exchange membrane according to claim 1, wherein the molar ratio of A to B nA: nB is 1:0.1-40, and the molar ratio of A to C nC is 1: 0.02-10.00.

7. The method for preparing the organic polymer crosslinked organic phosphonic acid high-temperature proton exchange membrane according to claim 1, wherein the method for preparing the organic polymer crosslinked organic phosphonic acid high-temperature proton exchange membrane comprises the following steps:

(i) providing a polybenzimidazole type compound A and an acid-base type organic phosphonic acid polymer B;

(ii) under the protection of inert gas, dissolving the mixture of the two in an organic solvent to prepare a mixed solution;

(iii) cooling the mixed solution to room temperature, adding the organic polymer cross-linking agent C, stirring for two hours, and uniformly stirring;

(iv) filtering to remove insoluble substances to obtain mixed filtrate;

(v) degassing the mixed filtrate;

(vi) and (3) forming a membrane from the mixed filtrate subjected to degassing treatment to obtain the organic polymer crosslinked organic phosphonic acid high-temperature proton exchange membrane.

8. The process according to claim 7, wherein the molar ratio of polybenzimidazole-type compound A to "acid-base" organophosphonic acid polymer B is 1:0.1-40, wherein the molar ratio of the polybenzimidazole compound A to the organic polymer cross-linking agent C is 1: 0.02-10.00.

9. The process of claim 7, wherein in step (ii), the solution is prepared at a solids content of 1-30 wt%.

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