TWI549937B - Tetraamino-diphenyl ether, polybenzimidazole, proton exchange membrane including polybenzimidazole, and fuel cell including the proton exchange membrane - Google Patents

Description

Tetraaminodiphenyl ether, polybenzimidazole, proton exchange membrane including polybenzimidazole, and Fuel cell for this proton exchange membrane

The present invention relates to a monomer, a polymer produced using the monomer, a proton exchange membrane produced using the polymer, and a fuel cell including the proton exchange membrane, and particularly related to a novel tetraamine A diphenylene ether, a polybenzimidazole obtained by using the tetraaminodiphenyl ether, a proton exchange membrane obtained by using the polybenzimidazole, and a fuel cell including the proton exchange membrane.

In a Proton Exchange Membrane Fuel Cell (PEMFC), a proton exchange membrane as a solid electrolyte is one of the important components. Polybenzimidazoles (PBI) are widely used in the use of phosphoric acid as protons because of their excellent thermal stability, chemical stability and mechanical properties, and their high proton conductivity at high temperatures after doping with phosphoric acid. Medium high temperature proton exchange membrane fuel cells.

In order to prepare a polybenzimidazole film which can be applied to a proton exchange membrane fuel cell, the polybenzimidazole usually has to have a sufficiently large molecular weight to have good mechanical strength. However, during film formation, high molecular weight polybenzimidazole such as low solubility in N, N - dimethylacetamide (dimethylacetamide, DMAc) and the like solvents, and therefore need to use a special film formation conditions (such as oxygen-free , pressurization and high temperature, etc., or the structure of polybenzimidazole is modified in advance to achieve the purpose of improving solubility. As a result, the complexity and production cost of using polybenzimidazole are increased, and the processability of polybenzimidazole is limited.

The present invention provides a novel tetraaminodiphenyl ether, a polybenzimidazole prepared by using the tetraaminodiphenyl ether, a proton exchange membrane obtained by using the polybenzimidazole, and a fuel including the proton exchange membrane A battery in which the proton exchange membrane produced has good stability and mechanical strength.

The tetraaminodiphenyl ether of the present invention has the following formula (1): Wherein X in the formula (1) is a halogen, an alkyl group, a haloalkyl group or a group containing an aromatic ring.

In an embodiment of the invention, the above X is fluorine, chlorine, bromine, iodine, methyl, trifluoromethyl, , or .

In an embodiment of the invention, the above tetraaminodiphenyl ether has the following formula (2):

In an embodiment of the invention, the above tetraaminodiphenyl ether is represented by the following formula (3): Wherein Y in the formula (3) is hydrogen or a haloalkyl group.

The polybenzimidazole of the present invention, which is derived from the aforementioned tetraaminodiphenyl ether and (4) The diacid shown is obtained by carrying out a polymerization reaction as a monomer, and the polybenzimidazole is represented by the following formula (5): HOOC-R-COOH formula (4)

Wherein X in the formula (5) is a halogen, an alkyl group, a haloalkyl group or a group containing an aromatic ring.

In an embodiment of the invention, R in the above formula (4) is a group containing an aromatic ring.

In an embodiment of the invention, R in the above formula (4) is

In an embodiment of the invention, the polybenzimidazole is represented by the following formula (6), formula (7) or formula (8):

The proton exchange membrane of the present invention is formed of the aforementioned polybenzimidazole doped with phosphoric acid.

The fuel cell of the present invention comprises an anode catalyst layer, a cathode catalyst layer and the foregoing Sub-exchange membrane. The proton exchange membrane is disposed between the anode catalyst layer and the cathode catalyst layer.

Based on the above, the technical features of the present invention include a novel tetraaminodiphenyl ether, a novel polybenzimidazole prepared by using the tetraaminodiphenyl ether, a proton exchange membrane obtained by using the polybenzimidazole, and the like This proton exchange membrane fuel cell. The novel polybenzimidazole has good solubility, thereby improving the processability of polybenzimidazole and improving its applicability. In addition, the proton exchange membrane produced by the novel polybenzimidazole has high mechanical strength, thermal stability, oxidative stability and proton conductivity, and thus the fuel cell using the same has good battery efficiency.

The above described features and advantages of the invention will be apparent from the following description.

100‧‧‧ fuel cell

110‧‧‧First fuel diffusion layer

120‧‧‧Anode catalyst layer

130‧‧‧Proton exchange membrane

140‧‧‧ Cathode catalyst layer

150‧‧‧Second fuel diffusion layer

1 is a synthetic route of tetraaminodiphenyl ether according to an embodiment of the present invention.

Fig. 2 and Fig. 3 respectively show a ¹ H-NMR nuclear magnetic resonance spectrum and a mass spectrum of 4,4',5,5'-tetraamino-2,2'-dibromodiphenyl ether.

Fig. 4 and Fig. 5 respectively show a ¹ H-NMR nuclear magnetic resonance spectrum and a mass spectrum of 4,4'-5,5'-tetraamino-2,2'-diphenyldiphenyl ether.

Figure 6 and Figure 7 respectively show ¹ H- of 4,4'-5,5'-tetraamino-2,2'-bis[3,5-bis(trifluoromethyl)phenyl]diphenyl ether. NMR nuclear magnetic resonance spectrum schematic and mass spectrum.

Figure 8 is a synthetic route of polybenzimidazole according to an embodiment of the present invention.

Figure 9 is a view showing the results of oxidation stability of polybenzimidazole according to an embodiment of the present invention. Figure.

Figure 10 is a schematic illustration of a fuel cell in accordance with an embodiment of the present invention.

Figure 11 is a diagram showing the results of characteristics of a single cell according to an embodiment of the present invention.

Hereinafter, the novel tetraaminodiphenyl ether of the present invention, a novel polybenzimidazole prepared by using the tetraaminodiphenyl ether, a proton exchange membrane obtained by using the polybenzimidazole, and the like will be described in detail. Proton exchange membrane fuel cell.

Tetraaminodiphenyl ether

The tetraaminodiphenyl ether of the present invention has the following formula (1): Wherein X in the formula (1) is a halogen, an alkyl group, a haloalkyl group or a group containing an aromatic ring.

In one embodiment, X is fluorine, chlorine, bromine, iodine, methyl, trifluoromethyl,

In one embodiment, when X is bromine, it is 4,4',5,5'-tetraamino-2,2'-dibromodiphenyl ether (4,4',5,5'-tetraamino- 2,2'-dibromodiphenyl ether), as expressed by the following formula (2):

In one embodiment, when X is a group containing an aromatic ring, it is represented by the following formula (3):

In one embodiment, when Y in formula (3) is hydrogen, it is 4,4',5,5'-tetraamino-2,2'-diphenyldiphenyl ether (4,4', 5,5'-tetraamino-2,2'-diphenyldiphenyl ether), as represented by the following formula (3-1):

In one embodiment, when Y in formula (3) is trifluoromethyl, which is 4,4',5,5'-tetraamino-2,2'-bis[3,5-bis (three (4,4',5,5'-tetraamino-2,2'-di[3,5-bis(trifluoromethyl)phenyl]diphenyl ether), as in the following formula (3- 2) indicates:

Next, three methods for synthesizing the tetraaminodiphenyl ether represented by the formula (1) and confirming and analyzing the chemical structure of the obtained compound will be described. Referring to Figure 1, in the following example, the intermediate product 4,4'-diethylammonium-2,2'-dibromo was prepared using 4,4'-diaminodiphenyl ether as a starting material. -5,5'-dinitrodiphenyl ether (5) , followed by 4,4'-diethylammonium-2,2'-dibromo-5,5'-dinitrodiphenyl ether (5 ) 4,4',5,5'-tetraamino-2,2'-dibromodiphenyl ether (7) , 4,4',5,5'-tetraamino-2,2' -diphenyldiphenyl ether (10) and 4,4',5,5'-tetraamino-2,2'-bis[3,5-bis(trifluoromethyl)phenyl]diphenyl ether ( 13) .

Preparation of 4,4'-Dinitrodiphenyl ether (1)

9.00 g (45.00 mmol) of 4,4'-diaminodiphenyl ether (4,4'-oxydianiline (4,4'-ODA)), 180 ml of acetic acid, 81 ml 35% hydrogen peroxide and 3.6 ml of concentrated sulfuric acid were sequentially added to a 500 ml three-necked round bottom flask and stirred uniformly with a magnet. Next, the reaction temperature was raised to 85 ° C, and the reaction was stopped after the reaction until the solution became clear yellow. After the reaction is completed, the solution is poured into ice water and stirred while the temperature of the solution is lowered to room temperature. Next, the precipitate was collected and washed with water until neutral, and after drying, 5.73 g of a yellow solid was obtained, that is, 4,4'-dinitrodiphenyl ether. The 4,4'-dinitrodiphenyl ether had a melting point of 144-146 ° C and a yield of 49%.

Further, the obtained 4,4'-dinitrodiphenyl ether was identified by ¹ H-NMR analysis, ¹³ C-NMR analysis and electron mass spectrometry of a nuclear magnetic resonance spectrum (NMR spectrum). In the table of NMR spectra shown below, s refers to a singlet (Singlet), d refers to a doublet (Doublet), t refers to a triplet (Triplet), q refers to a quartet (Quartet), and m is Refers to multiple peaks (Multiplet).

^{1 H NMR (500MHz, DMSO- d} 6, δ, ppm): 7.37 (d, J = 9.2Hz, 4H), 8.33 (d, J = 9.2Hz, 4H).

¹³ C NMR (125 MHz, DMSO- d ₆ , δ, ppm): 119.6, 126.2, 143.7, 160.4.

The results of electron mass spectrometry of 4,4'-dinitrodiphenyl ether (C ₁₂ H ₈ N ₂ O ₅ ) of this example are as follows. The theoretical value is: 260.0. The analytical value was: 260.0.

Preparation of 2,2'-Dibromo-4,4'-dinitrodiphenyl ether (2)

10 ml of water, 200 ml of concentrated sulfuric acid, 8.00 g (30.74 mmol) of 4,4'-dinitrodiphenyl ether (1) and 11.48 g (64.50 mTorr) of N-brominated N-bromosuccinimide (NBS) was sequentially added to a 250 ml three-necked round bottom flask and stirred uniformly with a magnet. Next, the reaction temperature was raised to 85 ° C and then reacted for 6 hours. After the reaction is completed, the solution is poured into ice water and stirred while the temperature of the solution is lowered to room temperature. Next, the precipitate was collected and washed with water until neutral. The initial product was recrystallized from acetone and dried to give 8.22 g of crystals of the skin color, which was 2,2'-dibromo-4,4'-dinitrodiphenyl ether. The 2,2'-dibromo-4,4'-dinitrodiphenyl ether had a melting point of 155-158 ° C and a yield of 64%.

Further, the obtained 2,2'-dibromo-4,4'-dinitrodiphenyl ether was identified by ¹ H-NMR analysis, ¹³ C-NMR analysis and electron mass spectrometry of a nuclear magnetic resonance spectrum.

^{1 H NMR (500MHz, DMSO- d} 6, δ, ppm): 7.33 (d, J = 9.0Hz, 2H), 8.65 (d, J = 2.6Hz, 2H), 8.29 (dd, J 1 = 9.0Hz, J ₂ = 2.6 Hz, 2H).

¹³ C NMR (125 MHz, DMSO- d ₆ , δ, ppm): 113.8, 120.0, 125.3, 129.3, 144.4, 156.6.

The results of electron mass spectrometry of 2,2'-dibromo-4,4'-dinitrodiphenyl ether (C ₁₂ H ₆ Br ₂ N ₂ O ₅ ) of this example are as follows. The theoretical value is 415.9. Analytical value: 415.8.

Preparation of 2,2'-dibromo-4,4'-diaminodiphenyl ether (2,2'-Dibromo-4,4'-oxydianiline) (3)

Add 8.00 g (19.14 mmol) of 2,2'-dibromo-4,4'-dinitrodiphenyl ether ( 2 ), 178 ml of ethanol and 40 ml of 37% hydrochloric acid to 500 ml of three The flask was round and bottomed and stirred evenly with a magnet. Next, 9.38 g of tin powder was added and the temperature was raised to 80 ° C for 3 hours. After the completion of the reaction, the solution was poured into ice water while the temperature of the solution was lowered to room temperature, and the pH of the reaction solution was adjusted to 12 with a 2 molar aqueous sodium hydroxide solution. Then, the reaction solution was extracted with diethyl ether and the organic layer was collected. Then, anhydrous sodium sulfate was added to the organic layer to remove water, and then diethyl ether was removed by a vacuum concentrator. The initial product was purified by recrystallization from ethanol and dried to give 3.76 g of white crystals as 2,2'-dibromo-4,4'-diaminodiphenyl ether. The 2,2'-dibromo-4,4'-diaminodiphenyl ether had a melting point of 147-149 ° C and a yield of 55%.

Further, the obtained 2,2'-dibromo-4,4'-diaminodiphenyl ether was identified by ¹ H-NMR analysis, ¹³ C-NMR analysis and electron mass spectrometry of a nuclear magnetic resonance spectrum.

^{1 H NMR (500MHz, DMSO- d} 6, δ, ppm): 5.12 (s, 4H), 6.49 (dd, J 1 = 8.7Hz, J 2 = 2.5Hz, 2H), 6.54 (d, J = 8.7Hz , 2H), 6.84 (d, J = 2.5 Hz, 2H).

¹³ C NMR (125 MHz, DMSO- d ₆ , δ, ppm): 113.2, 114.1, 117.5, 119.8, 143.7, 145.9.

The results of electron mass spectrometry of 2,2'-dibromo-4,4'-diaminodiphenyl ether (C ₁₂ H ₁₀ Br ₂ N ₂ O) of this example are as follows. The theoretical value is: 355.9. Analytical value: 355.9.

Preparation of 4,4'-Diacetamido-2,2'-dibromodiphenyl ether (4)

After grinding 10.00 g (28.00 mmol) of 2,2'-dibromo-4,4'-diaminodiphenyl ether ( 3 ) into a powder, it was added to vigorously stirred 400 ml of acetic anhydride. The reaction was carried out at room temperature for 24 hours. After completion of the reaction, the precipitate was collected and washed with water until neutral. After drying, 12.05 g of a white solid was obtained, which was 4,4'-diethylamino-2,2'-dibromodiphenyl ether. The melting point of 4,4'-diethylamino-2,2'-dibromodiphenyl ether was 243-246 ° C, and the yield was 97%.

Further, 4,4'-dibromo-2,2'-acetylglucosamine ether is obtained ¹ H-NMR analysis and ¹³ C-NMR analysis and mass spectrometry electron NMR spectrum to be identified .

^{1 H NMR (500MHz, DMSO- d} 6, δ, ppm): 2.04 (s, 6H), 6.86 (d, J = 7.4Hz, 2H), 7.44 (dd, J 1 = 7.4Hz, J 2 = 2.1Hz , 2H), 8.07 (d, J = 2.1 Hz, 2H), 10.08 (s, 2H).

¹³ C NMR (125 MHz, DMSO- d ₆ , δ, ppm): 24.8, 113.6, 120.4, 120.6, 124.5, 137.3, 149.0, 169.3.

The results of electron mass spectrometry of 4,4'-diethylamino-2,2'-dibromodiphenyl ether (C ₁₆ H ₁₄ Br ₂ N ₂ O ₃ ) of this example are as follows. The theoretical value is 439.9. The analytical value was 439.9.

4,4'-diethylammonium-2,2'-dibromo-5,5'-dinitrodiphenyl ether (4,4'-Diacetamido-2,2'-dibromo-5,5'- preparation dinitrodiphenyl ether) (5)

The 7.04 g (15.92 mmol) of 4,4'-dibromo-diphenyl ether-2,2'-acetylglucosamine (4) and 22 ml of concentrated sulfuric acid was added 100 ml three-necked round bottom flask with stirring To the full solution. Next, the temperature was lowered to 0 to 5 ° C for 30 minutes, and then 2 ml of 65% nitric acid was slowly dropped into the dosing funnel. After the addition of nitric acid, the reaction was carried out at 0 to 5 ° C for 2 hours, followed by the reaction at room temperature for 2 hours. After the reaction was completed, the solution was poured into ice water and stirred, and then the precipitate was collected and washed with water until neutral. After drying, 8.04 g of a yellow solid was obtained, which was 4,4'-diethylamino-2,2'- Bromo-5,5'-dinitrodiphenyl ether. The 4,4'-diethylamino-2,2'-dibromo-5,5'-dinitrodiphenyl ether had a melting point of 260 to 265 ° C and a yield of 95%.

In addition, the obtained 4,4'-diethylammonium-2,2'-dibromo-5,5'-dinitrodiphenyl ether was analyzed by ¹ H-NMR and ¹³ C- of nuclear magnetic resonance spectrum. Identification was carried out by NMR analysis and electron mass spectrometry.

^{1 H NMR (500MHz, DMSO- d} 6, δ, ppm): 2.08 (s, 6H), 7.66 (s, 2H), 8.09 (s, 2H), 10.31 (s, 2H).

¹³ C NMR (125 MHz, DMSO- d ₆ , δ, ppm): 24.3, 116.5, 119.8, 129.6, 130.8, 142.6, 149.0, 169.6.

About acetylglucosamine 2,2'-dibromo-4,4'-dinitro-5,5'-diphenyl ether _{(C 16 H 12 Br 2 N} 4 O 7) according to the present embodiment of an electronic mass The analysis results are as follows. The theoretical value is 529.9. The analytical value was 529.9.

4,4'-Diamino-2,2'-dibromo-5,5'-dinitrodiphenyl ether (4,4'-Diamino-2,2'-dibromo-5,5'-dinitrodiphenyl ether (6) Preparation

6.00 g (11.27 mmol) of 4,4'-diethylamino-2,2'-dibromo-5,5'-dinitrodiphenyl ether ( 5 ), 152 ml of water and 152 A milliliter of 37% hydrochloric acid was placed in a 500 ml three-necked round bottom flask, stirred uniformly with a magnet, and then the reaction temperature was raised to 110 ° C and reacted for 24 hours. After the reaction is completed, when the temperature of the solution is lowered to room temperature, the pH of the solution is adjusted to 10 with ammonia water, and then the precipitate is collected and washed with water until neutral. After drying, 4.85 g of an orange solid is obtained, which is 4, 4'- Diamino-2,2'-dibromo-5,5'-dinitrodiphenyl ether. The melting point of 4,4'-diamino-2,2'-dibromo-5,5'-dinitrodiphenyl ether was 249-253 ° C, and the yield was 96%.

In addition, the obtained 4,4'-diamino-2,2'-dibromo-5,5'-dinitrodiphenyl ether was analyzed by ¹ H-NMR analysis and ¹³ C-NMR analysis of nuclear magnetic resonance spectrum. And electronic mass spectrometry for identification.

¹ H NMR (500 MHz, DMSO- d ₆ , δ, ppm): 7.47-7.50 (m, 8H).

¹³ C NMR (125 MHz, DMSO- d ₆ , δ, ppm): 115.1, 124.2, 124.3, 129.7, 142.5, 144.5.

Electron mass spectrometric analysis of 4,4'-diamino-2,2'-dibromo-5,5'-dinitrodiphenyl ether (C ₁₂ H ₈ Br ₂ N ₄ O ₅ ) of this example as follows. The theoretical value is 445.9. The analytical value was 445.9.

Preparation of 4,4',5,5'-Tetraamino-2,2'-dibromodiphenyl ether (7)

2.00 g (4.46 mmol) of 4,4'-diamino-2,2'-dibromo-5,5'-dinitrodiphenyl ether ( 6 ), 50 ml of ethanol/distilled water (volume The ratio of 5:1), 1 ml of a saturated aqueous solution of NH ₄ Cl and 1.5 g of iron powder were sequentially added to a 100 ml three-necked round bottom flask, stirred uniformly with a magnet and heated to 80 ° C for 3 hours. After completion of the reaction, when the temperature of the solution was lowered to room temperature, the precipitate was removed by filtration through celite, and the residue was washed with ethyl acetate. Next, the filtrate was concentrated under reduced pressure, and then extracted with ethyl acetate. The organic layer was collected, and then anhydrous sodium sulfate was added to remove water. The initial product was purified by column chromatography using ethyl acetate as a solvent. After drying, 0.82 g of a skin color solid was obtained, which was 4,4',5,5'-tetraamino-2,2'-dibromo. Diphenyl ether. The melting point of 4,4',5,5'-tetraamino-2,2'-dibromodiphenyl ether was 105-107 ° C, and the yield was 48%.

Further, the obtained 4,4 ', 5,5'-dibromo-2,2'-diphenyl ether group is ¹ H-NMR analysis and nuclear magnetic resonance spectrum ¹³ C-NMR analysis, mass spectrometry electron And elemental analysis for identification. Fig. 2 and Fig. 3 respectively show a ¹ H-NMR nuclear magnetic resonance spectrum and a mass spectrum of 4,4',5,5'-tetraamino-2,2'-dibromodiphenyl ether.

^{1 H NMR (500MHz, DMSO- d} 6, δ, ppm): 6.70 (s, 2H), 6.08 (s, 2H), 4.68 (s, 8H).

¹³ C NMR (125 MHz, DMSO- d ₆ , δ, ppm): 97.8, 105.2, 117.1, 131.9, 136.2, 145.2.

The results of electron mass spectrometry of 4,4',5,5'-tetraamino-2,2'-dibromodiphenyl ether of this example are as follows. The theoretical value is: 385.9. The analytical value was: 385.9. The elemental analysis results of 4,4',5,5'-tetraamino-2,2'-dibromodiphenyl ether (C ₁₂ H ₁₂ Br ₂ N ₄ O) were as follows. The theoretical values are: C, 37.14%; H, 3.12%; N, 14.44%. Analytical values were: C, 37.41%; H, 3.16%; N, 14.30%.

4,4'-diethylammonium-5,5'-dinitro-2,2'-diphenyldiphenyl ether (4,4'-Diacetamido-5,5'-dinitro-2,2' -diphenyldiphenyl ether) Preparation of (8)

A 500 ml three-necked round bottom flask equipped with a condenser and nitrogen inflow/outflow was installed, and 4.00 g (7.52 mmol) of 4,4'-diethylamino-2,2'-dibromo- 5,5'-Dinitrodiphenyl ether ( 5 ) and 200 ml of toluene were added thereto and heated to 80 ° C to be stirred uniformly. Next, an aqueous solution of sodium carbonate (3.50 g of sodium carbonate dissolved in 35 ml of water) and 0.55 g of tetrakis (triphenylphosphine) palladium were added, and vigorously stirred for 60 minutes, followed by addition of a boric acid ethanol solution ( 2.29 g of benzene boronic acid was dissolved in 40 ml of ethanol, followed by a reaction for 24 hours. After completion of the reaction, the precipitate was removed by filtration through celite, and the filtrate was washed several times with a saturated aqueous solution of sodium chloride, and then water was evaporated over anhydrous magnesium sulfate. The initial product was purified by column chromatography using dichloromethane as a solvent to give 2.37 g of a yellow solid, which was 4,4'-diethylamino-5,5'-dinitro-2,2 '-Diphenyldiphenyl ether. The 4,4'-diethylammonium-5,5'-dinitro-2,2'-diphenyldiphenyl ether had a melting point of 189 to 191 ° C and a yield of 60%.

In addition, the obtained 4,4'-diethylammonium-5,5'-dinitro-2,2'-diphenyldiphenyl ether was analyzed by ¹ H-NMR and ¹³ C of nuclear magnetic resonance spectrum. - NMR analysis and electron mass spectrometry were used for identification.

^{1 H NMR (500MHz, DMSO- d} 6, δ, ppm): 2.07 (s, 6H), 7.38-7.43 (m, 10H), 7.60 (s, 2H), 7.68 (s, 2H), 10.24 (s, 2H).

¹³ C NMR (125 MHz, DMSO- d ₆ , δ, ppm): 23.3, 114.8, 127.5, 127.6, 128.4, 128.6, 128.7, 134.8, 137.6, 141.5, 148.4, 168.5.

Electronic mass spectrometric analysis of 4,4'-diethylammonium-5,5'-dinitro-2,2'-diphenyldiphenyl ether (C ₂₈ H ₂₂ N ₄ O ₇ ) of this example The results are as follows. The theoretical value is 526.2. Analytical value: 526.1.

4,4'-Diamino-5,5'-dinitro-2,2'-diphenyldiphenyl ether (4,4'-Diamino-5,5'-dinitro-2,2'-diphenyldiphenyl Ether) Preparation of (9)

6.00 g (11.40 mmol) of 4,4'-diethylammonium-5,5'-dinitro-2,2'-diphenyldiphenyl ether ( 8 ) and 40 ml of methanol were added. A 100 ml three-necked round bottom flask was stirred evenly with a magnet. Next, a potassium hydroxide methanol solution (2.16 g of potassium hydroxide dissolved in 10 ml of methanol) was slowly added, and then 1.20 g of potassium hydroxide was further added, and the reaction was heated to reflux for 6 hours. After the reaction is completed, the solution is poured into water and stirred while the temperature of the solution is lowered to room temperature, and the precipitate is collected and washed with water until neutral. After drying, 4.79 g of an orange solid is obtained, which is 4,4'-diamino-5,5'. -Dinitro-2,2'-diphenyldiphenyl ether. The melting point of 4,4'-diamino-5,5'-dinitro-2,2'-diphenyldiphenyl ether was 251-253 ° C, and the yield was 95%.

Further, the obtained 4,4'-diamino-5,5'-dinitro-2,2'-diphenyldiphenyl ether was subjected to ¹ H-NMR analysis and ¹³ C-NMR of nuclear magnetic resonance spectrum. Analysis and electron mass spectrometry were performed for identification.

^{1 H NMR (500MHz, DMSO- d} 6, δ, ppm): 7.06 (s, 2H), 7.33-7.40 (m, 14H), 7.45 (s, 2H).

¹³ C NMR (125 MHz, DMSO- d ₆ , δ, ppm): 113.7, 121.6, 128.8, 128.9, 129.0, 135.0, 141.9, 143.3, 143.5.

The results of electron mass spectrometry of 4,4'-diamino-5,5'-dinitro-2,2'-diphenyldiphenyl ether (C ₂₄ H ₁₈ N ₄ O ₅ ) of the present example are as follows . The theoretical value is 442.1. The analytical value was 442.1.

4,4',5,5'-Tetraamino-2,2'-diphenyldiphenyl ether (10) preparation

2.00 g (4.52 mmol) of 4,4'-diamino-5,5'-dinitro-2,2'-diphenyldiphenyl ether ( 9 ), 24 ml of ethyl acetate, 3.40 g of ammonium formate, 24 ml of ethanol and 0.40 g of 10 wt% palladium on carbon were sequentially added to a 100 ml three-necked round bottom flask, and the reaction was stirred with a magnet at room temperature for 24 hours. After completion of the reaction, the precipitate was removed by filtration through celite, and then the solvent was removed under a vacuum concentrator. Finally, the mixture was recrystallized and purified by a mixture of ethanol and water (1:1 by volume). After drying, 1.67 g of a gray solid was obtained, which was 4,4',5,5'-tetraamino-2,2'. - Diphenyldiphenyl ether. The melting point of 4,4',5,5'-tetraamino-2,2'-diphenyldiphenyl ether was 199-201 ° C, and the yield was 97%.

In addition, the obtained 4,4',5,5'-tetraamino-2,2'-diphenyldiphenyl ether was analyzed by ¹ H-NMR analysis and ¹³ C-NMR analysis of nuclear magnetic resonance spectrum, and mass spectrometry. Analysis and elemental analysis were performed for identification. Fig. 4 and Fig. 5 respectively show a ¹ H-NMR nuclear magnetic resonance spectrum and a mass spectrum of 4,4',5,5'-tetraamino-2,2'-diphenyldiphenyl ether.

^{1 H NMR (500MHz, DMSO- d} 6, δ, ppm): 4.25 (s, 4H), 4.67 (s, 4H), 6.13 (s, 2H), 6.57 (s, 2H), 7.14 (t, J = 13.0 Hz, 2H), 7.25 (t, J = 13.0 Hz, 4H), 7.37 (d, J = 6.5 Hz, 4H).

¹³ C NMR (125 MHz, DMSO- d ₆ , δ, ppm): 105.1, 115.8, 119.7, 125.4, 127.7, 128.3, 130.4, 136.4, 139.0, 146.7.

The results of electron mass spectrometry of 4,4',5,5'-tetraamino-2,2'-diphenyldiphenyl ether of this example are as follows. The theoretical value is: 382.2. Analysis values: Elemental analysis 382.1.4,4 ', 5,5'-diphenyl-2,2'-diphenyl ether group _{(C 24 H 22 N 4 O} ) is as follows. The theoretical values are: C, 75.37%; H, 5.80%; N, 14.65%. Analytical values were: C, 74.53%; H, 5.93%; N, 14.40%.

4,4'-diethylammonium-2,2'-bis[3,5-bis(trifluoromethyl)phenyl]-5,5'-dinitrodiphenyl ether (4,4'- Preparation of Diacetamido-2,2'-di[3,5-bis(trifluoromethyl)phenyl]-5,5'-dinitrodiphenyl ether) (11)

A 500 ml three-necked round bottom flask with a condenser inlet and nitrogen inflow/outflow was installed, and 4.00 g (7.52 mmol) of 4,4'-5,5'-tetraamino-2,2'-di Phenyldiphenyl ether ( 5 ) and 200 ml of toluene were added thereto, and the mixture was heated to 80 ° C and stirred well. Next, an aqueous solution of sodium carbonate (3.50 g of sodium carbonate dissolved in 35 ml of water) and 0.55 g of tetrakis(triphenylphosphine)palladium were added, and vigorously stirred for 60 minutes, followed by addition of a boric acid ethanol solution (5.00 g of 3,5-double ( Trifluoromethyl)benzeneboronic acid was dissolved in 40 ml of ethanol) and then reacted for 3 days. After completion of the reaction, the precipitate was removed by filtration through celite, and the filtrate was washed several times with a saturated aqueous solution of sodium chloride, and then water was evaporated over anhydrous magnesium sulfate. The initial product was purified by column chromatography using dichloromethane as the extract to obtain 2.10 g of a yellow solid, which was 4,4'-diethylamino-2,2'-bis[3,5-double (Trifluoromethyl)phenyl]-5,5'-dinitrodiphenyl ether. The melting point of the 4,4'-diethylamino-2,2'-bis[3,5-bis(trifluoromethyl)phenyl]-5,5'-dinitrodiphenyl ether was determined. 234 ~ 235 ° C, the yield is 35%.

Further, the obtained 4,4'-diethylammonium-2,2'-bis[3,5-bis(trifluoromethyl)phenyl]-5,5'-dinitrodiphenyl ether is Identification was carried out by ¹ H-NMR analysis and ¹³ C-NMR analysis of nuclear magnetic resonance spectrum and electron mass spectrometry.

^{1 H NMR (500MHz, DMSO- d} 6, δ, ppm): 2.10 (s, 6H), 7.81 (s, 2H), 7.89 (s, 2H), 8.09 (s, 4H), 8.17 (s, 2H) , 10.36 (s, 2H).

^{13 C NMR (125MHz, DMSO- d} 6, δ, ppm): 122.7 (Quartet, J = 225Hz, * CF 3), 130.1 (Quartet, J = 25Hz, * C-CF 3), 22.9,114.5,112.0, 127.2, 128.2, 129.3, 133.5, 136.7, 142.7, 147.8, 168.3.

Regarding 4,4'-diethylammonium-2,2'-bis[3,5-bis(trifluoromethyl)phenyl]-5,5'-dinitrodiphenyl ether (in this example) The results of electron mass spectrometry of C ₃₂ H ₁₈ F ₁₂ N ₄ O ₇ ) are as follows. The theoretical value is: 798.1. Analytical value: 798.0.

4,4'-Diamino-2,2'-bis[3,5-bis(trifluoromethyl)phenyl]-5,5'-dinitrodiphenyl ether (4,4'-Diamino-) Preparation of 2,2'-di[3,5-bis(trifluoromethyl)phenyl]-5,5'-dinitrodiphenyl ether) (12)

9.10 g (11.40 mmol) of 4,4'-diethylamino-2,2'-bis[3,5-bis(trifluoromethyl)phenyl]-5,5'-dinitrate Diphenyl ether ( 11 ) and 40 ml of methanol were placed in a 100 ml three-necked round bottom flask and stirred uniformly with a magnet. Next, a potassium hydroxide methanol solution (2.16 g of potassium hydroxide dissolved in 10 ml of methanol) was slowly added, and then 1.20 g of potassium hydroxide was further added, and the reaction was heated to reflux for 6 hours. After the reaction is completed, when the temperature of the solution is lowered to room temperature, it is poured into water and stirred, and the precipitate is collected and washed with water until neutral, and then the column layer is extracted with n-hexane and ethyl acetate (volume ratio of 5:3). Purification by analytical method gave 7.49 g of an orange solid, which was 4,4'-diamino-2,2'-bis[3,5-bis(trifluoromethyl)phenyl]-5,5'- Nitrodiphenyl ether. The melting point of the 4,4'-diamino-2,2'-bis[3,5-bis(trifluoromethyl)phenyl]-5,5'-dinitrodiphenyl ether was 110~ The yield was 92% at 112 °C.

In addition, the obtained 4,4'-diamino-2,2'-bis[3,5-bis(trifluoromethyl)phenyl]-5,5'-dinitrodiphenyl ether is a nuclear magnetic Identification was carried out by ¹ H-NMR analysis and ¹³ C-NMR analysis of resonance spectrum and electron mass spectrometry.

^{1 H NMR (500MHz, DMSO- d} 6, δ, ppm): 7.26 (s, 2H), 7.46 (s, 4H), 7.74 (s, 2H), 8.00 (s, 4H), 8.16 (s, 2H) .

¹³ C NMR (125 MHz, DMSO- d ₆ , δ, ppm): 123.2 (Quartet, J = 225 Hz, *CF ₃ ), 131.3 (Quartet, J = 25 Hz, *C-CF ₃ ), 114.5, 122.9, 123.2, 130.0, 130.1, 138.4, 138.6, 142.7, 144.0.

Regarding 4,4'-diamino-2,2'-bis[3,5-bis(trifluoromethyl)phenyl]-5,5'-dinitrodiphenyl ether (C _{28) of the present example} The results of electron mass spectrometry of H ₁₄ F ₁₂ N ₄ O ₅ ) are as follows. The theoretical value is: 714.1. Analytical value: 714.1.

4,4',5,5'-tetraamino-2,2'-bis[3,5-bis(trifluoromethyl)phenyl]diphenyl ether (4,4',5,5'-Tetraamino -2,2'-di[3,5-bis(trifluoromethyl)phenyl]diphenyl ether) (13) Preparation

3.23 g (4.52 mmol) of 4,4'-diamino-2,2'-bis[3,5-bis(trifluoromethyl)phenyl]-5,5'-dinitrodi Phenyl ether ( 12 ), 24 ml of ethyl acetate, 3.40 g of ammonium formate, 24 ml of ethanol and 0.40 g of 10 wt% palladium/carbon were sequentially added to a 100 ml three-necked round bottom flask at room temperature. The magnet was stirred for 24 hours. After completion of the reaction, the precipitate was removed by filtration through celite, and then the solvent was removed under a vacuum concentrator. Finally, ethyl acetate was used as the extract to purify by column chromatography. After drying, 2.78 g of skin color solid was obtained, which was 4,4',5,5'-tetraamino-2,2'-di[3 , 5-bis(trifluoromethyl)phenyl]diphenyl ether. 4,4',5,5'-tetraamino-2,2'-bis[3,5-bis(trifluoromethyl)phenyl]diphenyl ether has a melting point of 96-98 ° C, yield It is 94%.

Further, the obtained 4,4 ', 5,5'-amino-2,2'-bis [3,5-bis (trifluoromethyl) phenyl] ether is a NMR spectrum of ¹ Identification was carried out by H-NMR analysis and ¹³ C-NMR analysis, electron mass spectrometry, and elemental analysis. Figure 6 and Figure 7 respectively show ¹ H- of 4,4',5,5'-tetraamino-2,2'-bis[3,5-bis(trifluoromethyl)phenyl]diphenyl ether. NMR nuclear magnetic resonance spectrum schematic and mass spectrum.

^{1 H NMR (500MHz, DMSO-} d 6, δ, ppm): 4.50 (s, 4H), 5.04 (s, 4H), 6.24 (s, 2H), 6.79 (s, 2H), 7.86 (s, 2H) , 7.93 (s, 4H).

^{13 C NMR (125MHz, DMSO-} d 6, δ, ppm): 124.3 (Quartet, J = 225Hz, * CF 3), 130.9 (Quartet, J = 25Hz, * C-CF 3), 104.9,116.0,116.4, 119.5, 129.0, 132.1, 139.2, 142.0, 146.7.

The results of electron mass spectrometry of 4,4',5,5'-tetraamino-2,2'-bis[3,5-bis(trifluoromethyl)phenyl]diphenyl ether of this example are as follows. The theoretical value is: 654.1. Analytical value: 654.3. 4,4',5,5'-tetraamino-2,2'-bis[3,5-bis(trifluoromethyl)phenyl]diphenyl ether (C ₂₈ H ₁₈ F The elemental analysis results of ₁₂ N ₄ O) are as follows. The theoretical values are: C, 51.39%; H, 2.77%; N, 8.56%. Analytical values: C, 51.75%; H, 2.91%; N, 8.37%.

II. Polybenzimidazole

The polybenzimidazole of the present invention is a tetraamine diphenyl ether represented by the above formula (1), which is also called a tetraamine monomer, and a diacid (also referred to as a diacid monomer) represented by the formula (4). As a monomer, a polymerization reaction is carried out, and polybenzimidazole has the following formula (5): HOOC-R-COOH formula (4)

Wherein X in the formula (5) is a halogen, an alkyl group, a haloalkyl group or a group containing an aromatic ring. The range of n is 40~800.

In one embodiment, R in formula (4) is a group containing an aromatic ring. The total carbon number of the group containing an aromatic ring is, for example, 6 to 15. For example, R in equation (4) can be

For example, the tetraamine monomer can be 4,4',5,5'-tetraamino-2,2'-dibromodiphenyl ether, 4,4',5,5'-tetraamino-2 , 2'-diphenyldiphenyl ether, 4,4',5,5'-tetraamino-2,2'-bis[3,5-bis(trifluoromethyl)phenyl]diphenyl ether or Other tetraaminodiphenyl ether represented by the formula (1). The diacid may be 4,4'-oxybis (benzoic acid, OBA), 4,4'-diphenyl acid (Biphenyl-4,4-dicarboxylic acid), 4, 4'-Hexafluoroisopropylidene bis(benzoic acid), isophthalic acid, terephthalic acid, 4,4'- Mercaptodibenzoic acid (4,4-Sulfonyldibenzoic acid) or other diacid represented by formula (4).

In one embodiment, when the tetraamine monomer is 4,4',5,5'-tetraamino-2,2'-dibromodiphenyl ether, the diacid monomer is 4,4'-hydroxydiphenyl. In the case of formic acid, the obtained polybenzimidazole has the following formula (6):

In one embodiment, when the tetraamine monomer is 4,4',5,5'-tetraamino-2,2'-diphenyldiphenyl ether, the diacid monomer is 4,4'-hydroxyl In the case of benzoic acid, the polybenzimidazole obtained by the following formula (7) represents:

In one embodiment, when the tetraamine monomer is 4,4',5,5'-tetraamino-2,2'-bis[3,5-bis(trifluoromethyl)phenyl]diphenyl ether When the diacid monomer is 4,4'-hydroxydibenzoic acid, the obtained polybenzimidazole has the following formula (8):

Next, an example of a method for synthesizing polybenzimidazole and confirming and analyzing the properties of the obtained compound will be described. Please refer to FIG. 8. In the following examples, 4,4',5,5'-tetraamino-2,2'-dibromodiphenyl ether (7) , 4, 4', 5, 5, respectively. '-Tetraamino-2,2'-diphenyldiphenyl ether (10) and 4,4',5,5'-tetraamino-2,2'-bis[3,5-bis(trifluoro Polybenzimidazoles (P1) , (P2) and (P3) were prepared as methylene phenyl]diphenyl ether (13) and 4,4'-hydroxydibenzoic acid as monomers, and TADE and TAB were used as As the comparative examples, polybenzimidazoles (P4) and (P5) were prepared as monomers.

Preparation of polybenzimidazole (P1)

First, the apparatus was equipped with a 25 ml three-necked round bottom flask with nitrogen in/out and mechanical stirrer, followed by 4,4',5,5'-tetraamino-2,2'-dibromo as a monomer. Phenyl ether (7) (0.3434 g, 0.88 mmol) and 4,4'-hydroxydibenzoic acid (0.2285 g, 0.88 mmol) were added thereto and maintained under a nitrogen atmosphere for 30 minutes. Next, 5.7 ml of Eaton's reagent was added and stirred at 80 to 100 ° C at 100 rpm until the monomer was completely dissolved. After the monomer is completely dissolved, the temperature is raised to 120 ° C for 1 hour, and then the temperature is raised to 145 ° C for 1.5 hours, and then the viscosity of the reaction solution is significantly increased. Next, the reaction solution was poured into water to form a filamentous precipitate. Next, the pH of the reaction solution was adjusted to 10 with sodium carbonate, and stirred at 80 ° C for 2 hours. Next, the precipitate was collected and washed with water until neutral, and then continuously extracted with ethanol for one day. Finally, it was dried under vacuum at 150 ° C to obtain 0.4827 g of a polymer, i.e., polybenzimidazole (P1) , in a yield of 95%.

Preparation of polybenzimidazole (P2)

Polybenzimidazole (P2) was prepared in the same procedure as in the preparation of polybenzimidazole (P1) except that 4,4',5,5'-tetraamino-2,2'-diphenyl was used. Diphenyl ether (10) as a tetraamine monomer.

Preparation of polybenzimidazole (P3)

Polybenzimidazole (P3) was prepared in the same procedure as in the preparation of polybenzimidazole (P1), except that 4,4',5,5'-tetraamino-2,2'-di was used [ 3,5-bis(trifluoromethyl)phenyl]diphenyl ether (13) was used as the tetraamine monomer.

Comparative Example Preparation of Polybenzimidazole (P4)

Polybenzimidazole (P3) was prepared in the same procedure as in the preparation of polybenzimidazole (P1) except that TADE was used as a monomer.

Comparative Example Preparation of Polybenzimidazole (P5)

Polybenzimidazole (P3) was prepared in the same procedure as in the preparation of polybenzimidazole (P1) except that TAB was used as the tetraamine monomer.

In addition, the intrinsic viscosity (η _inh ) and solubility of polybenzimidazoles (P1) , (P2), and (P3) were tested. The results are shown in Table 1 below, in which polybenzimidazole (P4) , (P5) As a comparative example.

The intrinsic viscosity (η _inh ) and molecular weight of polybenzimidazoles (P1) , (P2) and (P3) were measured, and the results are shown in Table 2 below.

It can be seen from Table 1 and Table 2 that polybenzimidazoles (P1) , (P2) and (P3) have suitable viscosity and good solubility, indicating that the novel polybenzimidazole is suitable for coating by solution casting. Scratch the film.

The thermal properties of polybenzimidazoles (P1) , (P2), and (P3) were measured, and the results are shown in Table 3 below.

As can be seen from Table 3, the 10% thermal cracking temperature (T _d10% ) of polybenzimidazole (P1) , (P2) and (P3) is 414, 430 and 521 ° C, respectively, and the glass transition temperature (T _g ) is 208, 417 and greater than 450 ° C, showing that the new polybenzimidazole has good thermal stability.

III. Proton exchange membrane

Next, a proton exchange membrane was prepared with polybenzimidazole (P1) , (P2), and (P3) , respectively, and the properties of the proton exchange membrane were tested.

Preparation of proton exchange membrane

First, polybenzimidazole (P1) , (P2) or (P3) is dissolved using N-methylpyrrolidone (NMP) as a solvent to prepare polybenzimidazole at a concentration of 3 to 5% (w/v). Solution. The polybenzimidazole solution was centrifuged at 6000 rpm for 1 hour using a centrifuge, and the supernatant clarified polybenzimidazole solution was collected. Next, the polybenzimidazole solution was cast on a glass plate and then baked at 60 ° C for 6 hours. Then, the film was immersed in water at 80 ° C for 2 hours, and finally the film was pressure-pressed in a vacuum oven at 200 ° C for 6 hours to obtain a flat polybenzimidazole film, which was then cut into an appropriate size for subsequent film property test.

Oxidative stability test of polybenzimidazole film

First, a 3% aqueous solution of H ₂ O ₂ containing 4 ppm of Fe ^{2+ was} formulated. The weight ( W _i ) of the vacuum-dried polybenzimidazole film (2 cm × 2 cm) was weighed, and then immersed in the above aqueous solution, and tested at 68 °C. The film was taken out every 24 hours, the film was washed several times with deionized water, vacuum dried, then the weight of the film ( W _f ), and calculated by W _loss = ( W _i - W _f ) / W _i × 100% The percentage of weight loss ( W _loss ). Repeat this process for more than 200 hours. The oxidation stability results are shown in Fig. 9, in which P4 and mPBI were used as comparative examples.

It can be seen from Fig. 9 that in the oxidation stability test, the weight loss percentage ( W _loss ) of the P1 to P3 film after the 216 hour test is 16.9, 10.2, and 4.4%, indicating good oxidation of the novel polybenzimidazole film. stability.

Phosphoric doping process of polybenzimidazole film

After drying the polybenzimidazole film (2 cm x 2 cm) at 100 ° C, the dry film weight ( W _dry ) was weighed. The vacuum-dried polybenzimidazole film was immersed in a phosphoric acid solution having a concentration of 60%, 75%, 80%, and 85%, respectively, for three days to carry out phosphoric acid doping of the film. Among them, the Phosphoric acid content (PA content) is defined as the percentage of the doped phosphoric acid weight to the dry film weight ( W _dry ), that is, the PA content = ( W _wet - W _dry ) / W _dry × 100%.

Mechanical strength test of polybenzimidazole film

The polybenzimidazole film was cut into a size of 1 cm × 5 cm, and the aforementioned phosphoric acid doping process was carried out. After measurement, the thickness of the film is 30 to 50 μm. Using the Universal Testing Machine model Testometric M500-25AT, the mechanical strength test was carried out under normal temperature and pressure using a load cell of 10 kgf, and the measurement rate was 5 mm/min (5 mm/min). ), the results are shown in Table 4 below.

Proton conductivity test of polybenzimidazole film

The polybenzimidazole film was cut into a size of 1 cm × 2 cm, and the aforementioned phosphoric acid doping process was carried out to prepare a proton exchange membrane. After measurement, the thickness of the proton exchange membrane is 30 to 50 μm. The proton conduction impedance of this proton exchange membrane was measured using a two-point electrochemical impedance spectroscopy (EIS). First, the proton exchange membrane is fixed to the electrode. Next, the temperature was raised to 120 ° C for half an hour to remove moisture in the film. Subsequently, the proton conduction resistance test was started after the temperature was lowered to 60 °C. High voltage and low voltage are applied to both ends of the electrode, and are conducted with a fixed alternating current. At this time, the proton conduction resistance (R, Ω) was measured by a change in current frequency (100000 Hz to 1 Hz). Next, the proton conduction resistance of the film was measured at 80 ° C, 100 ° C, 120 ° C, 140 ° C, and 160 ° C at a temperature difference of 20 ° C, respectively. The proton conductivity is calculated by the equation of σ(Scm ^-1 )=L(cm)/R(Ω)A(cm ² ), where σ is the proton conductivity, L is the distance between the electrodes, and A is the proton. The cross-sectional area of the exchange membrane, and R is the impedance value measured by the electrochemical impedance meter. In this test, the distance L between the electrodes was 1.1 cm. The width and thickness of the film are measured before measuring the impedance. The results are shown in Table 5 below, in which poly-2,2'-(m-phenyl)-5,5'-bibenzimidazole (poly-2,2'-(m-phenylene)-5,5'- Bibenzimidazole (mPBI)) was used as a comparative example.

It can be seen from Table 5 that the novel polybenzimidazole film is doped with phosphoric acid at different concentrations in a phosphoric acid solution at room temperature to obtain a similar phosphoric acid doping amount (PA content, %), which is between 160 and 200%. The novel polybenzimidazole films having a phosphoric acid doping amount of about 200% at 160 ° C have proton conductivity of 3.99 × 10 ^-2 , 5.18 × 10 ^-2 and 5.34 × 10 ^-2 S cm ^-1 , respectively.

IV. Fuel cell

In an embodiment of the present invention, as shown in FIG. 10, a Membrane electrode assembly 100 of a fuel cell includes, for example, a first fuel gas diffusion layer 110, an anode catalyst layer 120, a proton exchange membrane 130, and a cathode. The catalyst layer 140 and the second fuel gas diffusion layer 150. The proton exchange membrane 130 is disposed between the anode catalyst layer 120 and the cathode catalyst layer 140, and the proton exchange membrane 130 is formed of the aforementioned polybenzimidazole doped with phosphoric acid. The anode catalyst layer 120 is located between the first fuel diffusion layer 110 and the proton exchange membrane 130. The cathode catalyst layer 140 is located between the second fuel diffusion layer 150 and the proton exchange membrane 130. In the present embodiment, the anode catalyst layer 120 and the cathode catalyst layer 140 are, for example, poly-2,2'-(m-phenyl)-5,5'-bibenzimidazole (mPBI) and 40% Pt/. Formed by C. Of course, although in the present embodiment, the membrane electrode assembly 100 of the fuel cell illustrated in FIG. 10 is taken as an example, the present invention is not limited thereto, that is, in other In an embodiment, the fuel cell may also have other layers.

Next, a polybenzimidazole film having a different doping amount of phosphoric acid was used as a proton exchange membrane in a single cell, and the characteristics of the single cell were tested.

Single battery test

The catalyst and mPBI mixture solution (Catalyst ink solution) was prepared by using N,N-dimethylacetamide (DMAc) as a solvent and stirred for 2 hours, wherein the catalyst was Pt/C (40% Pt attached to carbon black). (carbon black) (40% Pt, 60% C), Johnson Matthey Company, ratio of Pt/C, mPBI to DMAc is 20:1:400 (weight: weight: volume (μl) ). The uniformly stirred mixed solution was uniformly coated on a carbon cloth as a cathode and an anode with a micropipette (20 μl), and then the carbon was placed in an oven at 70 ° C for drying. The Pt contents of the cathode and the anode were calculated to be about 0.8 mg/cm ² and 0.6 mg/cm ^{2 , respectively} . Then, the carbon cloth coated with the catalyst layer was immersed in 20 wt% of H ₃ PO ₄ for two days to complete the fabrication of the electrode. Then, the unit cells are stacked in the order of the flow field plate/gasket/anode/proton exchange membrane/cathode/gasket/flow field plate, wherein the single electrode is a stacked structure of the unheated membrane electrode assembly . Then, the cells were placed between the end plates, and the battery was fixed by a pneumatic single cell fixture (ASCT-5, Asia Pacific Fuel Cell Company). Next, a single cell test was conducted using a test machine FCED-P 200 manufactured by Asia Pacific Fuel Cell Co., Ltd., and hydrogen gas was introduced into the anode and oxygen was introduced into the cathode. The gas flow rates of the anode and the cathode were 0.2 and 0.5 L/min, respectively, and the inside of the control cell was maintained at a pressure of 2 atm (1 atm back pressure). The results are shown in Fig. 11, in which P4 and mPBI were used as comparative examples.

It can be seen from Fig. 11 that the P1 film with a phosphoric acid doping amount of 241% can reach a power density of 477 mW/cm ² at 160 ° C; the phosphoric acid doping amount is 210% P 2 film can reach a power density of 497 mW/cm ² at 140 ° C; A P3 film having a phosphoric acid doping amount of 199% can reach a power density of 635 mW/cm ² at 160 °C.

The invention uses 4,4'-diaminodiphenyl ether as a starting material to synthesize a novel tetraaminodiphenyl ether containing a 4,4'-diphenyl ether structure, and the novel tetraaminodiphenyl ether can be 4,4',5,5'-tetraamino-2,2'-dibromodiphenyl ether, 4,4',5,5'-tetraamino-2,2'-diphenyldiphenyl ether And 4,4',5,5'-tetraamino-2,2'-bis[3,5-bis(trifluoromethyl)phenyl]diphenyl ether. That is to say, the soft structure of 4,4'-diphenyl ether is utilized, and at the same time, a large side group is introduced to increase the solubility of the novel polybenzimidazole during polymerization and after polymerization. Therefore, the novel polybenzimidazole has a good solubility and can be easily coated into a flexible film by a method such as solution casting. In this way, the processability of the polybenzimidazole is improved, and the applicability is improved. In addition, the proton exchange membrane prepared by the novel polybenzimidazole has high mechanical strength, thermal stability, oxidative stability and proton conductivity, and thus the fuel cell using the same has good battery efficiency.

In summary, the technical features of the present invention include a novel tetraaminodiphenyl ether, a novel polybenzimidazole prepared by using the tetraaminodiphenyl ether, and a proton exchange membrane obtained by using the polybenzimidazole. And a fuel cell including the proton exchange membrane. The novel polybenzimidazole has good solubility, thereby improving the processability of polybenzimidazole and improving its applicability. In addition, the proton exchange membrane produced by the novel polybenzimidazole has high mechanical strength, thermal stability, oxidative stability and proton conductivity, and thus the fuel cell using the same has good battery efficiency.

Although the present invention has been disclosed above by way of example, it is not intended to limit the present invention. The scope of the present invention is defined by the scope of the appended claims, which are defined by the scope of the appended claims, without departing from the spirit and scope of the invention. quasi.

Claims (10)

A tetraaminodiphenyl ether, the following formula (1) represents: Wherein X in the formula (1) is a halogen, an alkyl group, a haloalkyl group or a group containing an aromatic ring. The tetraaminodiphenyl ether according to claim 1, wherein X is fluorine, chlorine, bromine, iodine, methyl, trifluoromethyl, , or The tetraaminodiphenyl ether according to claim 1, wherein the following formula (2) represents: The tetraaminodiphenyl ether according to claim 1, wherein the following formula (3) represents: Wherein Y in the formula (3) is hydrogen or a haloalkyl group. A polybenzimidazole obtained by a polymerization reaction of a tetraaminodiphenyl ether as described in claim 1 and a diacid represented by the formula (4) as a monomer, the polyphenylene And imidazole is represented by the following formula (5): HOOC-R-COOH formula (4) Wherein X in the formula (5) is a halogen, an alkyl group, a haloalkyl group or a group containing an aromatic ring. Polybenzimidazole as described in claim 5, wherein R in the formula (4) It is a group containing an aromatic ring. The polybenzimidazole according to claim 5, wherein R in the formula (4) is The polybenzimidazole according to claim 5, wherein the following formula (6), formula (7) or formula (8) represents: A proton exchange membrane formed of polybenzimidazole as described in claim 5, which is doped with phosphoric acid. A fuel cell comprising: an anode catalyst layer; a cathode catalyst layer; and a proton exchange membrane disposed between the anode catalyst layer and the cathode catalyst layer, as described in claim 9 .