KR101877499B1 - Anion-exchange membrane based on polyether ether ketone copolymer and manufacturing method thereof - Google Patents

Abstract

TECHNICAL FIELD The present invention relates to a polyether ether ketone-based copolymer, and more particularly, to a polyether ether ketone-based copolymer having an imidazolium group introduced into a polyether ether ketone-based copolymer and having improved ionic conductivity, chemical stability, Series, an anion exchange membrane for a fuel cell including the same, and a method of manufacturing the same.

Description

TECHNICAL FIELD [0001] The present invention relates to a polyether ether ketone copolymer, an anion exchange membrane for fuel cells containing the same, and an anion exchange membrane based on the polyether ether ketone copolymer and a manufacturing method thereof.

TECHNICAL FIELD The present invention relates to a polyether ether ketone-based copolymer, and more particularly, to a polyether ether ketone-based copolymer having an imidazolium group introduced into a polyether ether ketone-based copolymer and having improved ionic conductivity, chemical stability, Series, an anion exchange membrane for a fuel cell including the same, and a method of manufacturing the same.

The anion exchange membrane (AEM) fuel cell has the potential to utilize non-noble metal electrode catalysts, easy oxidation of fuel, fast reduction rate of oxygen, crossover of reduced fuel, enhanced carbon monoxide tolerance of catalyst, (PEMFC) has been attracting much attention recently because of its many advantages such as low cost, low cost, and management. Therefore, anion exchange membrane is being studied as an alternative to proton exchange membrane (PEM).

As a polymer that can be used as such anion exchange membrane, high hydroxide conductivity, mechanical strength, and chemical stability are considered to be essential.

Until recently, polymers having major polymer chains such as poly (vinyl alcohol), poly (phenylene), and poly (arylene ether) mixed with an inorganic material as an anion exchange membrane polymer satisfying the above-mentioned criteria have been developed. Although the above-mentioned conventional polymers have properties such as excellent thermal stability, they have low conductivity and alkali stability at high temperature and have low solubility as usual. Therefore, they are used for anion exchange membrane fuel cell, There was a limit.

Accordingly, there is a great demand for development of an anion exchange membrane having improved ionic conductivity, chemical stability, and heat resistance in addition to high solubility.

Patent Document 1: Korean Patent Laid-Open Publication No. 10-2013-0052973

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a polyetheretherketone copolymer having high ion conductivity, chemical stability and heat resistance, and an anion exchange membrane for fuel cells containing the same, .

In order to achieve the above object, the present invention provides a polyether ether ketone-based copolymer having a repeating unit represented by the following general formula (1).

In the above formulas,

X is a mole fraction (%) in a repeating unit, and x is an integer of 1 to 99. [

The present invention provides an anion exchange membrane of a fuel cell comprising a polyetheretherketone copolymer.

In order to accomplish the above-mentioned further object, the present invention provides a process for preparing a polyisocyanate comprising the steps of: A) dissolving and reacting a first monomer having an imidazole group, a second monomer of a bisphenol A series and a third monomer of difluorobenzophenone and a catalyst in a first solvent, To obtain a copolymer having a repeating unit represented by the formula (2);

B) adding a first solvent and a halogenated alkane compound to the copolymer obtained through the step A), and reacting;

C) precipitating a synthesized polyether ether ketone-based copolymer by adding a second solvent to the reaction solution obtained in the step B);

D) dissolving the precipitate obtained from step C) in a third solvent and forming a film therefrom;

상기 화학식에서,
상기 x는 반복단위 내 몰 분율(%)로, 상기 x는 1 내지 99의 정수이다.E) impregnating the membrane with a KOH solution, and a method for producing an anion exchange membrane of a fuel cell.
(2)

In the above formulas,
X is a mole fraction (%) in a repeating unit, and x is an integer of 1 to 99. [

The first monomer is characterized by being represented by the following formula (a).

(A)

The second monomer is characterized by being represented by the following formula (b).

[Formula b]

And the third monomer is represented by the following formula (c).

(C)

The catalyst is characterized by any one selected from the group consisting of sodium hydroxide, potassium hydroxide, lithium hydroxide, magnesium hydroxide, sodium carbonate, potassium carbonate and calcium carbonate.

Wherein the first solvent and the second solvent are methylbenzene or dimethylacetamide, and the second solvent is a mixed solvent of ether and ethanol.

Wherein the first monomer is contained in an amount of 5 to 20 mol% and the second monomer is contained in an amount of 80 to 95 mol% based on 100 mol% of the total amount of the first monomer and the second monomer.

And the third monomer is contained at a molar ratio of 1 to 1.5 times the total number of moles of the first monomer and the second monomer.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a copolymer of a polyetheretherketone series which has an imidazolium group introduced into a polyetheretherketone-based copolymer to improve not only solubility but also ionic conductivity, chemical stability and heat resistance, Ion conductivity, chemical stability and heat resistance, which were disadvantages of the anion exchange membrane used.

1 is a ¹ H-NMR spectrum of a monomer having an ammonium group prepared from Synthesis Example 1. FIG.
2 is a ¹ H-NMR spectrum of the first monomer having an imidazole group prepared from Synthesis Example 2. Fig.
3 is a ¹ H NMR spectrum of a polyether ether ketone-based copolymer having repeating units represented by the formula (1) prepared in Examples 2 to 5.
Fig. 4 is a photograph showing the actual state of each of the anion exchange membranes for fuel cells manufactured in Examples 1 to 5. Fig.
FIG. 5 is a graph showing a thermogravimetric analysis (TGA) result of each of the anion exchange membranes for fuel cells prepared in Examples 1 to 5. FIG.
Fig. 6 is a graph showing the water content (%) of each of the anion exchange membranes for fuel cells prepared in Examples 2 to 5 under various temperature conditions.
7 is a graph showing the ion exchange capacity (mmol / g) of each of the anion exchange membranes for fuel cells prepared in Examples 2 to 5 measured and measured.
FIG. 8 is a graph showing ion conductivity (S / cm) of each of the anion exchange membranes for fuel cells manufactured from Examples 1 to 4.

Hereinafter, the present invention will be described in more detail.

An aspect of the present invention relates to a polyether ether ketone-based copolymer having a repeating unit represented by the following formula (1).

[Chemical Formula 1]

In the above formulas,

X is a mole fraction (%) in a repeating unit, and x is an integer of 1 to 99. [

The average molecular weight of the polyetheretherketone-based copolymer having the repeating unit represented by the formula (1) is preferably 1000 to 2500.

The copolymer is characterized in that a monomer having an imidazolium group is introduced into a main chain of a copolymer of a polyetheretherketone series. The imidazolium group-containing monomer is obtained by adding an imidazolium group, which is an anion-exchange group, , Ion conductivity and solubility as well as the ion exchange ability can be improved.

The polyetheretherketone-based copolymer represented by the general formula (1) of the present invention has excellent ion-exchange capacity and improves mechanical properties by using a high-strength polyetheretherketone-based copolymer as a main chain, that is, a support Compared to other copolymers other than the above-mentioned structures, having a proper water content at a high temperature significantly lowers the brittleness and improves the strength, has a low membrane area resistance, has excellent ionic conductivity and increases the flexibility of the membrane, It is confirmed that the ion distribution is improved and the film is easy to form because of its excellent solubility in solvents.

Therefore, the copolymer of the present invention is useful for forming an anion exchange membrane for a fuel cell having an excellent solubility in a solvent, a low electric resistance, an improved ionic conductivity and an improved ion exchange capacity, mechanical properties, chemical properties, workability and heat resistance Lt; / RTI >

Another aspect of the present invention relates to an anion exchange membrane for fuel cells comprising a polyetheretherketone-based copolymer.

 Specifically, the present invention is directed to a fuel cell anion exchange membrane having a single membrane structure by applying a composition including a copolymer for an anion exchange membrane of the fuel cell onto a substrate such as Teflon and treating the same.

The anion exchange membrane preferably has a thickness of 90 to 110 占 퐉 because it must simultaneously satisfy the ion exchange capacity, heat resistance, and processability, that is, ease of manufacture.

More preferably, the polyetheretherketone-based copolymer containing the repeating unit represented by the above-mentioned formula (1) may have a mole fraction (%) of from 5 to 10 mol%, because the polyetheretherketone Based copolymer is excellent in both ion conductivity and ion exchange ability even under a high temperature condition, and at the same time, an excellent effect of physical strength and heat resistance characteristics can be obtained.

If x is more than 10 mole% in the polyetheretherketone-based copolymer containing the repeating unit represented by the above-mentioned formula (1), physical strength is remarkably low in forming an anion exchange membrane, It can be confirmed that the resistance is increased and the ionic conductivity is remarkably decreased by 2 times or more.

Specifically, the anion exchange membrane was analyzed by thermogravimetric analysis under a nitrogen gas stream, and it was found that the anion-exchange membrane had a very excellent thermal stability at which the deterioration of the backbone chain of the polyetheretherketone-based copolymer was started at 500 ° C or higher Respectively.

Also, the anion exchange membrane was measured for water content at high temperature (60 to 90 ° C) for 24 hours, and the result showed a low water content increase pattern. Specifically, in the polyetheretherketone-based copolymer containing the repeating unit represented by the above-mentioned formula (1), when x is in the range of 5-10 mol% or more, the water content is higher than 40% at a high temperature In the polyetheretherketone-based copolymer containing the repeating unit represented by the above formula (1), when the content of x is in the range of 5-10 mole%, the increase in the water content is only 20% at maximum , And that it has a low water content of 30% or less even at a high temperature.

As a result of measuring the anion exchange capacity of the anion exchange membrane of the present invention, it was confirmed that it had an excellent anion exchange capacity of 0.8 to 1.6 mmol / g, and the ion conductivity according to the temperature was also 0.05 to 0.3 S / cm, It can be confirmed that the anion exchange membrane of the Example 1 in which the diazolium group is not introduced is 5 times or more and 6 times or more superior than the anion exchange membrane of Example 1.

The present invention also provides a fuel cell comprising the anion exchange membrane.

The fuel cell comprising the anion exchange membrane may be, but is not limited to, an alkaline fuel cell (AFC) or a borohydride fuel cell (BFC). The fuel cell including the anion exchange membrane has an effect of reducing the thermodynamic voltage loss due to the difference in the pH value between the exchange membranes due to the thermal stability.

Another aspect of the present invention relates to a method for producing an anion exchange membrane for a fuel cell comprising the following steps.

A) A method for producing a copolymer having repeating units represented by formula (2) by dissolving and reacting a first monomer having an imidazole group, a second monomer of bisphenol A series, a third monomer of difluorobenzophenone, and a catalyst in a first solvent, Obtaining a coalescence;

B) adding a first solvent and a halogenated alkane compound to the copolymer obtained through the step A), and reacting;

C) precipitating a synthesized polyether ether ketone-based copolymer by adding a second solvent to the reaction solution obtained in the step B);

D) dissolving the precipitate obtained from step C) in a third solvent and forming a film therefrom;

E) impregnating the membrane with a KOH solution, which can be represented specifically by the following Reaction Scheme 3.

[Reaction Scheme 3]

In the above formula (3), x is an integer of 1 to 99.

First, the step A) is carried out by dissolving and reacting a first monomer having an imidazole group, a second monomer of a bisphenol A series, a third monomer of difluorobenzophenone, and a catalyst in a first solvent to obtain a compound represented by Formula 2 Lt; RTI ID = 0.0 > repeating < / RTI >

Here, the first monomer is preferably one represented by the following formula (a).

(A)

It is preferable that the second monomer is represented by the following formula (b).

[Formula b]

The third monomer is preferably one represented by the following formula (c).

(C)

It is preferable that the first monomer is contained in an amount of 5 to 20 mol% and the second monomer is contained in an amount of 80 to 95 mol% based on 100 mol% of the total amount of the first monomer and the second monomer. However, considering the effects of various ionic conductivities, mechanical properties, ion exchange capacity, solubility, and the like, as confirmed in Experimental Examples to be described later, the total number of moles of the first monomer and the second monomer is 100 mol% Most preferably 5 to 10 mol% of the first monomer and 90 to 95 mol% of the second monomer.

The reaction of step (A) may be carried out by reacting the -OH group present in the first monomer and the second monomer with the -F group present in the third monomer to produce a polyether ether ketone-based copolymer having a repeating unit represented by the formula (2) The third monomer should be contained at a molar ratio of 1 to 1.5 times the total number of moles of the first monomer and the second monomer, and preferably the molar ratio of the first monomer to the second monomer The third monomer is easy to prepare a polyether ether ketone-based copolymer having a repeating unit represented by the general formula (2) with a desired mole fraction to be contained in one mole.

The catalyst used in step A) may be any one selected from the group consisting of sodium hydroxide, potassium hydroxide, lithium hydroxide, magnesium hydroxide, sodium carbonate, potassium carbonate and calcium carbonate, , It is most preferable since it is possible to prepare a polyether ether ketone-based copolymer having a repeating unit represented by the general formula (2).

The catalyst may be mixed in an amount of 2 moles or more based on 1 mole of the entire mixture of the first monomer and the second monomer. If the amount of the catalyst is less than 2 moles based on 1 mole of the entire mixture of the first monomer and the second monomer, the content of the catalyst is low to form an incomplete reaction, and the total reaction time becomes long. .

The step A) is preferably carried out in the presence of a catalyst at a temperature ranging from 40 to 80 ° C.

A condensation reaction of the starting materials of step A) with the polyetheretherketone-based copolymer having the repeating unit represented by the formula (2) is carried out through the step (A), which is a polyether ether And acts as a precursor of a ketone-based copolymer.

In the step B) of the present invention, the first solvent and the halogenated alkane compound are added to the copolymer obtained through the step A) and reacted.

The first solvent used in the step B) is not particularly limited as long as it is a solvent used in the reaction performed in the step B), but it is preferable that the solvent is not reacted with the starting material, the intermediate and the material of the present invention, Do. For example, hexane, aliphatic hydrocarbon solvent including heptane; Aromatic hydrocarbon solvents including pyridine, quinoline, anisol, mesitylene, and xylene; aromatic hydrocarbons; Ketone-based solvents including methyl isobutyl ketone, 1-methyl-2-pyrrolidinone, cyclohexanone, and acetone. solvent); Ether-based solvents including tetrahydrofuran, isopropyl ether, and the like; An acetate-based solvent including ethyl acetate, butyl acetate, and propylene glycol methyl ether acetate; Alcohol-based solvents including isopropyl alcohol and butyl alcohol; Amide-based solvents including dimethylacetamide and dimethylformamide; Silicon-based solvent; And a mixture of these solvents is preferable, and dimethylacetamide or methylbenzene is more preferable.

The halogenated alkane compound is preferably selected from the group consisting of 1-iodomethane, 1-iodoethane, 1-iodopropane (1-iodoethane), 1- iodopropane, 1-iodobutane, 1-iodopentane, 1-iodohexane, 1-iodoheptane, 1-iodoctane, 1-iodononane, 1-iododecane, 1-iodododecane and 1-iodoctadecane ( 1-iodooctadecane).

The step B) is preferably carried out at 10 to 50 ° C, and the most preferably is carried out at a temperature of 30 ° C in terms of yield.

Through the above step B), a polyether ether ketone-based copolymer having a repeating unit represented by the general formula (3) is obtained.

The step C) is a step of precipitating a polyether ether ketone-based copolymer synthesized by adding a second solvent to the reaction solution obtained in the step B). That is, the second solvent is not particularly limited as long as it serves to solidify a polyether ether ketone-based copolymer having a repeating unit represented by the general formula (3) synthesized in the step B).

The second solvent is not particularly limited as long as it is a solvent used in the reaction carried out in step C), but it is preferable that the second solvent is excellent in solubility without reacting with the starting materials, intermediates and products of the present invention. For example, hexane, aliphatic hydrocarbon solvent including heptane; Aromatic hydrocarbon solvents including pyridine, quinoline, anisol, mesitylene, and xylene; aromatic hydrocarbons; Ketone-based solvents including methyl isobutyl ketone, 1-methyl-2-pyrrolidinone, cyclohexanone, and acetone. solvent); Ether-based solvents including tetrahydrofuran, isopropyl ether, and the like; An acetate-based solvent including ethyl acetate, butyl acetate, and propylene glycol methyl ether acetate; Alcohol-based solvents including isopropyl alcohol and butyl alcohol; Amide-based solvents including dimethylacetamide and dimethylformamide; Silicon-based solvent; And a mixture of the above-mentioned solvents, and more preferably a mixed solvent of ether and ethanol.

Next, the step D) is a step of dissolving the precipitate obtained in the step C) in a third solvent and forming a film therefrom.

Specifically, the method may be carried out by dissolving the precipitate obtained in the step C) in a third solvent to prepare a coating solution, applying the coating solution on a substrate and drying the coating solution, and may be carried out by a conventional method in the art , But is not limited thereto.

The film is characterized by being formed by spin coating, dip coating, cast coating or spray coating.

The substrate may be a glass plate.

The third solvent is not particularly limited as long as it is a solvent used in the reaction performed in step C), but it is preferable that the third solvent is excellent in solubility without reacting with the starting materials, intermediates and products of the present invention. For example, hexane, aliphatic hydrocarbon solvent including heptane; Aromatic hydrocarbon solvents including pyridine, quinoline, anisol, mesitylene, and xylene; aromatic hydrocarbons; Ketone-based solvents including methyl isobutyl ketone, 1-methyl-2-pyrrolidinone, cyclohexanone, and acetone. solvent); Ether-based solvents including tetrahydrofuran, isopropyl ether, and the like; An acetate-based solvent including ethyl acetate, butyl acetate, and propylene glycol methyl ether acetate; Alcohol-based solvents including isopropyl alcohol and butyl alcohol; Amide-based solvents including dimethylacetamide and dimethylformamide; Silicon-based solvent; And a mixture of the above-mentioned solvents, and most preferably dimethylformamide or dimethylacetamide.

 When the precipitate (including a polyether ether ketone-based copolymer having a repeating unit represented by the formula (3)) is dissolved in a third solvent, the concentration of the precipitate is 0.5 to 20% by weight and the concentration of the third solvent is 80 To 99.5% by weight. If the concentration of the precipitate is less than 0.5% by weight, it is difficult to uniformly form a coating layer which functions as an ion exchange membrane. If the concentration of the precipitate exceeds 20% by weight, It becomes too thick to cause deterioration of the performance of the fuel cell.

Finally, the step E) is a step of impregnating the membrane with the KOH solution. This is because the iodide (I-) group in the polyetheretherketone-based copolymer having the repeating unit represented by the formula (3) is replaced with the hydroxide (OH-) group to form a polyetheretherketone- (20 to 40 ° C) for 40 to 50 hours. The above-described ion-exchange membrane is preferably used as the ion exchange membrane.

The anion exchange membrane for a fuel cell produced by the method according to the present invention has excellent mechanical strength, chemical stability, durability and heat resistance, and high solubility and ion exchange capacity, even though a large amount of imidazolium group is introduced into an anion exchange group And an ionic conductivity improving effect.

Hereinafter, the present invention will be described in more detail with reference to Examples and the like, but the scope and content of the present invention can not be construed to be limited or limited by the following Examples. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the present invention as set forth in the following claims. It is natural that it belongs to the claims.

In addition, the experimental results presented below only show representative experimental results of the embodiments and the comparative examples, and the respective effects of various embodiments of the present invention which are not explicitly described below will be specifically described in the corresponding part.

Synthetic example  1. Third Amine group  ≪ / RTI >

A method for producing a tertiary amine-containing monomer (ADHDPE) is shown in the following reaction formula (1).

[Reaction Scheme 1]

 DHDPE (4,4'-dihydroxydiphenyl ether) was dissolved in ethanol, dimethylamine solution and formaldehyde solution were added, and the mixture was allowed to react at room temperature for 24 hours. The monomer having an ammonium group (Powder form; ADHDPE) was obtained by filtration followed by drying and recrystallization.

The monomer having a tertiary amine group (powder form; ADHDPE) produced through the above process could be confirmed by ¹ H NMR (FIG. 1). The integral ratio of the peaks shown in Fig. 1 is confirmed by the molar ratio of each component.

300MHz, Chloroform-d in a solvent ¹ H NMR was measured by δ = ppm is, 7.2 (s, 2 H, ArH), 6.62 (s, 2 H, ArH), 3.5 (s, 8 H; -CH 2 - N -), and2.32 (s, 24H; -N-CH 3). FT-IR: 3400 (OH), 3100 (aromatic CH), 1600-1475 (aromatic C = C), 1250 (aromatic CO) cm ^-1 .

Synthesis Example 2: Preparation of a first monomer having an imidazole group (Preparation of QIDHDPE0.

The method for producing the first monomer (QIDHDPE0) having an imidazole group represented by the formula (a) is shown in the following reaction formula (2).

[Reaction Scheme 2]

Dimethylbenzene was added to the monomer having tertiary amine group prepared in Synthesis Example 1 to dissolve it, 2-ethylimidazole was added, and the mixture was reacted at 140 ° C for 12 hours. The reaction solution in which the reaction has been completed is recovered and the unreacted material is removed by liquid-liquid extraction using a mixed solution of ethyl acetate and distilled water to obtain a first liquid phase reaction liquid having an imidazole group Monomer (QIDHDPE) was obtained.

The first monomer (QIDHDPE) having an imidazole group represented by the formula (a), which was produced through the above process, could be confirmed by ¹ H NMR (FIG. 2). The integral ratio of the peaks shown in Fig. 2 is confirmed by the molar ratio of each component.

≪ ¹ > H NMR, measured at [delta] = ppm in a 300 MHz, DMSO-d6 solvent, ^{1 HNMR: 7.2 (s, 4H} , ArH), 7.1 (s, 4H, Im-ArH), 6.9 (s, 4H, Im-ArH), 5.1 (s, 8H; -CH 2 -N -), 2.7 ( s, 2H; -OH), 2.32 (s, 8 H; -CH 2 -), 1.42 (s, 12 H; -CH 3). FT-IR: 3400 (OH), 3100 (aromatic CH), 1600-1475 (aromatic C = C), 1268-1220 (CN), 1250 (aromatic CO) cm ^-1 .

Example  1 to 5. < / RTI > Polyetheretherketone-based  Preparation of Copolymers.

A method for producing a polyether ether ketone-based copolymer having a repeating unit represented by the formula (1) is shown in the following reaction formula (3).

[Reaction Scheme 3]

(QIDHDPE), bisphenol-A (BPA), difluorobenzophenone (third monomer) having an imidazole group and represented by the formula [a] (DFB), wherein X represents the molar fraction of the first monomer (QIDHDPE) having an imidazole group.

First, a first monomer (QIDHDPE) having an imidazole group and a bisphenol-A (BPA), a bisphenol-A (BPA), and a difluorobenzophenone (DFB) were mixed in an appropriate amount, and K ₂ CO ₃ catalyst was added thereto. Through the reaction, a polyether ether ketone-based copolymer having a repeating unit represented by the general formula (2) was prepared. The mixing ratios of the monomers are shown in Table 1 below.

In order to imidazolium halogenide the imidazole group in the polyetheretherketone-based copolymer having the repeating unit represented by the formula (2), the above mixture (the polyetheretherketone-series copolymer having the repeating unit represented by the formula (2) ) Was dissolved in dimethylacetamide (DMAC), iodomethane was added, and a polyether ether ketone-based copolymer having a repeating unit represented by the formula (3) formed through the reaction was dissolved in ether ether, and ethanol to precipitate (polymerize). This was collected by filtration and washed with water to obtain a polyether ether ketone-based copolymer having a repeating unit represented by the formula (3).

Next, a polyether ether ketone-based copolymer having a repeating unit represented by the formula (3) obtained through the above-mentioned process was dissolved in a dimethylforamide (DMF) solvent at a concentration of 3 wt% The applied solution was irradiated with an IR lamp and dried to form a film.

Thereafter, in order to replace the iodide (I-) group in the polyetheretherketone-based copolymer having the repeating unit represented by the general formula (3) with the hydroxide (OH-) group, the dried membrane was immersed in a 1 mole concentration of KOH For 48 hours to prepare an anion exchange membrane for a fuel cell comprising a polyether ether ketone-based copolymer having a repeating unit represented by the following formula (1).

The polyether ether ketone-based copolymer (Example 2-5) having the repeating unit represented by the formula (1) produced through the above process was confirmed by ¹ H NMR (FIG. The integral ratio of the peak shown in Fig. 3B is confirmed by the molar ratio of each component shown in Fig. 3A.

300MHz, in DMSO-d6 solvent ¹ H NMR was measured by δ = ppm has, 7.76 (s, 8H; ArH ), 7.24 (s, 4H; ArH), 7.02 (s, 12H; ArH), 6.91 (s, 4H; Im-ArH), 6.75 (s, 4H; Im-ArH), 4.06 (s, 8H; -CH 2 -N-), 3.36 (s, 8H-CH 2 -), 1.60 (s, 6H; - _{CH 3), 1.12 (s,} 12H -CH 3). FT-IR: 3100 (aromatic CH), 1685 (C = O), 1600-1475 (aromatic C = C), 1268-1220 (CN), 1250 (aromatic CO) cm ^-1 .

division Mol% (mole) The mole ratio of the third monomer to (a) + (b) (mole of the added third monomer The molar ratio of catalyst to (a) + (b)
(1: 2.1)

catalyst The first monomer (a) The second monomer (b) (a) + (b) Example 1 - 100 (1) 100 1: 1 (1 mole) K ₂ CO ₃ (2.1 mole) Example 2 5 (0.05) 95 (0.95) 100 1: 1 (1 mole) K ₂ CO ₃ (2.1 mole) Example 3 10 (0.10) 90 (0.90) 100 1: 1 (1 mole) K ₂ CO ₃ (2.1 mole) Example 4 15 (0.15) 85 (0.85) 100 1: 1 (1 mole) K ₂ CO ₃ (2.1 mole) Example 5 20 (0.20) 80 (0.80) 100 1: 1 (1 mole) K ₂ CO ₃ (2.1 mole)

Fig. 4 is a photograph showing the actual state of each of the anion exchange membranes for fuel cells manufactured in Examples 1 to 5. Fig.

As shown in FIG. 4, it can be seen that the anion exchange membranes for fuel cells prepared in Examples 1 to 5 are all excellent in transparency. Among them, the anion exchange membranes prepared in Examples 2 and 3 have excellent transparency Respectively.

FIG. 5 is a graph showing a thermogravimetric analysis (TGA) result of each of the anion exchange membranes for fuel cells prepared in Examples 1 to 5. FIG.

5 is a graph showing the anion exchange membranes prepared in Examples 1 to 5 by applying heat in a temperature range of 25 to 750 ° C under a nitrogen gas flow and analyzing mass changes therefrom. The prepared anion exchange membrane has a primary decomposition temperature indicating a decrease in imidazolium group at 250 to 400 ° C and deterioration of the backbone chain in the polyetheretherketone copolymer from 500 ° C Respectively.

On the other hand, the anion exchange membrane prepared from Example 1 containing a polyether ether ketone-based copolymer to which the imidazolium group was not introduced showed a rapid decrease in weight at around 500 ° C without the primary decomposition temperature.

As a result, it can be seen that the anion exchange membrane for a fuel cell comprising the polyetheretherketone-based copolymer of the present invention is remarkably excellent in thermal stability.

Fig. 6 is a graph showing the water content (%) of each of the anion exchange membranes for fuel cells prepared in Examples 2 to 5 under various temperature conditions.

The sample (anion exchange membrane) was immersed in distilled water at different temperatures (25 ° C, 40 ° C, 60 ° C, and 80 ° C), taken out after 24 hours, and measured for water content.

As shown in FIG. 6, the moisture content of the anion exchange membranes for fuel cells prepared in Examples 2 to 5 was analyzed. As a result, it was found that the water content increased as the imidazolium groups introduced into the copolymer increased.

Particularly, the anion exchange membranes for fuel cells produced from Examples 2 and 3 have a water content at a high temperature (60-80 ° C), and the brittleness is greatly lowered to improve the strength and the low membrane area resistance, The flexibility of the membrane is increased, the ion distribution of the whole membrane is improved, and the solubility in the solvent is high, so that it is easy to form the membrane.

Specifically, the anion exchange membranes for fuel cells prepared in Examples 2 and 3 show a water content variation of only 20% at a temperature and a low water content of 30% or less even at a high temperature. On the contrary, in Examples 4 and 5 It is found that the anion exchange membrane for fuel cell has a water content of 40% or more at a high temperature and a variation of water content according to temperature is also about 40-50% at maximum.

7 is a graph showing the ion exchange capacity (mmol / g) of each of the anion exchange membranes for fuel cells prepared in Examples 2 to 5 measured and measured. Equivalent (%) in the graph represents mol% in which the first monomer is contained, based on 100 mol% of the total number of moles of the first monomer and the second monomer. Examples 2, 3, 4 and 5 are in order.

As shown in FIG. 7, it was confirmed that it had an excellent anion exchange capacity of 0.8 to 1.6 mmol / g.

That is, it can be seen that the ion exchange capacity is also increased with the increase of the imidazolium group introduction amount, and the anion exchange membranes for fuel cells manufactured from Examples 2 to 5 have no significant difference in ion exchange capacity, The higher was the anion exchange membrane for fuel cells (1.54 mmol / g) prepared from Example 5.

FIG. 8 is a graph showing ion conductivity (S / cm) of each of the anion exchange membranes for fuel cells manufactured from Examples 1 to 4.

As shown in FIG. 8, the anion exchange membranes for fuel cells prepared in Examples 2 and 3 have remarkably excellent ion conductivity at both low temperature and high temperature, and this shows that the anions for fuel cells prepared in Example 1 in which imidazolium groups are not introduced It is more than 2 times higher than basic membrane and 6 times higher than exchange membrane.

In addition, the anion exchange membrane for fuel cells prepared in Example 4 has an ion conductivity similar to that of the anion exchange membrane for fuel cells prepared in Example 1. This is because when the anion exchange membrane is formed, its physical strength is remarkably low, The ionic conductivity of the anion exchange membrane for fuel cells prepared in Examples 2 and 3 is remarkably lower than that of the anion exchange membrane for fuel cells.

Claims (10)

1. A polyether ether ketone-based copolymer having a repeating unit represented by the following formula (1).
[Chemical Formula 1]

In the above formulas,
X is a mole fraction (%) in a repeating unit, and x is an integer of 1 to 99. [ An anion exchange membrane of a fuel cell comprising a polyetheretherketone-based copolymer according to claim 1. A) A method for producing a copolymer having repeating units represented by formula (2) by dissolving and reacting a first monomer having an imidazole group, a second monomer of bisphenol A series, a third monomer of difluorobenzophenone, and a catalyst in a first solvent, Obtaining a coalescence;
B) adding a first solvent and a halogenated alkane compound to the copolymer obtained through the step A), and reacting;
C) precipitating a synthesized polyether ether ketone-based copolymer by adding a second solvent to the reaction solution obtained in the step B);
D) dissolving the precipitate obtained from step C) in a third solvent and forming a film therefrom;
E) impregnating the membrane with a KOH solution.
(2)

In the above formulas,
X is a mole fraction (%) in a repeating unit, and x is an integer of 1 to 99. [ The method of claim 3,
Wherein the first monomer is represented by the following formula (a).
(A)

The method of claim 3,
Wherein the second monomer is represented by the following formula (b).
[Formula b]

The method of claim 3,
Wherein the third monomer is represented by the following formula (c).
(C)

The method of claim 3,
Wherein the catalyst is any one selected from the group consisting of sodium hydroxide, potassium hydroxide, lithium hydroxide, magnesium hydroxide, sodium carbonate, potassium carbonate and calcium carbonate. The method of claim 3,
Wherein the first solvent and the second solvent are methylbenzene or dimethylacetamide,
Wherein the second solvent is a mixed solvent of ether and ethanol. The method of claim 3,
Wherein the first monomer is contained in an amount of 5 to 20 mol% and the second monomer is contained in an amount of 80 to 95 mol% based on 100 mol% of the total amount of the first monomer and the second monomer. Of the anion exchange membrane. The method of claim 3,
Wherein the third monomer is contained at a molar ratio of 1 to 1.5 times the total number of moles of the first monomer and the second monomer.

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