KR20220149299A - Poly(benzopheneone) based polymer for proton exchange membrane of fuel cell, polymer proton exchange membrane for fuel cell, and fuel cell comprising the same - Google Patents

Abstract

The present invention relates to a polymer for a fuel cell proton exchange membrane represented by a structural formula 1 below. As a result, compared to a conventional polymeric proton exchange membrane having a sulfuric acid group, the polymer for the fuel cell proton exchange membrane has high ionic conductivity, mechanical strength and chemical strength.

Description

Poly(benzophenone)-based polymer for fuel cell proton exchange membrane, polymer proton exchange membrane for fuel cell and fuel cell containing the same COMPRISING THE SAME}

The present invention relates to a polymer for a fuel cell proton exchange membrane, a polymer proton exchange membrane for a fuel cell comprising the same, and a fuel cell, and more particularly, to a poly(benzophenone)-based polymer for a fuel cell proton exchange membrane that can replace Nafion, the It relates to a polymer proton exchange membrane for a fuel cell, including a fuel cell.

Eco-friendly proton exchange membrane fuel cells (PEMFCs) are an effective replacement for fossil fuels. In PEMFC, the polymer electrolyte membrane plays a role in converting H ₂ and the oxidizing agent into electrical energy. Therefore, polymer electrolyte membrane materials are a key research area for fuel cells. Nafions®, a polyfluorosulfonic acid (PFSA)-based membrane, is considered a standard use material for proton exchange membranes (PEMs), but its application is limited by high cost, harsh manufacturing processes and difficulties in structural modification. Aromatic hydrocarbon-based polymers with different polymer backbones are already being studied as alternatives to PFSA-based membranes.

Although pre-sulfonation using sulfonated monomers has been found to be more convenient than post-sulfonation of membranes, it is often very difficult to obtain high molecular weight polymers from sulfonated monomers. . In addition, although most of these sulfonated polymers exhibit oxidative and hydrolytic stability, they are vulnerable to nucleophile attack because the polymer backbone is based on an ether bond and an acid functional group is attached to the main chain. .

In general, the low acidity of the sulfonic acid group is also a cause of poor conductivity of the fuel cell. Therefore, researchers investigated alternative acid functional groups with non-fluorinated or partially fluorinated membranes in addition to perfluorosulfonic acid (PFSA). Recently, sulfonimide membranes have become a major concern for their super gas-phase acidity and excellent thermal stability. A higher charge delocalization capacity appears to be responsible for the higher acidity. As a result, polymer membranes using sulfonimide groups are being studied and considered as potential candidates for fuel cell applications. Most sulfonimide membranes also suffer from poor chemical stability due to the ether linkage of the main polymer backbone.

Korean Patent Publication No. 10-2195258

An object of the present invention is a poly(benzophenone)-based polymer for a fuel cell proton exchange membrane having high proton conductivity, thermal stability, and chemical stability while being able to replace the conventional Nafion proton exchange membrane, which is not environmentally friendly and has high manufacturing cost, and for fuel cells including the same To provide a polymer proton exchange membrane and a fuel cell.

According to one aspect of the present invention,

A polymer for a fuel cell proton exchange membrane represented by the following Structural Formula 1 is provided.

[Structural Formula 1]

In Structural Formula 1,

m and n are the number of repeating units,

R ¹ is a fluorine group, a chloro group, a C1 to C20 fluoroalkyl group, or a C1 to C20 chloroalkyl group,

R ² is a hydrogen atom or a C1 to 20 alkyl group.

Preferably,

The compound represented by Structural Formula 1 may be represented by Structural Formula 2 below.

[Structural Formula 2]

In Structural Formula 2,

m and n are the number of repeating units,

R ¹ is a fluorine group, a chloro group, a C1 to C20 fluoroalkyl group, or a C1 to C20 chloroalkyl group,

R ² is a hydrogen atom or a C1 to 20 alkyl group.

More preferably,

In Structural Formula 2,

m and n are the number of repeating units,

R ¹ is each independently a fluorine group, a chloro group, a C1 to C10 fluoroalkyl group, or a C1 to C20 chloroalkyl group,

R ² may be each independently a hydrogen atom or a C1 to 10 alkyl group.

Even more preferably,

In Structural Formula 2,

m and n are the number of repeating units,

R ¹ is a fluorine group,

R ² may be a hydrogen atom.

The compound represented by Structural Formula 1 may have a weight average molecular weight (Mw) of 50,000 to 200,000.

The number of repeating units, m:n, may be in a ratio of 50:50 to 70:30.

According to another aspect of the present invention,

(a) preparing poly (benzophenone) (PBP) by C-C coupling reaction of 2,5-dichlorobenzophenone (DCBP) monomer under a nickel-based catalyst;

(b) preparing sulfonated poly(benzophenone) (S-PBP) by mixing the poly(benzophenone) (PBP) with an organic solvent and reacting it with chlorosulfuric acid; and

(c) reacting the sulfonated poly(benzophenone) (S-PBP) with a compound represented by the following structural formula 3 to prepare a polymer for a fuel cell proton exchange membrane represented by the following structural formula 1; a fuel cell comprising a A method for preparing a polymer for a proton exchange membrane is provided.

[Structural Formula 1]

In Structural Formula 1,

m and n are the number of repeating units,

R ¹ is a fluorine group, a chloro group, a C1 to C20 fluoroalkyl group, or a C1 to C20 chloroalkyl group,

R ² is a hydrogen atom or a C1 to 20 alkyl group.

[Structural Formula 3]

In Structural Formula 3,

R ³ is a fluorine group, a chloro group, a C1 to C20 fluoroalkyl group, or a C1 to C20 chloroalkyl group,

R ⁴ is a hydrogen atom or a C1 to 20 alkyl group.

In step (a),

The nickel-based catalyst may include any one transition metal selected from Zn, Pt, Pd, Ru, Rh, Ni, Fe, Cu, Co, Cr, Au, Re, and Zr; and organic ligands.

The organic ligand is triphenylphosphine, pentamethylcyclopentadiene, cyclooctadiene, benzene, ethylenediamine, and acetylacetonate among It may be any one selected or a derivative thereof.

In step (a),

The C-C coupling reaction is

(a-1) 2,5-dichlorobenzophenone (DCBP) monomer under the nickel catalyst dimethylacetamide (DMAc), N-methylpyrrolidone (NMP), dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) ) to prepare a jelly-like mixture by stirring the mixed solution dissolved in any one solvent selected from;

(a-2) diluting the jelly-like mixture and cooling it to room temperature; and

(a-3) putting the cooled mixture in an acidic aqueous solution to obtain a solid; may include.

The stirring of the mixed solution in step (a-1) may be performed at 80 to 120 °C.

The reaction of step (b) may be carried out while stirring at 70 to 90 ℃.

in Structural Formula 3

R ³ is a fluorine group, or a C1 to C10 fluoroalkyl group,

R ⁴ may be a hydrogen atom or a C1 to 10 alkyl group.

The step (c) is,

(c-1) reacting the sulfonated poly(benzophenone) (S-PBP) with thionyl chloride (SOCl ₂ ) to prepare a reaction mixture;

(c-2) refluxing the reaction mixture and evaporating the reflux product to obtain a residue; and

(c-2) reacting the residue with the compound represented by Structural Formula 3 to prepare a polymer for a fuel cell proton exchange membrane represented by Structural Formula 1; may include.

The reaction of step (c-3) may be carried out at 0 to 5 ℃.

According to another aspect of the present invention,

There is provided a polymer proton exchange membrane for a fuel cell comprising the polymer for the fuel cell proton exchange membrane.

According to another aspect of the present invention,

There is provided a method for producing a polymer proton exchange membrane for a fuel cell, including the method for producing the polymer for the fuel cell proton exchange membrane.

According to another aspect of the present invention,

There is provided a fuel cell including the polymer proton exchange membrane for the fuel cell.

According to another aspect of the present invention,

An electric device including the fuel cell is provided.

The electrical device may be any one selected from a communication device, a transportation device, an energy storage device, and an acoustic device.

The polymer for a fuel cell proton exchange membrane of the present invention can improve ionic conductivity by introducing a sulfonylimide group having a lower acid dissociation constant (pKa) than a sulfuric acid group, and has high mechanical strength by introducing a benzophenone group, and a polymer proton using a conventional sulfone group Unlike the exchange membrane, since it does not contain an ether group in the polymer main chain, it can inhibit the decomposition of the polymer from oxygen radicals or hydroxide ions generated when the fuel cell is driven, and can replace the conventional Nafion electrolyte membrane. In addition, if such a polymer for a fuel cell proton exchange membrane is applied to the proton exchange membrane for a fuel cell, as a result, the electrochemical performance of the fuel cell can be improved.

1 is an FT-IR analysis result according to Experimental Example 1.
2 is a 1H-NMR analysis result of the polymer according to Experimental Example 1.
3 is a result of 19F-NMR analysis according to Experimental Example 1.
4 is an ion exchange capacity (IEC) and water absorption rate (WU) analysis results of the proton exchange membrane according to Experimental Example 2.
5 is a result of proton conductivity analysis according to Experimental Example 3.
6 is a thermal-oxidation stability analysis result according to Experimental Example 4.
7 is a chemical stability analysis result according to Experimental Example 5.
8 is a morphology analysis result of a membrane by an atomic force microscope according to Experimental Example 6.
9 is a cell performance analysis result according to Experimental Example 7.

Hereinafter, various aspects and various embodiments of the present invention will be described in more detail. Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art can easily carry out the present invention. However, the following description is not intended to limit the present invention to specific embodiments, and when it is determined that a detailed description of a related known technology may obscure the gist of the present invention in describing the present invention, the detailed description thereof will be omitted. . The terminology used herein is used only to describe specific embodiments, and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as "comprise" or "have" are intended to designate that a feature, number, step, operation, element, or combination thereof described in the specification exists, but is one or more other features or It should be understood that the possibility of the presence or addition of numbers, steps, acts, elements, or combinations thereof is not precluded in advance.

Hereinafter, the poly(benzophenone)-based polymer for a fuel cell proton exchange membrane of the present invention will be described.

The poly(benzophenone)-based polymer for a fuel cell proton exchange membrane of the present invention is represented by the following structural formula (1).

[Structural Formula 1]

In Structural Formula 1,

m and n are the number of repeating units,

R ¹ is a fluorine group, a chloro group, a C1 to C20 fluoroalkyl group, or a C1 to C20 chloroalkyl group,

R ² is a hydrogen atom or a C1 to 20 alkyl group.

Preferably,

The compound represented by Structural Formula 1 may be represented by Structural Formula 2 below.

[Structural Formula 2]

In Structural Formula 2,

m and n are the number of repeating units,

R ¹ is a fluorine group, a chloro group, a C1 to C20 fluoroalkyl group, or a C1 to C20 chloroalkyl group,

R ² is a hydrogen atom or a C1 to 20 alkyl group.

More preferably,

In Structural Formula 2,

m and n are the number of repeating units,

R ¹ is each independently a fluorine group, a chloro group, a C1 to C10 fluoroalkyl group, or a C1 to C20 chloroalkyl group,

R ² may be each independently a hydrogen atom or a C1 to 10 alkyl group.

Even more preferably,

In Structural Formula 2,

m and n are the number of repeating units,

R ¹ is a fluorine group,

R ² may be a hydrogen atom.

Preferably, the compound represented by Structural Formula 2 may have a weight average molecular weight (Mw) of 50,000 to 200,000, preferably 80,000 to 160,000, and more preferably 100,000 to 130,000.

The number of repeating units, m:n, is preferably 30:70 to 90:10, more preferably 40:60 to 80:20, and even more preferably 50:50 to 70:30. When the relative ratio of m is lower than the ratio, the ratio of the sulfonimide group to the entire polymer for proton exchange membrane is low, so the degree of channel formation for proton conduction may be insufficient. When the relative ratio of m is higher than the ratio, thermal Stability or chemical stability may be reduced.

Hereinafter, a method for producing a poly(benzophenone)-based polymer for a fuel cell proton exchange membrane of the present invention will be described.

First, 2,5-dichlorobenzophenone (DCBP) monomer is subjected to a C-C coupling reaction under a nickel-based catalyst to prepare poly(benzophenone) (PBP) (step a).

The nickel-based catalyst may include any one transition metal selected from Zn, Pt, Pd, Ru, Rh, Ni, Fe, Cu, Co, Cr, Au, Re and Zr; and an organic ligand. The transition metal is more preferably used as a Ni-Zn composite transition metal catalyst by adding Zn.

The organic ligand is triphenylphosphine, pentamethylcyclopentadiene, cyclooctadiene, benzene, ethylenediamine, and acetylacetonate among It may be any one selected or a derivative thereof, and preferably triphenylphosphine may be used.

The C-C coupling reaction is specifically preferably performed sequentially according to the following method.

First, 2,5-dichlorobenzophenone (DCBP) monomer was prepared in dimethylacetamide (DMAc), N-methylpyrrolidone (NMP), dimethylformamide (DMF) and dimethylsulfoxide (DMSO) under the nickel-based catalyst. The mixed solution dissolved in any one selected solvent is stirred to prepare a jelly-like mixture (step a-1).

The stirring of the mixed solution is preferably carried out at 80 to 120 °C, more preferably at 90 to 110 °C.

Next, the jelly-like mixture is diluted and cooled to room temperature (step a-2).

The cooled mixture is put into an acidic aqueous solution to obtain a solid (step a-3).

The acid solution is preferably used as an aqueous solution of a strong acid such as hydrochloric acid, nitric acid, or sulfuric acid.

Next, the poly(benzophenone) (PBP) is mixed with an organic solvent and reacted with chlorosulfuric acid to prepare sulfonated poly(benzophenone) (S-PBP) (step b).

The reaction in this step is preferably carried out while stirring at 70 to 90 ℃, more preferably it may be carried out at 75 to 85 ℃.

The organic solvent may be dichloromethane, dimethylformamide, tetrahydrofuran, ethyl acetate, acetonitrile, dioxane, ethanol, and the like.

Thereafter, the sulfonated poly(benzophenone) (S-PBP) is reacted with a compound represented by the following structural formula 3 to prepare a polymer for a fuel cell proton exchange membrane represented by the following structural formula 1 (step c).

[Structural Formula 1]

In Structural Formula 1,

m and n are the number of repeating units,

R ¹ is a fluorine group, a chloro group, a C1 to C20 fluoroalkyl group, or a C1 to C20 chloroalkyl group,

R ² is a hydrogen atom or a C1 to 20 alkyl group.

[Structural Formula 3]

In Structural Formula 3,

R ³ is a fluorine group, a chloro group, a C1 to C20 fluoroalkyl group, or a C1 to C20 chloroalkyl group,

R ⁴ is a hydrogen atom or a C1 to 20 alkyl group.

Preferably, in Structural Formula 3,

R ³ is a fluorine group, or a C1 to C10 fluoroalkyl group,

R ⁴ may be a hydrogen atom or a C1 to 10 alkyl group.

More preferably, the compound represented by Structural Formula 3 may be a fluorosulfonamine (FSO ₂ NH ₂ ).

This step is specifically preferably performed in the following order.

First, the sulfonated poly(benzophenone) (S-PBP) is reacted with thionyl chloride (SOCl ₂ ) to prepare a reaction mixture (step c-1).

Then, the reaction mixture is refluxed, and the reflux product is evaporated to obtain a paste-like residue (step c-2).

Next, the residue is reacted with the compound represented by Structural Formula 3 to prepare a polymer for a fuel cell proton exchange membrane represented by Structural Formula 1 (step c-3).

The reaction of step (c-3) is preferably carried out at 0 to 5°C.

When the reaction is completed, the sulfonimide poly(benzophenone) compound represented by Structural Formula 1 may be finally obtained by putting it in an aqueous alcohol solution.

In addition, the present invention provides a polymer proton exchange membrane for a fuel cell comprising the poly(benzophenone)-based polymer for the fuel cell proton exchange membrane.

In addition, the present invention provides a method for manufacturing a polymer proton exchange membrane for a fuel cell, including a method for manufacturing a poly(benzophenone)-based polymer for a fuel cell proton exchange membrane.

In addition, the present invention provides a fuel cell including the polymer proton exchange membrane for the fuel cell.

In addition, the present invention provides an electric device including the fuel cell.

The electrical device may be a communication device, a transportation device, an energy storage device, an acoustic device, or the like.

Hereinafter, examples according to the present invention will be described in detail.

[Example]

Scheme 1 below schematically shows the synthesis process of poly(benzophenone) according to Preparation Examples 1 to 3 of the present invention.

SI-PBP polymer was synthesized by CC coupling polymerization of DCBP monomer using Ni(0) catalyst. The molar ratio of catalyst plays an important role in obtaining high molecular weight polymers. Therefore, a molar ratio of catalyst NiBr ₂ :PPh3 : Zn (1:10:40) was applied to PBP polymer synthesis. In addition, chlorosulfonation of the PBP polymer (S-PBP) was obtained by controlling the amount and time of exposure to chlorosulfonic acid. Then, sulfonimidization was performed using thionyl chloride (SOCl ₂ ) and fluorosulfonamine (FSO ₂ NH ₂ ), respectively.

[Scheme 1]

Hereinafter, a specific manufacturing method has been described.

Preparation Example 1: Poly (benzophenone) (PBP) synthesis

2,5-dichlorobenzophenone (DCBP) monomer was synthesized from 2,5-dichlorotoluene and then synthesized by Friedel-Craft acylation with benzene. NiBr ₂ (0.366 g, 1.19 mmol), Zn powder (4.54 g, 71.68 mmol), triphenylphosphine (2.51 g, 9.56 mmol) were charged in a 3-neck catalyst flask in a glove box, and 2,5-dichlorobenzophenone ( DCBP) monomer (3.0 g, 11.95 mmol) was charged to another flask. DMAc (3-5 mL) was added to the catalyst flask by syringe and stirred with a mechanical stirrer under nitrogen flow. The solution was stirred at 80° C. until it turned red. The DCBP monomer was then dissolved in DMAc solvent and added to the catalyst flask via syringe. The mixture was stirred at 100° C. for 12 hours to give a viscous dark mixture. The viscous mixture was diluted with 8-10 mL of DMAc and cooled to room temperature. Then, the solution was added to distilled water containing 30% HCl while stirring, and when a solid was formed, the solution was filtered and washed with distilled water and methanol, respectively. Finally, poly(benzophenone) (PBP), a white solid polymer, was dried in a vacuum oven at 60° C. for 12 hours.

Preparation Example 2: Synthesis of sulfonated poly(benzophenone) (SPBP)

First, the PBP polymer (2.0 g, 7.96 mmol) prepared according to Preparation Example 1 was dissolved in chloroform (10 ml) at 25°C. Concentrated chlorosulfuric acid (3.18 mL, 47.8 mmol) was slowly added at 0°C and stirred at 80°C for 6 hours. The black solution was poured into ice water and stirred vigorously to give a yellow solid. Finally, the yellow solid polymer was rinsed with distilled water and dried at 60° C. for 24 hours.

Preparation Example 3: Synthesis of sulfonimide poly (benzophenone) (SI-PBP)

A 100 mL flask was filled with the SPBP polymer prepared according to Preparation Example 2 (2.0 g, 5.66 mmol), dichloromethane (15 mL) and thionyl chloride (SOCl ₂ ) (20 mL). The mixture was refluxed with 2 mL DMF at 75° C. for 24 h, and then all solvents were evaporated to give a viscous solution. The resulting viscous solution was diluted with dichloromethane (15 mL) and fluorosulfonamine (2.24 g, 22.65 mmol) was added slowly at 0°C. The mixture was stirred at 25° C. for 12 hours, and the resulting orange solution was added to methanol to obtain a sulfonimide poly(benzophenone) polymer (SI-PBP).

Example 1: Preparation of a proton exchange membrane (SI-PBP 1)

0.3 g of SI-PBP prepared according to Preparation Example 3 was dissolved in 5 mL of DMAc solvent to make a 6% (w/v) solution, and a silicone rim of 3 cm x 3 cm was installed on a glass plate, and the solution was put inside under an IR lamp overnight. SI-PBP1 proton exchange membrane with a thickness of 25 μm was prepared by exposure to

Example 2: Preparation of proton exchange membrane (SI-PBP 2)

SI-PBP 2 proton having a thickness of 25 μm under the same conditions as in Example 1 except that SI-PBP2 having a fluorosulfonimide group content of 5:6 as compared to SI-PBP of Preparation Example 3 was used. An exchange membrane was prepared.

Example 3: Preparation of proton exchange membrane (SI-PBP 3)

SI-PBP 3 protons having a thickness of 25 μm under the same conditions as in Example 1 except that SI-PBP3 having a fluorosulfonimide group content of 5:7 was used compared to SI-PBP of Preparation Example 3 An exchange membrane was prepared.

Device Example 1: Single cell Produce

A membrane electrode assembly (MEA) with an active area of 25 cm ² was prepared by a decal method based on a catalyst-coated membrane (CCM). As a gas diffusion layer (GDL) on the anode and cathode sides, 20 wt% wet-proof carbon paper with a thickness of 190 mm was used.

Carbon-supported Pt was used as a catalyst for both the anode and the cathode, and the loading of the catalyst layer was 0.29 mg Pt/cm ² . Then, the catalyst layer was transferred to the SI-PBP 1 proton exchange membrane of Example 1 by a decal method at 120° C. and 10 MPa for 5 minutes to make a CCM. GDLs were placed on the positive and negative sides of the CCM to form a membrane electrode assembly (MEA), and a single cell was assembled.

Device Example 2: Single cell Produce

A single cell was manufactured under the same conditions as in Device Example 1, except that the SI-PBP 2 proton exchange membrane of Example 2 was used instead of the SI-PBP 1 proton exchange membrane of Example 1

Device Example 3: Single cell Produce

A single cell was manufactured under the same conditions as in Device Example 1, except that the SI-PBP 3 proton exchange membrane of Example 2 was used instead of the SI-PBP 1 proton exchange membrane of Example 1

[Test Example]

Experimental Example 1: FT-IR analysis

1 is a FT-IR (Fourier Transform Infrared Spectrometer) analysis results for polymers prepared according to Preparation Examples 1 to 3; According to Figure 1, a wide stretching frequency in the range of 2800-3600 cm ^-1 corresponds to the -OH vibration frequency of the S-PBP polymer. The stretching frequencies at 1420 and 1190 cm ⁻¹ correspond to the S = O phase, whereas for the C = O bond they correspond to those at 1680 cm ⁻¹ .

2 is a 1H-NMR analysis result of the polymers of Preparation Examples 1 to 3. According to this, the peak around 6.50-7.78 ppm corresponds to the proton of the aromatic ring for the PBP and SPBP polymers. The -SO ₃ H peak of the SPBP polymer is observed in the upfield at 4.0 ppm due to its binding to water and solvent DMSO. However, the aromatic proton peak of the SI-PBP polymer shifted downfield at 6.50-8.60 ppm due to the delocalization performance of the sulfonimide anion. A characteristic large NH peak was observed at 4.90-5.70 ppm.

3 is a 19F-NMR analysis result of the polymers of Preparation Examples 1 to 3. According to this, as a characteristic 19F peak appears near -162 ppm, it can be confirmed that the sulfonylimide group is attached to the polymer backbone.

Experimental Example 2: Analysis of Ion Exchange Capacity (IEC), Water Absorption Rate (WU) and Dimensional Stability

4 is an ion exchange capacity (IEC) and water absorption rate (WU) analysis results of each of the proton exchange membranes prepared according to Examples 1 to 3; According to this, the water absorption rate gradually increased from 22.72 to 64.29%, and the ion exchange capacity also increased from 1.85 to 2.30 meq./g.

In Tables 1 and 2 below, the properties of the proton exchange membrane prepared according to Examples 1 to 3 and Nafion 211® were compared and summarized.

The charge delocalization ability of the sulfonimide acid groups is correlated with the higher water content of the SI-PBP membrane. The SI-PBP film had relatively lower rate of dimensional change and dimensional stability (through-plane (Δt) and in-plane (Δl) changes) than Nafion 211®. SI-PBP membranes exhibited higher Dt (7.5%, 12.5% and 34.0%) and Δl (4.81%, 8.0% and 16.17%) values, whereas Nafion 211® showed (Δt = 31.98 and Δl = 14.2%) values. . The Δl value of the SI-PBP membrane was significantly lower than the Δt value due to the C-C bonded aromatic hard polymer backbone.

Experimental Example 3: Proton Conductivity Analysis

Figure 5 shows the proton conductivity of the SI-PBP membrane according to the temperature change (30-90 ℃) (a) and the proton conductivity of the SI-PBP membrane according to the relative humidity change (30-90%). According to this, the SI-PBP-3 membrane of Example 3 exhibited a much higher proton conductivity (107.07 mS/cm) than Nafion 211® (104.5 mS/cm) at 90° C. and 90% relative humidity, and the SI of Example 2 -PBP 2 showed similar proton conductivity (94.80 mS/cm) to Nafion 211® (104.5 mS/cm) under the same conditions. The proton conductivity of the SI-PBP membranes of Examples 1 to 3 increased with increasing humidity. The higher acidity and position of the sulfonimide group in the pendant benzophenone ring can increase the proton conductivity of the SI-PBP membrane by forming highly distinct ion channels for proton conduction.

Experimental Example 4: Thermal-oxidation stability analysis

6 shows the thermal decomposition curves of the SI-PBP membranes of Examples 1 to 3 and the PBP membrane to which the sulfonimide group is not bound in air. According to this, the PBP polymer showed one-step thermal decomposition at about 380 °C, and the SI-PBP film showed three-step degradation. Thermal decomposition in the range of 200-330, 340-475 and 475-610 °C accounts for the conversion of sulfonimides to sulfonic acid groups, -SO ₃ H group removal and polymer backbone degradation, respectively. Remarkably, the most advantageous point of the SI-PBP polymer is that it conducts protons in two steps, the -SO ₂ NHSO ₂ - group and the -SO ₃ H group, before the main polymer backbone is disrupted. In addition, the SI-PBP polymer is stable up to 550 °C, and the CC-bonded aromatic backbone is mainly related to the very good thermal stability of the SI-PBP membrane.

Experimental Example 5: Chemical stability analysis

7 shows the results of measuring the weight loss with time at 80° C. for 9 hours to measure the chemical stability of the SI-PBP membranes prepared according to Examples 1 to 3 using Fenton reagent. According to this, all SI-PBP membranes of Examples 1 to 3 exhibited superior chemical stability compared to sulfonated poly(aryleneethersulfone) (SPAES 40). The C-C polymer backbone is less susceptible to free radical attack and may exhibit higher chemical stability of the SI-PBP membrane due to the presence of fluorine atoms in the sulfonimide group.

Experimental Example 6: Analysis of membrane morphology

8 shows the surface appearance of the trapping mode of SI-PBP by atomic force microscopy (AFM). According to this, the brown compartment represents the hydrophobic aromatic domain, while the dark black channel-like part represents the hydrophilic sulfonimide group along with the moisture of the SI-PBP membrane. In general, the polymer backbone and the content of the acid moiety greatly influence the morphology of the polymer membrane. Therefore, the SI-PBP 3 membrane of Example 3 contains a larger number of sulfonylimide groups compared to the others, and thus a significantly larger number of hydrophilic channels appears. In contrast, it can be seen that the SI-PBP 1 membrane of Example 1 has less ion channels because it has relatively few sulfonylimide groups.

Experimental Example 7: Cell Performance Analysis

9 is a polarization curve for single cell performance including SI-PBP films prepared according to Device Examples 1 to 3; According to this, the cell including the SI-PBP 3 film of Device Example 3 had a higher maximum power density (0.638 W/cm ² ) than the cell including Nafion 211® (0.62 W/cm ² ). The cell including SI-PBP 1 of Device Example 1 and the cell including SI-PBP 2 of Device Example 2 showed similar cell performance to the cell including Nafion 211® over the entire current density range.

In the above, although embodiments of the present invention have been described, those of ordinary skill in the art can add, change, delete or add components within the scope that does not depart from the spirit of the present invention described in the claims. The present invention may be variously modified and changed by such as, and it will be said that it is also included within the scope of the present invention.

Claims (20)

A polymer for a fuel cell proton exchange membrane represented by the following Structural Formula 1;
[Structural Formula 1]

In Structural Formula 1,
m and n are the number of repeating units,
R ¹ is a fluorine group, a chloro group, a C1 to C20 fluoroalkyl group, or a C1 to C20 chloroalkyl group,
R ² is a hydrogen atom or a C1 to 20 alkyl group. According to claim 1,
The compound represented by Structural Formula 1 is a polymer for a fuel cell proton exchange membrane, characterized in that it is represented by the following Structural Formula 2;
[Structural Formula 2]

In Structural Formula 2,
m and n are the number of repeating units,
R ¹ is a fluorine group, a chloro group, a C1 to C20 fluoroalkyl group, or a C1 to C20 chloroalkyl group,
R ² is a hydrogen atom or a C1 to 20 alkyl group. 3. The method of claim 2,
In Structural Formula 2,
m and n are the number of repeating units,
R ¹ is each independently a fluorine group, a chloro group, a C1 to C10 fluoroalkyl group, or a C1 to C20 chloroalkyl group,
R ² is each independently a hydrogen atom, or a C1 to 10 alkyl group for a fuel cell proton exchange membrane. 4. The method of claim 3,
In Structural Formula 2,
m and n are the number of repeating units,
R ¹ is a fluorine group,
R ² is a polymer for a fuel cell proton exchange membrane, characterized in that it is a hydrogen atom. According to claim 1,
The compound represented by Structural Formula 1 has a weight average molecular weight (Mw) of 50,000 to 200,000 for a fuel cell proton exchange membrane. According to claim 1,
The number of repeating units, m:n, is a polymer for a fuel cell proton exchange membrane, characterized in that the ratio of 50:50 to 70:30. (a) preparing poly(benzophenone) (PBP) by CC-coupling a 2,5-dichlorobenzophenone (DCBP) monomer under a nickel-based catalyst;
(b) preparing sulfonated poly(benzophenone) (S-PBP) by mixing the poly(benzophenone) (PBP) with an organic solvent and reacting it with chlorosulfuric acid; and
(c) reacting the sulfonated poly(benzophenone) (S-PBP) with a compound represented by the following structural formula 3 to prepare a polymer for a fuel cell proton exchange membrane represented by the following structural formula 1; a fuel cell comprising a; A method for producing a polymer for a proton exchange membrane.
[Structural Formula 1]

In Structural Formula 1,
m and n are the number of repeating units,
R ¹ is a fluorine group, a chloro group, a C1 to C20 fluoroalkyl group, or a C1 to C20 chloroalkyl group,
R ² is a hydrogen atom or a C1 to 20 alkyl group.
[Structural Formula 3]

In Structural Formula 3,
R ³ is a fluorine group, a chloro group, a C1 to C20 fluoroalkyl group, or a C1 to C20 chloroalkyl group,
R ⁴ is a hydrogen atom or a C1 to 20 alkyl group. 8. The method of claim 7,
In step (a),
The nickel-based catalyst may include any one transition metal selected from Zn, Pt, Pd, Ru, Rh, Ni, Fe, Cu, Co, Cr, Au, Re, and Zr; and an organic ligand. 9. The method of claim 8,
The organic ligand is triphenylphosphine, pentamethylcyclopentadiene, cyclooctadiene, benzene, ethylenediamine, and acetylacetonate among A method for producing a polymer for a fuel cell proton exchange membrane, characterized in that it is any one selected or a derivative thereof. 8. The method of claim 7,
In step (a),
The CC coupling reaction is
(a-1) 2,5-dichlorobenzophenone (DCBP) monomer under the nickel catalyst dimethylacetamide (DMAc), N-methylpyrrolidone (NMP), dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) ) to prepare a jelly-like mixture by stirring the mixed solution dissolved in any one solvent selected from;
(a-2) diluting the jelly-like mixture and cooling it to room temperature; and
(a-3) putting the cooled mixture in an acidic aqueous solution to obtain a solid; Method for producing a polymer for a fuel cell proton exchange membrane comprising a. 11. The method of claim 10,
A method of producing a polymer for a fuel cell proton exchange membrane, characterized in that the stirring of the mixed solution in step (a-1) is performed at 80 to 120 °C. 8. The method of claim 7,
The reaction of step (b) is a method for producing a polymer for a fuel cell proton exchange membrane, characterized in that it is carried out while stirring at 70 to 90 ℃. 8. The method of claim 7,
in Structural Formula 3
R ³ is a fluorine group, or a C1 to C10 fluoroalkyl group,
R ⁴ is a hydrogen atom, or a method for producing a polymer for a fuel cell proton exchange membrane, characterized in that it is a C1 to 10 alkyl group. 8. The method of claim 7,
The step (c) is,
(c-1) reacting the sulfonated poly(benzophenone) (S-PBP) with thionyl chloride (SOCl ₂ ) to prepare a reaction mixture;
(c-2) refluxing the reaction mixture and evaporating the reflux product to obtain a residue; and
(c-2) reacting the residue with the compound represented by Structural Formula 3 to prepare a polymer for a fuel cell proton exchange membrane represented by Structural Formula 1; manufacturing method. 15. The method of claim 14,
The reaction of step (c-3) is a method for producing a polymer for a fuel cell proton exchange membrane, characterized in that it is carried out at 0 to 5 ℃. A polymer proton exchange membrane for a fuel cell comprising the polymer for a fuel cell proton exchange membrane of any one of claims 1 to 6. A method for manufacturing a polymer proton exchange membrane for a fuel cell, comprising the method for preparing a polymer for a fuel cell proton exchange membrane according to any one of claims 7 to 15. A fuel cell comprising the polymer proton exchange membrane for a fuel cell of claim 16. An electrical device comprising the fuel cell of claim 18 . 20. The method of claim 19,
The electrical device is an electrical device, characterized in that any one selected from a communication device, a transportation device, an energy storage device, and an acoustic device.

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