KR20080045881A - Sulphonated multi block copolymer synthesized by one-step polymerization and electrolyte membrane using the same - Google Patents

Abstract

A method for preparing sulfonated multi block copolymers is provided to improve productivity by block-copolymerizing hydrophilic blocks and hydrophobic blocks continuously in a reactor without going through a work-up step. A method for preparing sulfonated multi block copolymers includes the steps of: (a) charging a bisphenol-based monomer or aromatic dihalogen-based monomer, a bisphenol-based monomer having an acid substituent or aromatic dihalogen-based monomer having an acid substituent, a carbonate anhydride catalyst, and a first organic solvent into a reactor, and performing polymerization to prepare hydrophilic blocks; and (b) putting a bisphenol-based monomer, an aromatic dihalogen-based monomer, a carbonate anhydride catalyst, and a second organic solvent into the reactor containing the prepared hydrophilic blocks and the first organic solvent, and performing polymerization to prepare hydrophobic blocks and to prepare multi block copolymers at the same time.

Description

Method for producing sulfonated multi-block copolymer {SULPHONATED MULTI BLOCK COPOLYMER SYNTHESIZED BY ONE-STEP POLYMERIZATION AND ELECTROLYTE MEMBRANE USING THE SAME}

1 is a result of measuring the hydrogen ion conductivity of the sulfonated multi-block copolymer prepared according to an embodiment of the present invention and Nafion 115.

The present invention relates to a method for producing a sulfonated multi-block copolymer, and more particularly, sulfonated multi-block air, characterized in that the block copolymerization of the hydrophilic block and the hydrophobic block continuously in one reactor without a work-up process It relates to a method for producing the coalescence.

A fuel cell is an energy conversion device that converts chemical energy generated by the electrochemical reaction of fuel and oxygen directly into electrical energy. It is an eco-friendly feature with high energy efficiency and low emission of pollutants. It is being researched and developed a lot as a next generation energy source that can be applied to power supply of electric / electronic products.

The type of fuel cell is a polymer electrolyte fuel cell (PEFC) used at a temperature of 40 to 80 ℃, an alkaline electrolyte fuel cell (AFC) used at a temperature of 65 to 220 ℃. Phosphoric Acid Fuel Cell (PAFC) applied at around 200 ℃, Molten Carbonate Fuel Cell (MCFC) operating at 650 ℃ and solid oxide fuel cell operating at over 600 ℃ (SOFC: Solid Oxide Fuel Cell), etc., depending on the electrolyte used, the operating temperature of the fuel cell and the materials of the components are different.

The double polymer electrolyte fuel cell (PEFC) has been spotlighted as a portable, vehicle, and home power supply due to its low operating temperature, elimination of leakage due to the use of a solid electrolyte, and fast driving. In addition, it is a high-output fuel cell with a higher current density than other fuel cells, which operates at temperatures below 100 ° C, has a simple structure, fast start-up and response characteristics, and excellent durability, and can be miniaturized with high power density. As a result, research into portable fuel cells continues. The polymer electrolyte fuel cell is a polymer electrolyte membrane fuel cell (PEMFC) for supplying hydrogen gas and a direct methanol fuel cell (DMFC) for supplying liquid fuel according to a fuel supply method for the anode. Can be divided into

In general, an electrolyte membrane used in a polymer electrolyte fuel cell serves as a separator for hydrogen ions generated by oxidation of fuel at the anode to move to the cathode, as well as to electrically separate the anode and the cathode and to isolate the two electrodes. Do it. Therefore, the electrolyte membrane used in the polymer electrolyte fuel cell must have high hydrogen ion conductivity, electrochemically stable, and have mechanical strength as a separator separating the two electrodes in order to move large amounts of hydrogen ions quickly, and at operating temperature It should have thermal stability of. In addition, the thin film of the polymer should be possible for the preparation of the polymer electrolyte membrane, and should have chemical stability against methanol used as fuel.

Currently, the most commonly used electrolyte membrane in polymer electrolyte fuel cells is Nafion (perfluorinated sulfonic acid polymer), a product of Du Pont, USA. It is a perfluorinated polymer electrolyte, which has ion conductivity, chemical stability, and ion selectivity. There is an advantage that the back is excellent. However, fluorinated polyelectrolyte membranes are not suitable for industrial use due to their high price, while their performance is high, methanol has high methanol crossover through the polymer membrane, and loses the water contained in the membrane at a high temperature of 100 ° C. or higher. As a result, the efficiency of the polymer membrane is reduced. Accordingly, research on hydrocarbon ion exchange membranes that can compete in terms of price is being actively conducted.

US Patent No. 2004-186262 discloses a method for producing a multi-block copolymer polymer electrolyte membrane in which a hydrophobic block made of hydrocarbons and a hydrophilic block having ion conductivity made of hydrocarbons are alternately connected. It is disclosed. Due to the low solubility of the multi-block copolymer, a thin film was prepared by converting a -SO ₃ K type copolymer into -SO ₂ Cl using thionyl chloride (SOCl ₂ ) during thin film preparation, and then again- Hydrolysis was performed with a SO ₃ H-type polymer thin film to impart hydrogen ion conductivity to the polymer thin film. However, the method has a complicated manufacturing process, and although the ion conductive polymer thin film is manufactured from the multi-block copolymer, there is a problem that the mechanical integrity of the polymer thin film does not reach the level required for driving the fuel cell.

Korean Patent No. 10-2004-0110487 discloses a method for producing a branched and sulfonated multi block copolymer polymer electrolyte membrane in which a hydrophobic block and a hydrophilic block made of hydrocarbons are alternately connected. It is disclosed about. Although the above method suggests a method for preparing a polymer electrolyte membrane having suitable mechanical and chemical properties and excellent ion conductivity, there is a problem in that the synthesis process of the multi-block copolymer is somewhat cumbersome.

The technical problem to be achieved by the present invention is to provide a method for producing a sulfonated multi-block copolymer that can be produced by continuously producing in one reactor without undergoing a work-up process.

In order to achieve the above object, the present invention

The present invention

a) preparing a hydrophilic block by adding a bisphenol monomer or an aromatic dihalogen monomer, a bisphenol monomer having an acid substituent or an aromatic dihalogen monomer having an acid substituent, a carbonate anhydride catalyst and an organic solvent in a reactor; And

b) in the reactor comprising the prepared hydrophilic block and the organic solvent, a bisphenol-based monomer, an aromatic dihalogen-based monomer, a carbonate anhydride catalyst and an organic solvent are added and polymerized to prepare a hydrophobic block, while at the same time multi-block copolymer Preparing a; It provides a method for producing a sulfonated multi-block copolymer comprising a.

In addition, a) adding a bisphenol-based monomer, an aromatic dihalogen-based monomer, a carbonate anhydride catalyst and a first organic solvent in a reactor to prepare a hydrophobic block; And

b) a bisphenol-based monomer or an aromatic dihalogen-based monomer, a bisphenol-based monomer having an acid substituent or an aromatic dihalogen-based monomer having an acid substituent, or a carbonate in the reactor including the prepared hydrophobic block and the first organic solvent Adding and polymerizing an anhydride catalyst and a second organic solvent to prepare a hydrophilic block and simultaneously preparing a multi-block copolymer; It provides a method for producing a sulfonated multi-block copolymer comprising a.

The present invention also provides a method for producing a branched sulfonated multiblock copolymer by adding a brancher in preparing the hydrophilic block or the minority block.

The present invention also provides a hydrotreated sulfonated multiblock copolymer, which is prepared by adding an acid solution to a sulfonated multiblock copolymer to replace the sulfonate with sulfonic acid.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

The present invention relates to a method for preparing a sulfonated multi-block copolymer, in which a solvent prepared for powdering a previously prepared block is polymerized after polymerizing a branched hydrophilic block and a branched hydrophobic block. Without the process of separating and drying the block (hereinafter, referred to as a work-up process), the copolymerization of the hydrophilic block and the hydrophobic block directly in a reactor to maintain the mechanical density of the thin film more simply Minority blocks and hydrophilic blocks that impart ion conductivity to the thin film create alternating chemical bonds.

The sulfonated multiblock copolymer may be prepared by the following methods, but the following production methods are merely examples for preparing the sulfonated multiblock copolymer of the present invention, and the preparation may be performed in the following methods. Of course, it is not limited.

That is, the sulfonated multiblock copolymer may be a sulfonated multiblock copolymer or a branched sulfonated multiblock copolymer composed of a repeating unit represented by the following Formula 1 or Formula 2.

[Formula 1]

[Formula 2]

In the formula of Formula 1 or 2,

,

,

,

,

,

,

,

,

,

,

,

, 또는

이고(여기서, R은 -NO₂ 또는 -CF₃임),A, X, and Y are each independently

,

,

,

,

,

,

,

,

,

,

,

, or

Where R is -NO ₂ or -CF ₃ ,

,

,

,

,

,

, 또는

이고(여기서, Q는 -SO₃H, -SO₃ ^-M⁺, -COOH, -COO^-M⁺, -PO₃H₂, -PO₃H^-M⁺, 또는 -PO₃ ^2-2M⁺이며, M은 Na 또는 K임), Z is

,

,

,

,

,

, or

And (wherein, Q is ^{_{-SO 3 H, -SO 3 - M}} +, -COOH, -COO - M +, -PO 3 H 2, -PO 3 H - M +, or -PO ₃ ^2- 2M ^+, and , M is Na or K),

,

,

, 또는

이고,B is

,

,

, or

ego,

G is X, G 'is Z,

b / a is 0 <b / a <1, d / c is 0 <d / c <1,

1 ≦ m <100 and 1 ≦ n <100.

The present invention is prepared by adding a bisphenol-based monomer or an aromatic dihalogen-based monomer, a bisphenol-based monomer having an acid substituent or an aromatic dihalogen-based monomer having an acid substituent, a carbonate anhydride catalyst and a first organic solvent to prepare a hydrophilic block. Without going through an up process, a bisphenol-based monomer, an aromatic dihalogen-based monomer, a carbonate anhydride catalyst, and a second organic solvent may be added and polymerized to prepare a hydrophobic block and at the same time prepare a multi-block copolymer.

In addition, the present invention is prepared by adding a bisphenol-based monomer, aromatic dihalogen-based monomer, carbonate anhydride catalyst and the first organic solvent in the reactor to produce a hydrophobic block, without going through a work-up process, immediately bisphenol-based monomer or aromatic dihalogen A hydrophilic block may be prepared by adding and polymerizing a monomer, a bisphenol monomer having an acid substituent, or an aromatic dihalogen monomer having an acid substituent, a carbonate anhydride catalyst, and a second organic solvent to prepare a multiblock copolymer.

In the above production method, a hydrophilic block or a hydrophobic block may be prepared by further adding a brancher in the step of preparing a hydrophilic block or a hydrophobic block to prepare a branched sulfonated multiblock copolymer.

The bisphenol-based monomers or aromatic dihalogen-based monomers used in the production methods may be 4,4'-difluorobenzophenone (4,4'-difluorobenzophenone), bis (4-fluorophenyl) sulfone (bis ( 4-fluorophenyl) sulfone), 2,2-bis (4-hydroxyphenyl) hexafluoropropane (2,2-bis (4-hydroxyphenyl) hexafluoropropane), or 4,4'-biphenol (4,4- biphenol) and the like.

As the bisphenol-based monomer having one or more acid substituents in the phenyl ring or the aromatic dihalogen-based monomer having one or more acid substituents in the phenyl ring, hydroquinonesulfonic acid potassium salt, 2,7- Dihydroxynaphthalene-3,6-disulfonic acid disodium salt (2,7-dihydroxynaphthalene-3,6-disulfonic acid disodium salt), 1,7-dihydroxynaphthalene-3-sulphonic acid monosodium salt ( 1,7-dihydroxynaphthalene-3-sulfonic acid monosodium salt), 2,3-dihydroxynaphthalene-6-sulfonic acid monosodium salt, potassium 5,5 '-Carnobylbis (2-fluorobenzene sulfonate) (potassium 5,5'-carnobylbis (2-fluorobenzene sulfonate)), or potassium 2,2-[9,9-bis (4-hydroxyphenyl) flu Orene] sulfonate (potassium 2,2 '-[9,9-bis (4-hydroxyphenyl) fluorene] sulfonate) and the like. Dual potassium 5,5'-carnobylbis (2-fluorobenzene sulfonate) converts 4,4'-difluorobenzophenone and 4,4'-difluorodiphenyl sulfone into fuming sulfuric acid. It can be prepared by direct sulfonation, and potassium 2,2 '-[9,9-bis (4-hydroxyphenyl) fluorene] sulfonate is 9,9-bis (4-hydroxyphenyl) Fluorene can be prepared by sulfonating directly with chlorosulfuric acid (CIHSO ₄ ).

In addition, in preparing the sulfonated multi-block copolymer, the monomer for preparing the hydrophilic block may be dissolved in an organic solvent together with the carbonate anhydride (or the monomer for preparing the hydrophobic block may be first dissolved), and then the mixture may be dissolved. Stir at 140-150 ° C. for 3-5 hours, remove the azeotrope from the mixture, and then react at 150-190 ° C. for 6-24 hours.

The carbonate anhydride is used as a catalyst, it is possible to use a common carbonate anhydride, preferably potassium carbonate (K ₂ CO ₃ ) is preferably used.

The organic solvent is not particularly limited as long as it can dissolve the reactants and the product well, in particular, N, N'-dimethylacetamide (DMAc), N-methylpyrrolidone (N-methyl pyrrolidone, NMP), dimethyl sulfoxide (DMSO), or N, N-dimethylformamide (N, N-dimethylformamide, DMF) or the like is preferably used. In particular, in the preparation of sulfonated multiblock copolymers, N, N'-dimethylacetamide (DMAc), N-methylpyrrolidone (NMP), dimethyl sulfoxide (dimethyl sulfoxide, DMSO), or N, N-dimethylformamide (NMF) as a single solvent, as well as N-methyl pyrrolidone (NMP) and dimethyl sulfoxide (dimethyl It is also possible to use a double solvent by combination of sulfoxide, DMSO).

In addition, the branch is introduced to prepare a branched sulfonated multi-block copolymer directly constitutes the main chain of the sulfonated multi-block copolymer, [3,5-bis (4-fluorobenzoyl) phenyl] ( 4-fluorophenyl) methanone (3,5-bis (4-fluorobenzoyl) phenyl) (4-fluorophenyl) methanone), [3,5-bis (4-fluorosulfonyl) phenyl] (4-fluoro Phenyl) methanone ([3,5-bis (4-fluorosulfonyl) phenyl] (4-fluorophenyl) methanone), (3,5-difluoro-4'-fluorobenzophenone) (3,5-difluoro- 4'-fluorobenzophenone) or (3,5-difluoro-4'-fluorophenyl) sulfone ((3,5-difluoro-4'-fluorophenyl) sulfone) and the like can be used. Among the [3,5-bis (4-fluorobenzoyl) phenyl] (4-fluorophenyl) methanone, 1,3,5-benzenetricarbonyltrichloride (1,3,5-benzenetricarbonyltrichloride), aluminum Aluminium chloride and fluorobenzene may be prepared by a Friedel-crafts reaction, and other structured blenders may also be prepared by a similar Friedel-Craft reaction.

The temperature of the mixture is then lowered to 60 ° C. followed by additional fractional blocks (or hydrophilicity).

Monomers for the preparation of blocks) are added to the organic solvent together with carbonate anhydride.

In this case, the additional organic solvent may be the same as the previously used organic solvent. After stirring the mixture at 140-150 ° C. for 3-5 hours, the azeotrope with toluene or benzene is removed via a dean-stark trap.

At this time, the distilled azeotrope is removed until it does not exit through the Dean-Stark trap.

After completely removing the azeotrope as described above, the reaction mixture is allowed to react with stirring at 150-190 ° C. for 6-24 hours.

After completion of the reaction, the reaction product is added directly to deionized water or methanol, or the reaction product is diluted by addition of deionized water or methanol, filtered to remove salts from the reaction product, and then the filtrate is removed from the reaction product. Precipitate in deionized water. The sulfonated multiblock copolymer can then be prepared by filtration and washing the precipitate several times with hot deionized water (˜80 ° C.) and methanol.

The weight average molecular weight of the hydrogen block may be 1,000 to 500,000 (g / mol), and the weight average molecular weight of the hydrophilic block may be 1,000 to 500,000 (g / mol).

In another aspect, the present invention Q is _{^{-SO 3 - M +, -COO -}} M +, -PO 3 H - M +, or -PO ₃ ^2- 2M ⁺ of the sulfonated multi comprised of the repeating unit represented by the formula (1) Hydrogenated sulfonated multiblock copolymers can be prepared by adding an acid solution to the block copolymer to replace the sulfonate with sulfonic acid.

That is, the above prepared sulfonated multiblock copolymer is Q is _{^{-SO 3 - M +, -COO -}} M +, -PO 3 H - a sulfonated salt when M ^+, or -PO ₃ ^2- 2M ⁺ Therefore, a hydrochloric acid or sulfuric acid solution is added to the copolymer in the form of sulfonate salt to replace the sulfonate with sulfonic acid, and then prepared as a polymer electrolyte membrane. At this time, the acid solution is preferably treated for 1 to 24 hours in a sulfonated multi-block copolymer at a concentration of 0.5 to 10 M at a temperature of 25 ~ 80 ℃.

The sulfonated multiblock copolymer electrolyte membrane can be prepared from the hydrotreated sulfonated multiblock copolymer, and the hydrotreated sulfonated multiblock copolymer is dissolved in a solvent, preferably the concentration of the sulfonated copolymer solution. Is about 20% (w / v), and is then prepared by casting a solution, preferably by casting on a glass plate.

As the solvent, a conventional organic solvent may be used, and specifically, the same solvent as that described in the preparation of the sulfonated block copolymer may be used.

The casting can be carried out by a conventional method, it is preferable to perform so that the thickness of the electrolyte membrane by a film applicator to be several tens to several hundred ㎛.

In addition, the sulfonated copolymer electrolyte membrane cast as described above is to dry the solvent in a vacuum oven to prepare a sulfonated multi-block copolymer electrolyte membrane in the form of film, wherein the drying is gradually raised to a temperature from room temperature to 80 ℃ 24 Dry for hours and further dry at 120 ° C. for 24 hours.

Hereinafter, preferred examples are provided to help understanding of the present invention, but the following examples are merely to illustrate the present invention, and the scope of the present invention is not limited to the following examples.

EXAMPLE

Example 1 Preparation of Hydrotreated Branched Sulfonated Multiblock Copolymer

In a 2 L round flask equipped with a dean-stark device and a condenser, 23.408 g of 4,4'-difluorobenzophenone, 23.983 g of hydroquinonesulphonic acid potassium salt and [3,5-bis] Add 0.983 g of (4-fluorobenzoyl) phenyl] (4-fluorophenyl) methanone and use 29.040 g of potassium carbonate in a nitrogen atmosphere using 150 mL of dimethyl sulfoxide (DMSO) and 200 mL of benzene. Was used to initiate the reaction.

The reaction mixture was then stirred for 4 hours in an oil bath at 140 ° C. to remove the azeotrope by adsorbing the azeotrope to the molecular sieves of the Dean-Stark apparatus while the benzene was refluxed, and then the reaction temperature was decreased. It heated up at 180 degreeC and made it polycondensate for 20 hours.

After the reaction was completed, the temperature of the reactant was reduced to 60 ° C., and 5.490 g of 4,4′-difluorobenzophenone, 11.045 g of 9,9-bis (4-hydroxyphenyl) fluorene, and [ Add 0.246 g of 3,5-bis (4-fluorobenzoyl) phenyl] (4-fluorophenyl) methanone and use potassium carbonate in a nitrogen atmosphere using 100 mL of dimethyl sulfoxide (DMSO) and 200 mL of benzene. The reaction was restarted using 8.712 g as catalyst.

The reaction mixture was then stirred for 4 hours in an oil bath again at a temperature of 140 ° C. to remove the azeotrope by adsorbing the azeotrope to the molecular sieves of the Dean-Stark apparatus while refluxing the benzene, followed by reaction temperature. The temperature was raised to 180 ° C and polycondensation reaction was carried out for 20 hours.

The reaction was then cooled to room temperature and 300 mL of dimethyl sulfoxide (DMSO) was added to dilute the reaction. The diluted reaction was poured into excess methanol to separate the copolymer from the solvent, followed by filtration. The copolymer was dried in a vacuum oven at 80 ° C. for at least 12 hours to prepare a branched sulfonated multiblock copolymer in which hydrophobic blocks and hydrophilic blocks were alternately chemically bonded.

10 g of the branched sulfonated multi-block copolymer prepared above was added to an aqueous 10% (w / V) sulfuric acid solution, followed by stirring at 80 ° C. for 4 hours to replace the sulfonate in the copolymer with sulfonic acid. Washed and filtered repeatedly with distilled water until the neutral, and the filtered sulfonic acid type sulfonated multiblock copolymer was dried in a vacuum oven at 80 ° C. for 12 hours to prepare a hydrogenated branched sulfonated multiblock copolymer. It was.

Example 2 Preparation of Hydrotreated Branched Sulfonated Multiblock Copolymer

In Example 1, both reactions using N-methyl pyrrolidone (NMP) instead of dimethyl sulfoxide (DMSO) used as a solvent in the hydrophilic block and hydrophobic block preparation reaction. A hydrogenated branched sulfonated multiblock copolymer was prepared in the same manner as in Example 1 except that.

Example 3 Preparation of Hydrotreated Branched Sulfonated Multiblock Copolymer

In Example 1, in place of dimethyl sulfoxide (DMSO) used as a solvent in the hydrophilic block and hydrophobic block reaction, N-methyl pyrrolidone (N-methyl pyrrolidone, NMP) was subjected to the same method as Example 1 except that dimethyl sulfoxide (DMSO) was used in the next hydrophobic block preparation to prepare a hydrotreated branched sulfonated multi-block copolymer.

Examples 4-6. Preparation of Branched Sulfonated Multiblock Copolymer Electrolyte Membranes

5 g of each of the hydrotreated branched sulfonated multiblock copolymers prepared in Examples 1 to 3 were dissolved in 45 g of N, N-dimethylacetamide, and then the solution was subjected to a BORU glass filter (pore size 3). Filtration removed dust and the like. A vacuum of 10% (w / V) of the filtrate was simultaneously heated to 120 ° C. to remove N, N-dimethylformamide in the filtrate, thereby preparing a solution of about 20% (w / V).

Pour the solution onto a PYREX glass substrate, adjust the thickness of the copolymer solution on the glass plate with a film applicator, and dry the copolymer solution on the glass plate for at least 12 hours in a vacuum oven at 80 ° C. A fonned multiblock copolymer electrolyte membrane was prepared.

Using the branched sulfonated multiblock copolymer electrolyte membranes prepared in Examples 4 to 6, ion exchange capacity (IEC), hydrogen ion conductivity, and methanol permeability were measured in the following manner.

A) IEC

After completely drying the branched sulfonated multiblock copolymer electrolyte membranes prepared in Examples 4 to 6, each 0.5 g of water was hydrated in ultrapure water at 100 ° C. for 2 hours and then immersed in 100 mL of supersaturated NaCl solution for at least one day. Ion (H ⁺ ) was replaced with sodium ion (Na ⁺ ). The substituted hydrogen ions (H ⁺ ) were titrated with 0.1 N NaOH standard solution to measure the number of moles of sufonic acid per gram of electrolyte membrane. IEC value of the polymer membrane was calculated according to Equation 1 below, and the results are shown in Table 1 below. At this time, the IEC value of Nafion 115 manufactured by DuPont was used as comparison data.

[Equation 1]

division IEC (meq./g) Walking properties Example 4 1.43 Transparent, excellent mechanical strength Example 5 1.41 Transparent, somewhat good mechanical strength Example 6 1.48 Transparent, somewhat good mechanical strength Nafion 115 0.91 Transparent, excellent mechanical strength

Through Table 1, it was confirmed that the branched sulfonated multi-block copolymer electrolyte membranes of Examples 4 to 6 prepared according to the present invention showed higher or similar IEC than Nafion used in the conventional polymer membrane.

B) hydrogen ion conductivity

The hydrogen ion conductivity of each of the branched sulfonated multiblock copolymer electrolyte membranes prepared in Examples 4 to 6 was determined by a complex impedance method using two-probe.

First of all, the area of 2x2 (cm2) (cm2) was faced with a carbon paper electrode of 1x1 (cm2) and 1.5x1.5 (cm2) at constant pressure, respectively. In the range of 2 MHz to 10 Hz, an alternating voltage of 5 mA was applied to the polymer membrane to be measured. In this case, Nyquist plots were obtained by using an impedance analyzer (Imp6), and the resistance of each branched sulfonated multi-block copolymer electrolyte membrane was obtained using this. Then, the hydrogen ion conductivity of the electrolyte membrane was calculated according to Equation 2 below.

[Equation 2]

The hydrogen ion conductivity of Example 4 and Nafion 115 was measured and shown in FIG. 1. As shown in FIG. 1, the branched sulfonated multiblock copolymer electrolyte membrane of Example 4 prepared according to the present invention showed a hydrogen ion conductivity comparable to that of Nafion used in the conventional polymer membrane.

C) methanol permeability (MeOH crossover)

The methanol permeability of the branched sulfonated multiblock copolymer electrolyte membrane prepared in Examples 4 to 6 was measured using a diffusion cell apparatus.

First, 10 M aqueous methanol solution was added to one cell, and pure water was added to the other cell. The middle of the cell was separated by the branched sulfonated multiblock copolymer electrolyte membrane prepared in Examples 4 to 6, followed by pure water. The methanol permeability was calculated from the change in methanol concentration (C _i (t)) in the cell over time ( t ) obtained while sampling the solution in the filled cell. In this case, the methanol permeability (D _i K _i ) is expressed from the electrolyte thickness (L) and the exposed area (A) of the membrane, the volume of the right cell (V), and the methanol initial concentration (C _i0 ) of the left cell. Calculated by 3.

[Equation 3]

division Example 4 Example 5 Example 6 Nafion 115 Room temperature 9.73E-7 1.03E-6 1.18E-6 2.40E-6 40 ℃ 1.63E-6 1.78E-6 1.98E-6 3.43E-6 60 ℃ 2.69E-6 2.84E-6 3.15E-6 5.50E-6

Through Table 2, the branched sulfonated multiblock copolymer electrolyte membranes of Examples 4 to 6 prepared according to the present invention had a lower methanol permeability over the entire temperature range compared to the Nafion used in the conventional polymer membranes, thereby further improving. I could confirm it.

The electrolyte membrane according to the present invention can be prepared more simply and effectively multi-block copolymer by block copolymerization of the hydrophobic block and the hydrophilic block directly in one reactor, the electrolyte membrane using the prepared multi-block copolymer is chemical It is stable and has high hydrogen ion conductivity and at the same time excellent mechanical properties, and can control the distribution, position, number, etc. of sulfonic acid groups in the polymer skeleton, and there is almost no deterioration of membrane properties due to the increase of sulfonic acid groups. There is this.

Although only described in detail with respect to the described embodiments of the present invention, it will be apparent to those skilled in the art that various modifications and variations are possible within the technical spirit of the present invention, it is natural that such variations and modifications belong to the appended claims. .

Claims (9)

a) preparing a hydrophilic block by adding a bisphenol monomer or an aromatic dihalogen monomer, a bisphenol monomer having an acid substituent or an aromatic dihalogen monomer having an acid substituent, a carbonate anhydride catalyst and a first organic solvent in a reactor ; And b) in the reactor including the prepared hydrophilic block and the first organic solvent, a bisphenol-based monomer, an aromatic dihalogen-based monomer, a carbonate anhydride catalyst and a second organic solvent are added and polymerized to prepare a hydrophobic block. Preparing a multi-block copolymer; Method for producing a sulfonated multi-block copolymer comprising a. a) preparing a hydrophobic block by adding a bisphenol-based monomer, an aromatic dihalogen-based monomer, a carbonate anhydride catalyst and a first organic solvent in a reactor and polymerizing the same; And b) a bisphenol-based monomer or an aromatic dihalogen-based monomer, a bisphenol-based monomer having an acid substituent or an aromatic dihalogen-based monomer having an acid substituent, or a carbonate in the reactor including the prepared hydrophobic block and the first organic solvent Adding and polymerizing an anhydride catalyst and a second organic solvent to prepare a hydrophilic block and simultaneously preparing a multi-block copolymer; Method for producing a sulfonated multi-block copolymer comprising a. The method according to claim 1 or 2, As the bisphenol-based monomer or aromatic dihalogen-based monomer, 4,4'-difluorobenzophenone, bis (4-fluorophenyl) sulfone, 2,2-bis (4-hydroxyphenyl) hexafluoropropane or Method for producing a sulfonated multiblock copolymer, characterized in that 4,4'-biphenol. The method according to claim 1 or 2, The bisphenol-based monomer having an acid substituent or the aromatic dihalogen-based monomer having an acid substituent is hydroquinone sulfonic acid potassium salt, 2,7-dihydroxynaphthalene-3,6-disulfonic acid disodium salt, 1,7 -Dihydroxynaphthalene-3-sulfonic acid monosodium salt, 2,3-dihydroxynaphthalene-6-sulphonic acid monosodium salt, potassium 5,5'-carnobylbis (2-fluorobenzene sulfonate ), Or potassium 2,2 '-[9,9-bis (4-hydroxyphenyl) fluorene] sulfonate. The method according to claim 1 or 2, In order to manufacture a branched hydrophilic block or a hydrophobic block, a method for producing a multi-block copolymer, characterized in that the addition of a brancher in the hydrophilic block or hydrophobic block manufacturing. The method of claim 5, The brancher is [3,5-bis (4-fluorobenzoyl) phenyl] (4-fluorophenyl) methanone, [3,5-bis (4-fluorosulfonyl) phenyl] (4-fluoro Phenyl) methanone, 3,5-difluoro-4'-fluorobenzophenone and (3,5-difluoro-4'-fluorophenyl) sulfone Method for producing a sulfonated multiblock copolymer. The method according to claim 1 or 2, The carbonate anhydride catalyst is a method for producing a sulfonated multi-block copolymer, characterized in that potassium carbonate. The method according to claim 1 or 2, The first organic solvent or the second organic solvent is selected from the group consisting of N, N'-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide, and N, N-dimethylformamide The manufacturing method of the sulfonated multiblock copolymer made into these. The method according to claim 1 or 2, Method for producing a sulfonated multi-block copolymer electrolyte membrane, characterized in that the weight average molecular weight of the hydrophobic block is 1,000 to 500,000 (g / mol), the weight average molecular weight of the hydrophilic block is 1,000 to 500,000 (g / mol).

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