KR20070054314A - Sulfonated polysulfone ketone copolymer, polymer electrolyte comprising the same, and preparation method thereof - Google Patents

Abstract

The present invention relates to a sulfonated polysulfone ketone copolymer, and a polymer electrolyte including the same, and more particularly, to an aromatic sulfone repeating unit, an aromatic ketone repeating unit, and an aromatic compound repeating unit connecting the repeating unit with an ether bond. And a sulfonated polysulfone ketone copolymer comprising at least one of the aromatic sulfone repeating units and the aromatic ketone repeating units having a sulfonic acid or sulfonate substituent, and a polymer electrolyte comprising the same.

It is excellent in heat resistance and shape stability of the present invention, does not destroy even under low humidity conditions, and excellent hydrogen ion conductivity, which is suitable for use as a polymer electrolyte for fuel cells.

Polysulfone ketone, copolymer, branched, fuel cell, polymer electrolyte

Description

Sulfonated polysulfone ketone copolymer, a polymer electrolyte comprising the same, and a method for preparing the same

[Industrial use]

The present invention relates to a sulfonated polysulfone ketone copolymer, a polymer electrolyte comprising the same, and a method for preparing the same, and more particularly, a copolymer for a polymer electrolyte which is excellent in heat resistance and shape stability, and which is not destroyed even under low humidity conditions. It relates to a polymer electrolyte comprising, and a method for producing the same.

[Private Technology]

The polymer electrolyte fuel cell is a fuel cell using a polymer membrane having hydrogen ion exchange characteristics as an electrolyte, and a solid polymer electrolyte fuel cell (SPEFC) and a hydrogen ion exchange membrane fuel cell (PEMFC). It is called various names.

 Compared to other fuel cells, the polymer electrolyte fuel cell (PEMFC) has a low operating temperature of about 80 ° C, high efficiency, high current density and power density, short start-up time, and fast response to load changes. .

In particular, since the polymer membrane is used as the electrolyte, there is no need for corrosion and electrolyte control, and it is less sensitive to changes in the pressure of the reactor. In addition, since the design is simple, easy to manufacture, and can produce a wide range of outputs, the polymer electrolyte fuel cell (PEMFC) can be applied to a wide variety of fields such as power sources of pollution-free vehicles, on-site power generation, mobile power, and military power. There are advantages to it.

In the fuel cell market, residential fuel cells are expected to be at the forefront. The reason is that it is expected to penetrate the market very quickly when the market penetration begins with technology and economics because it is a new market that has not existed before.

Household fuel cells can be applied to offices and small factories according to the expansion of capacity. The ultimate development direction is to establish a decentralized power system by connecting to the existing transmission and distribution network. Therefore, in developed countries, efforts are being made to develop intelligent meter technology and establish standards that enable two-way meter reading and communication at local utility operators or at home. In other words, the introduction of a new distributed power system is being promoted by combining power energy with information and communication technology.

Fuel cells are expected to replace the market of secondary batteries, and direct methanol fuel cells, which use methanol instead of hydrogen, are drawing attention as fuel cells for portable electronics. The rapid growth of wireless communication devices such as mobile phones, PDAs, and notebook PCs is a new concept that does not require charging, which is a new concept in conventional lithium-based secondary batteries that require charging, and a high power density fuel cell. Cause It is promoting the commercialization of fuel cells. This field requires the development of technologies such as power density and reliability at the cost of low product pressure.

Conventionally, sulfonic acid groups are widely used among functional groups capable of cation exchange because sulfonic acid groups have very high acidity and C-S bonds have strong resistance to oxidation conditions.

If the sulfonic anion is attached to a hydrogen ion as a cation, it has a hydrogen ion exchange effect. In order to maintain the conductivity of the hydrogen ion, water molecules must be present together. In the presence of water molecules, the sulfonic acid groups attached to the membrane dissociate into sulfonic acid anions and hydrogen ions, and the hydrogen ions are moved by concentration gradient or electric field effect, just like hydrogen ions in sulfuric acid solution electrolyte. Hydrogen ion conductivity is greatly influenced by the number of sulfonic acid groups, the membrane structure and the amount of water in the membrane.

The source of water in the hydrogen ion exchange membrane during fuel cell operation may be water generated by inflow from humidified gas or by oxygen polar reaction. This water moves along with hydrogen ions, that is, it shows concentration gradients within the membrane due to electroosmotic attraction, diffusion of product water, and movement by pressure difference between both electrodes. Immersion occurs on the side of the oxygen pole. As the number of water molecules in the membrane decreases, the dissociation of the ion pairs becomes difficult, thus reducing the ionic conductivity. Factors affecting the sorption characteristics of water in the ion exchange membrane include the type and amount of ion exchanger, the type of cation, and the operating temperature.The water phase (liquid or gas phase) and the thermal history of the ion exchange membrane Affects.

The characteristics of the hydrogen ion exchange membrane are mainly expressed in ion exchange capacity (IEC) or equivalent weight (EW), and the properties of the hydrogen ion exchange membrane used as electrolyte for fuel cells are high hydrogen ion conductivity and mechanical properties. Strength, low gas permeability, and mobility of water. Hydrogen ion exchange membranes must be resistant to dehydration because the conductivity of hydrogen ions drops rapidly during dehydration. The membrane must have a high resistance to oxidation and reduction reactions, hydrolysis, etc. which are directly experienced, good cation binding strength, and homogeneity. And these properties must be maintained for some time.

Even if a membrane is developed that satisfies all of these conditions, it is necessary to develop inexpensive and environmentally friendly manufacturing technology to commercialize it. The research on non-fluorine-based polymer materials at this point is mainly based on heat-resistant polymers and introducing polar groups to give them functions as polymer electrolytes.

Sulfonated polyimide (S-PI) membranes, which are polyimide-based polymer electrolytes, are obtained from the condensation reaction of diamines and dianhydrides having sulfonic acid groups. The S-PI membrane has three times lower hydrogen gas permeation than Nafion117 and shows cell performance similar to that of Nafion, but has a lifetime stability of about 3000 hours. This is because the mechanical strength is lowered, such as breaking the chain due to hydrolysis.

Polysulfone is a polymer in which phenyl ring is alternately connected by ether group and sulfone (-SO _2- ) group. Commercially, poly (arylether sulfone), polysulfone (PSU) (trade name Udel) and polyether Polyethersulphone (PES) (trade name Victrex).

S-PSU is less likely to be used for fuel cells because only 30% of sulfonation is dissolved in water. Membranes made of S-PES are very stable in water. However, in order to increase the ionic conductivity, a large amount of sulfonation is essential. As the sulfonation proceeds more, the mechanical strength of the membrane becomes weaker. In the case of S-PES, sulfonation up to 90% is similar to Nafion's conductivity value, in which case swelling up to 400% results in very low mechanical strength. To solve this, the activated sulfonic acid group was properly crosslinked to reduce the swelling by 50%, but the conductivity was also reported to decrease.

Polyetherketone is a polymer linking ether and carbonyl phenyl groups. The most common material is PEEK, also known as Victrex PEEK. When PEEK was directly sulfonated to obtain a membrane, ionic conductivity of 6 × 10 ⁻² S / cm was obtained at room temperature through sulfonation of 60%, and the operation of the PEEK membrane at 50 ° C. showed stability of about 4000 hours.

As a result of crosslinking at 120 ° C. to increase the mechanical strength of polyetherketone, 30% of sulfonic acid groups were changed to sulfone groups and the same mechanical strength as Nafion membrane was obtained (Journal of Membrabe Science 225 2003, 63-76). . From these existing results, an efficient polyelectrolyte membrane should have high hydrogen ion conductivity, good thermal mechanical properties, and low gas methanol permeability to be commercially applicable.

It is an object of the present invention to provide a sulfonated polysulfone ketone copolymer for polymer electrolytes having low gas permeability, high ion conductivity, and excellent structural stability that do not break even under low humidity conditions.

Another object of the present invention is to provide a polymer electrolyte comprising the sulfonated polysulfone ketone copolymer.

Still another object of the present invention is to provide a method for preparing the sulfonated polysulfone ketone copolymer.

In order to achieve the above object, the present invention includes an aromatic sulfone repeating unit, an aromatic ketone repeating unit, and an aromatic compound repeating unit linking the repeating unit with an ether bond, wherein the aromatic sulfone repeating unit and the aromatic ketone repeating unit Sulfonated polysulfone ketone copolymers are provided wherein at least one or more have sulfonic acid or sulfonate substituents.

The present invention also provides a polymer electrolyte for a fuel cell comprising the sulfonated polysulfone ketone copolymer.

The present invention also includes a step of condensing a monomer mixture comprising a sulfonated or unsulfonated aromatic sulfone monomer, a sulfonated or unsulfonated aromatic ketone monomer, and a dihydroxy monomer in the presence of an organic solvent. It provides a method for producing a sulfonated polysulfone ketone copolymer wherein at least one or more of the aromatic sulfone monomer, and aromatic ketone monomer is sulfonated.

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

Among the heat resistant polymers applicable to high temperature polymer electrolytes, polysulfone and polyketone have low manufacturing cost and exhibit considerable stability under oxidation / reduction conditions at various temperature ranges. In addition, due to the electron donor nature of the ether group, sulfonation is easy, and thus shows proper hydrogen ion conductivity.

However, sulfonated polyetheretherketone (S-PEEK) has less hydrophobicity due to the presence of ether groups in the polymer main chain, and thus lower acidity of sulfonyl groups, resulting in less microphase separation between hydrophilic and hydrophobic regions than Nafion. appear.

In the present invention, in order to provide a polymer electrolyte having low gas permeability, high ion conductivity, and high structural stability, a sulfonated polysulfone ketone copolymer was prepared using a crystalline polymer ketone and an amorphous sulfone copolymer.

In addition, a branched sulfonated polysulfone ketone copolymer was prepared using a branching agent containing three or more functional groups to induce more fluid polymer chains.

The sulfonated polysulfone ketone copolymer of the present invention comprises an aromatic sulfone repeating unit, an aromatic ketone repeating unit, and an aromatic compound repeating unit linking the repeating unit with an ether bond, wherein the aromatic sulfone repeating unit, and aromatic ketone repeating unit At least one of them has a sulfonic acid or sulfonate substituent.

In this case, the mole fraction of the repeating unit having the sulfonic acid or sulfonate substituent is preferably 1 to 50 mol%, more preferably 30 to 50, of the aromatic sulfone repeating unit and the aromatic ketone repeating unit. When the number of moles of the repeating unit is 1 mol% or more, sufficient hydrogen ion conduction characteristics may be obtained, and when 50 mol% or less, structural stability may be secured.

In the sulfonated polysulfone ketone copolymer of the present invention, the aromatic sulfone repeating unit is represented by the following Chemical Formula 1, and the aromatic ketone repeating unit is represented by the following Chemical Formula 2, and the aromatic compound repeats connecting the repeating unit by an ether bond. The unit is represented by the following formula (3), the aromatic sulfone repeating unit having a sulfonic acid or sulfonate substituent is represented by the following formula (4), the aromatic ketone repeating unit having a sulfonic acid or sulfonate substituent is preferably represented by the following formula (5).

[Formula 1]

[Formula 2]

[Formula 3]

[Formula 4]

[Formula 5]

Where

M ¹ , M ² , M ³ , and M ⁴ are each independently one or more selected from the group consisting of hydrogen, sodium, lithium, and potassium,

로 이루어진 군에서 선택되는 1종 이상의 케톤이고, K is -CO-, -CO-CO-, and

At least one ketone selected from the group consisting of

X is 1 type selected from the group consisting of -O-, -S-, -NH-, -SO _2- , -CO-, -C (CH ₃ ) _2- , and -C (CF ₃ ) _2- That's it,

R ¹ , R ² , R ³ , R ⁴ , and R ⁵ are each independently an aromatic ring having 5 to 30 carbon atoms and at least 1 to 30 carbon atoms containing at least one hetero atom selected from the group consisting of oxygen, nitrogen, and sulfur; At least one member selected from the group consisting of an alkyl substituent of 30,

a, b, and c are each independently an integer of 0 to 4,

x and x 'are each independently an integer of 0-3, y and y' are each independently an integer of 1-4, x + y and x '+ y' are each independently an integer of 1-4.

The above definitions for substituents apply equally to all formulas mentioned below.

The polysulfone ketone copolymer of the present invention more preferably includes a molecular structure represented by the following formula (6) or (7) in terms of ion conductivity and structural stability.

[Formula 6]

[Formula 7]

The sulfonated polysulfone ketone copolymer of the present invention preferably has a weight average molecular weight of 10,000 to 200,000 in terms of mechanical strength and hydrogen ion conductivity, and more preferably 30,000 to 150,000.

The sulfonated polysulfone ketone copolymer of the present invention may be a linear polymer or a branched polymer, and may be a branched polymer further comprising a branching unit derived from a compound represented by the following Chemical Formulas 8 to 15: More preferred.

[Formula 8]

[Formula 9]

[Formula 10]

[Formula 11]

[Formula 12]

[Formula 13]

[Formula 14]

[Formula 15]

In order for the branched sulfonated polysulfone ketone copolymer of the present invention to have more excellent mechanical properties, the branched units may include 0.1 mol% or more based on the total amount of the repeating units of the aromatic compound connecting the remaining repeating units with ether bonds. It is preferable to be included in 1 mol% or less in order to prevent the fall of the workability by excessive crosslinking.

The branched sulfonated polysulfone ketone copolymer of the present invention is more preferably a sulfonated polysulfone ketone copolymer which is a branched polymer including a molecular structure represented by the following formula (16) or (17).

[Formula 16]

[Formula 17]

The sulfonated polysulfone ketone copolymer of the present invention can be used as a polymer electrolyte having hydrogen ion conductivity, and in particular in the form of a polymer electrolyte membrane for a fuel cell.

It can be seen that the polymer electrolyte containing sulfonated polysulfone ketone according to the present invention exhibits very high hydrogen ion conductivity and significantly lower methanol permeability.

In particular, branched sulfonated polysulfone ketone copolymers have narrow main chain and chain-like spacing and narrow passageways that prevent relatively large molecules from permeating. Therefore, the branched sulfone ketone polymer prepared by the present invention is excellent in film formation of thin film production and shows stability against redox.

More specifically, the polymer electrolyte containing the sulfonated polysulfone ketone copolymer of the present invention preferably has a hydrogen ion conductivity of 1.5 × 10 ^-4 S / cm or more, and 1.5 × 10 ^-4 to 1 × 10 ^-1 S /. It is preferable that it is cm, and it is preferable that methanol transmittance is 1.0 * 10 <^-6> cm <^2> / sec or less, and it is more preferable that it is 1 * 10 <^-9> -1 * 10 <^-6> cm <^2> / sec. When the range of the hydrogen ion conductivity and the methanol transmittance is satisfied, a sufficient effect can be obtained as a direct methanol fuel cell (DMFC) polymer electrolyte.

The sulfonated polysulfone ketone copolymers of the present invention condense a monomer mixture comprising a sulfonated or unsulfonated aromatic sulfone monomer, a sulfonated or unsulfonated aromatic ketone monomer, and a dihydroxy monomer in the presence of an organic solvent. It can be produced by a method of reacting, wherein at least one of the aromatic sulfone monomer and the aromatic ketone monomer is preferably sulfonated.

Specific examples of the monomer mixture

a) a monomer mixture comprising an aromatic sulfone monomer, a sulfonated aromatic ketone monomer, and an aromatic dihydroxy monomer;

b) monomer mixtures comprising aromatic ketone monomers, sulfonated aromatic sulfone monomers, and aromatic dihydroxy monomers;

c) monomer mixtures comprising sulfonated aromatic ketone monomers, sulfonated aromatic sulfone monomers, and aromatic dihydroxy monomers;

d) monomer mixtures comprising aromatic sulfone monomers, aromatic ketone monomers, sulfonated aromatic ketone monomers, and aromatic dihydroxy monomers;

e) monomer mixtures comprising aromatic sulfone monomers, aromatic ketone monomers, sulfonated aromatic sulfone monomers, and aromatic dihydroxy monomers; or

f) monomer mixtures comprising aromatic sulfone monomers, aromatic ketone monomers, sulfonated aromatic ketone monomers, sulfonated aromatic sulfone monomers, and aromatic dihydroxy monomers.

In the monomer mixture, the aromatic sulfone monomer is represented by the following Chemical Formula 18, the aromatic ketone monomer is represented by the following Chemical Formula 19, the aromatic dihydroxy monomer is represented by the following Chemical Formula 20, and the sulfonated aromatic sulfone monomer is It is represented by the formula (21), it is preferable that the sulfonated aromatic ketone monomer is represented by the following formula (22).

[Formula 18]

[Formula 19]

[Formula 20]

[Formula 21]

[Formula 22]

Where

M ¹ , M ² , M ³ , and M ⁴ are each independently one or more selected from the group consisting of hydrogen, sodium, lithium, and potassium,

로 이루어진 군에서 선택되는 1종 이상의 케톤이고, K is -CO-, -CO-CO-, and

At least one ketone selected from the group consisting of

X is one or more selected from the group consisting of -O-, -S-, -NH-, -SO _2- , -CO-, -C (CH ₃ ) _2- , and -C (CF ₃ ) _2- ego,

Each Y is independently at least one halogen group element selected from the group consisting of fluorine, chlorine, bromine, and iodine,

R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , and R ⁷ each independently have 5 to 5 carbon atoms containing one or more heteroatoms selected from the group consisting of oxygen, nitrogen, and sulfur. At least one member selected from the group consisting of an aromatic ring having 30 and an alkyl substituent having 1 to 30 carbon atoms,

a, b, and c are each independently an integer of 0 to 4,

x and x 'are independently an integer of 0-3, y and y' are independently an integer of 1-4, x + y and x '+ y' are independently an integer of 1-4.

The conditions of the condensation reaction of the monomer mixture are the same as those of the conventional etherification reaction, and are not particularly limited in the present invention, and thus detailed description thereof is omitted.

In addition, the branched sulfonated polysulfone ketone copolymer of the present invention may further include at least one polyfunctional monomer selected from the group consisting of the compounds represented by Formulas 8 to 15 to the monomer mixture of a) to f). It can be prepared by polymerization. The amount of the polyfunctional monomer added is based on the content of the branching units described above.

Hereinafter, preferred embodiments of the present invention are described. However, the following examples are only preferred embodiments of the present invention, and the present invention is not limited to the following examples.

EXAMPLE

Preparation Example 1

(Preparation of sulfonated aromatic ketone monomer)

30 g of 4,4'-difluorobenzopenone was added to a 250 mL flask, and 70 mL of fuming sulfuric acid (30%) was slowly added to the flask to completely dissolve the difluorobenzophenone. Then, the temperature was gradually heated and reacted at 110 ° C. for about 7 hours.

The reaction solution was cooled to room temperature, poured into iced water, cooled completely, and neutralized by adding an excess of NaOH to the mixture, followed by addition of 1 M NaCl solution to 3,3'-disodiumsulfonyl-4,4'- Difluorophenylketone solid was obtained.

The solid was filtered off and dried to recrystallize. Recrystallization was carried out in 2 times using isopropyl alcohol and water. The total yield of the sulfonated 4,4'-difluorobenzophenone was about 75%, and the compound was identified using ¹ H-NMR and FT-IR (KBr).

¹ H NMR (300 MHz) δ 7.3 (H, ortho H of fluorophenyl), δ 7.7 (H, meta H of fluorophenyl), δ 8.0 (H, ortho H of ketone).

FT-IR (KBr) 1664 cm ^-1 (C = O), 1259 cm ^-1 and 1093 cm ^-1 (S = O), 624 cm ^-1 (C = S).

Preparation Example 2

(Preparation of sulfonated aromatic sulfone monomer)

30 g of bis (4-fluorophenyl) sulfone was added to a 250 mL flask, and 70 mL of fuming sulfuric acid (30%) was slowly added to the flask to completely dissolve the bis (4-fluorophenyl) sulfone, and then gradually heated to a temperature. The reaction was performed at 110 ° C. for about 7 hours.

The reaction solution was cooled to room temperature, poured into iced water, cooled completely, and neutralized by adding an excess of NaOH to the mixture, followed by addition of 1M NaCl solution to 3,3'-disodiumsulfonyl-4-4'-difluor A rophenylsulfone solid was obtained.

The solid was filtered and dried to recrystallize. Recrystallization was carried out over two times using methanol and water. The yield of the 3,3'-disodiumsulfonyl-4-4'-difluorophenylsulfone was about 75%, and the compound was confirmed by ¹ H-NMR and FT-IR (KBr).

¹ H NMR (300 MHz) δ 7.43 (H, ortho H of fluorophenyl), δ 7.95 (H, meta H of fluorophenyl), δ 8.17 (H, ortho H of sulfone).

FT-IR (KBr) 1093 cm ⁻¹ (S = O), 624 cm ⁻¹ (C = S).

Example 1

(Synthesis of sulfonated polysulfone ketone copolymer)

A 100 mL three-necked flask was equipped with a Dean-stark trap and condenser, 0.01 mol of bisphenol A, 0.005 mol of 4,4'-difluorobenzophenone, 3,3'-disodiumsulfonyl-4,4'-di After dissolving 0.005 mol of 3,3'-disodiumsufonyl-4,4'-difluoropenylsulfone in 15 mL of N-methylpyrrolidone (NMP), tris-4-hydroxyphenylethane (tris-4- hydroxyphenylethane) 0.00002 mol (0.2 mol% of bisphenol A) was added.

K ₂ CO ₃ (0.026 mol) was added thereto, the temperature was raised to 70 ° C., 10 mL of toluene was added thereto, and the reaction product was refluxed for 5 hours to remove water.

After removing water, increase the temperature to 160 ℃ Toluene was removed, and the reaction was performed at 160 ° C. for about 6 hours after toluene removal to prepare a sulfonated polysulfone ketone copolymer.

The sulfonated polysulfone ketone copolymer prepared above was precipitated in 200 mL of a mixed solution of water and methanol (volume ratio 3: 7) to obtain a solid. The viscosity of the obtained solid was about 0.3 to 0.5 g / dL.

(Production of Polymer Electrolyte Membrane)

The polymer obtained above was dissolved in NMP, cast using a flat glass plate and a round glass tube, and then dried in a vacuum oven at 70 ° C. to prepare a brown transparent membrane having a thickness of 20 to 50 μm.

The membrane was immersed in 0.1 N hydrochloric acid solution for 5 hours and then dried to measure membrane properties.

Example 2

0.01 mol of bisphenol A, 0.006 mol of 4,4'-difluorobenzophenone, 0.004 mol of 3,3'-disodiumsulfonyl-4,4'-difluorophenylsulfone, and tris-4-hydroxyphenylethane A sulfonated polysulfone ketone and a polymer electrolyte membrane were prepared in the same manner as in Example 1 except that 0.00002 mol (0.2 mol% of bisphenol A) was used.

Example 3

Bisphenol A 0.01 mol, 4,4'-difluorobenzophenone 0.007 mol, 3,3'-disodiumsulfonyl-4,4'-difluorophenylsulfone 0.003 mol, tris-4-hydroxyphenylethane 0.00002 A sulfonated polysulfone ketone and a polymer electrolyte membrane were prepared in the same manner as in Example 1 except that mol (0.2 mol% of bisphenol A) was used.

Example 4

Bisphenol A 0.01 mol, 4,4'-difluorobenzophenone 0.008 mol, 3,3'-disodiumsulfonyl-4,4'-difluorophenylsulfone 0.002 mol, tris-4-hydroxyphenylethane 0.00002 A sulfonated polysulfone ketone and a polymer electrolyte membrane were prepared in the same manner as in Example 1 except that mol (0.2 mol% of bisphenol A) was used.

Example 5

Bisphenol A 0.01 mol, 4,4'-difluorobenzophenone 0.009 mol, 3,3'-disodiumsulfonyl-4,4'-difluorophenylsulfone 0.001 mol, tris-4-hydroxyphenylethane 0.00002 A sulfonated polysulfone ketone and a polymer electrolyte membrane were prepared in the same manner as in Example 1 except that mol (0.2 mol% of bisphenol A) was used.

Example 6

Bisphenol A 0.01 mol, 4,4'-difluorophenylsulfone 0.005 mol, 3,3'-disosulfonyl-4,4'-difluorophenylketone 0.005 mol, tris-4-hydroxyphenylethane 0.00002 A sulfonated polysulfone ketone and a polymer electrolyte membrane were prepared in the same manner as in Example 1 except that mol (0.2 mol% of bisphenol A) was used.

Example 7

Bisphenol A 0.01 mol, 4,4'-difluorophenylsulfone 0.006 mol, 3,3'-disodiumsulfonyl-4,4'-difluorophenylketone 0.004 mol, tris-4-hydroxyphenylethane 0.00002 A sulfonated polysulfone ketone and a polymer electrolyte membrane were prepared in the same manner as in Example 1 except that mol (0.2 mol% of bisphenol A) was used.

Example 8

Bisphenol A 0.01 mol, 4,4'-difluorophenylsulfone 0.007 mol, 3,3'-disodiumsulfonyl-4,4'-difluorophenylketone 0.003 mol, tris-4-hydroxyphenylethane 0.00002 A sulfonated polysulfone ketone and a polymer electrolyte membrane were prepared in the same manner as in Example 1 except that mol (0.2 mol% of bisphenol A) was used.

Example 9

Bisphenol A 0.01 mol, 4,4'-difluorophenylsulfone 0.008 mol, 3,3'-disodiumsulfonyl-4,4'-difluorophenylketone 0.002 mol, tris-4-hydroxyphenylethane 0.00002 A sulfonated polysulfone ketone and a polymer electrolyte membrane were prepared in the same manner as in Example 1 except that mol (0.2 mol% of bisphenol A) was used.

Example 10

Bisphenol A 0.01 mol, 4,4'-difluorophenylsulfone 0.009 mol, 3,3'-disodiumsulfonyl-4,4'-difluorophenylketone 0.001 mol, tris-4-hydroxyphenylethane 0.00002 A sulfonated polysulfone ketone and a polymer electrolyte membrane were prepared in the same manner as in Example 1 except that mol (0.2 mol% of bisphenol A) was used.

Examples 11-20

Sulfonated polysulfone ketones and polymer electrolyte membranes were prepared in the same manner as in Examples 1 to 10, except that tris-4-hydroxyphenylethane was not used.

Example 21

Bisphenol A 0.01 mol, 4,4'-difluorophenylsulfone 0.005 mol, 3,3'-disodiumsulfonyl-4,4'-difluorophenylketone 0.005 mol, tris-4-hydroxyphenylethane 0.00003 A sulfonated polysulfone ketone and a polymer electrolyte membrane were prepared in the same manner as in Example 1 except that mol (0.1 mol% of bisphenol A) was used.

Comparative Example 1

Commercially available Nafion 115 was used as the polymer electrolyte membrane.

Comparative Example 2

Commercially available Nafion 112 was used as the polymer electrolyte membrane.

Comparative Example 3

A polymer electrolyte membrane was prepared in the same manner as in Example 1 using 80% sulfonated polyether ether ketone (S-PEEK) obtained by sulfonation of Victrex polyether ether ketone (PEEK) with concentrated sulfuric acid.

The hydrogen ion conductivity of the polymer electrolyte membrane obtained according to Examples 1 to 20 and Comparative Examples 1 to 3 was measured. Hydrogen ion conductivity was measured by placing a polymer film between electrodes of an area of 2.54 cm ² and measuring the initial resistance at 30 ° C. using an impedance analyzer. The measurement formula is the same as formula 1 below and the measured values are shown in Table 1 below.

[Calculation 1]

Hydrogen ion conductivity (S / cm) = (film thickness (cm) / area (cm ² )) × initial conductivity (S)

In order to measure the degree of methanol permeation, the prepared polymer electrolyte membrane was placed in the middle of two cells and fixed using an epoxy adhesive. Put 15 mL of 1 mol of aqueous methanol solution into one cell, add 15 mL of distilled water into the other cell, divide 10 μl once every 10 minutes from the cell containing distilled water, and add 10 μl of distilled water to 10 mL. Fit. The methanol concentration of the aliquoted samples was measured using gas chromatography.

A graph of methanol change over time was prepared and the permeability was calculated by the slope 2 as a slope, and the results are shown in Table 1 below.

[Calculation 2]

The fixed value in the above formula is 3 cm in diameter of membrane, 1 mol of methanol concentration (32000 ppm) and 15 mL of solution volume.

TABLE 1

Example Hydrogen ion conductivity (S / cm) Methanol Permeability (cm ² / s) Example Hydrogen ion conductivity (S / cm) Methanol Permeability (cm ² / s) One 8.9 × 10 ^-4 4.7 × 10 ^-7 11 3.1 × 10 ^-4 5.5 × 10 ^-7 2 1.0 × 10 ^-3 4.6 × 10 ^-7 12 7.8 × 10 ^-4 6.6 × 10 ^-7 3 2.5 × 10 ^-3 4.2 × 10 ^-7 13 9.8 × 10 ^-4 4.3 × 10 ^-7 4 5.9 × 10 ^-3 3.8 × 10 ^-7 14 1.5 × 10 ^-3 2.2 × 10 ^-7 5 5.6 × 10 ^-3 3.6 × 10 ^-7 15 5.2 × 10 ^-3 4.6 × 10 ^-7 6 1.5 × 10 ^-4 2.1 × 10 ^-7 16 9.5 × 10 ^-5 1.2 × 10 ^-7 7 2.2 × 10 ^-4 4.6 × 10 ^-7 17 1.8 × 10 ^-4 2.4 × 10 ^-7 8 3.0 × 10 ^-4 5.9 × 10 ^-7 18 2.5 × 10 ^-4 2.1 × 10 ^-7 9 3.1 × 10 ^-3 3.2 × 10 ^-7 19 5.5 × 10 ^-4 3.2 × 10 ^-7 10 3.5 × 10 ^-4 2.2 × 10 ^-7 20 4.3 × 10 ^-4 5.7 × 10 ^-7 21 4.5 × 10 ^-4 3.7 × 10 ^-7 Comparative Example 1 1.2 × 10 ^-2 2.2 × 10 ^-6 Comparative Example 2 1.0 × 10 ^-2 1.7 × 10 ^-6 Comparative Example 3 1.4 × 10 ^-2 2.0 × 10 ^-6

As shown in Table 1, the polymer electrolyte membrane prepared according to Examples 1 to 21 of the present invention has excellent hydrogen ion conductivity and low methanol permeability.

In particular, the Nafion polymer electrolyte membranes of Comparative Examples 1 and 2 have excellent hydrogen ion conductivity, but in methanol permeability, they are about 10 times higher than the polymer electrolyte membrane according to the embodiment of the present invention. The PEEK polymer electrolyte membrane lacked chemical stability in water and methanol solution and was dissolved in water and methanol mixed solvent.

 It is excellent in heat resistance and shape stability of the present invention, does not destroy even under low humidity conditions, and excellent hydrogen ion conductivity, which is suitable for use as a polymer electrolyte for fuel cells.

Claims (12)

An aromatic sulfone repeating unit, an aromatic ketone repeating unit, and an aromatic compound repeating unit connecting the repeating unit with an ether bond, A sulfonated polysulfone ketone copolymer, wherein at least one or more of the aromatic sulfone repeating units and aromatic ketone repeating units have a sulfonic acid or sulfonate substituent. The method of claim 1, A sulfonated polysulfone ketone copolymer, wherein the aromatic sulfone repeating unit and the repeating unit having a sulfonic acid or sulfonate substituent in the aromatic ketone repeating unit are 1 to 50 mol%. The method of claim 1, The aromatic sulfone repeating unit is represented by the following formula (1), The aromatic ketone repeating unit is represented by the following formula (2), An aromatic compound repeating unit connecting the repeating unit by an ether bond is represented by the following formula (3), An aromatic sulfone repeating unit having a sulfonic acid or sulfonate substituent is represented by the following formula (4), An aromatic ketone repeating unit having a sulfonic acid or sulfonate substituent is represented by the following formula (5) Phosphorus sulfonated polysulfone ketone copolymers: [Formula 1]

[Formula 2]

[Formula 3]

[Formula 4]

[Formula 5]

Where M ¹ , M ² , M ³ , and M ⁴ are each independently one or more selected from the group consisting of hydrogen, sodium, lithium, and potassium, K is -CO-, -CO-CO-, and

At least one ketone selected from the group consisting of X is one or more selected from the group consisting of -O-, -S-, -NH-, -SO _2- , -CO-, -C (CH ₃ ) _2- , and -C (CF ₃ ) _2- ego, R ¹ , R ² , R ³ , R ⁴ , and R ⁵ are each independently an aromatic ring having 5 to 30 carbon atoms and at least 1 to 30 carbon atoms containing at least one hetero atom selected from the group consisting of oxygen, nitrogen, and sulfur; At least one member selected from the group consisting of an alkyl substituent of 30, a, b, and c are each independently an integer of 0 to 4, x and x 'are each independently an integer of 0-3, y and y' are each independently an integer of 1-4, x + y and x '+ y' are each independently an integer of 1-4. The method of claim 1, The polysulfone ketone copolymer is a sulfonated polysulfone ketone copolymer comprising a molecular structure represented by the following formula (6) or (7): [Formula 6]

[Formula 7]

Where R ¹ , R ² , R ³ , and R ⁴ are each independently an aromatic ring having 5 to 30 carbon atoms and alkyl having 1 to 30 carbon atoms containing at least one hetero atom selected from the group consisting of oxygen, nitrogen, and sulfur At least one selected from the group consisting of substituents, M ¹ , M ² , M ³ , and M ⁴ are each independently one or more selected from the group consisting of hydrogen, sodium, lithium, and potassium, a and b are each independently an integer of 0 to 4, x and x 'are each independently an integer of 0-3. The method of claim 1, The polysulfone ketone copolymer is a sulfonated polysulfone ketone copolymer having a weight average molecular weight of 10,000 to 200,000. The method of claim 1, The polysulfone ketone copolymer is a sulfonated polysulfone ketone, which is a branched polymer further comprising a branching unit derived from one or more polyfunctional monomers selected from the group consisting of compounds represented by the following Formulas 8 to 15: Copolymer: [Formula 8]

[Formula 9]

[Formula 10]

[Formula 11]

[Formula 12]

[Formula 13]

[Formula 14]

[Formula 15]

. The method of claim 6, The branching unit is a sulfonated polysulfone ketone copolymer of 0.1 to 1 mol% based on the aromatic compound repeating unit connecting the aromatic ketone and the aromatic sulfone repeating unit by an ether bond. The method of claim 6, The polysulfone ketone copolymer is a sulfonated polysulfone ketone copolymer which is a branched polymer including a molecular structure represented by the following Chemical Formula 16 or 17: [Formula 16]

[Formula 17]

Where R ¹ , R ² , R ³ , and R ⁴ are each independently an aromatic ring having 5 to 30 carbon atoms and alkyl having 1 to 30 carbon atoms containing at least one hetero atom selected from the group consisting of oxygen, nitrogen, and sulfur At least one selected from the group consisting of substituents, M ¹ , M ² , M ³ , and M ⁴ are each independently one or more selected from the group consisting of hydrogen, sodium, lithium, and potassium, a and b are each independently an integer of 0 to 4, x and x 'are each independently an integer of 0-3. A fuel cell polymer electrolyte comprising the sulfonated polysulfone ketone copolymer according to any one of claims 1 to 8. 10. The fuel cell polymer electrolyte of claim 9, wherein the polymer electrolyte has a membrane shape. a) a monomer mixture comprising an aromatic sulfone monomer, a sulfonated aromatic ketone monomer, and an aromatic dihydroxy monomer; b) monomer mixtures comprising aromatic ketone monomers, sulfonated aromatic sulfone monomers, and aromatic dihydroxy monomers; c) monomer mixtures comprising sulfonated aromatic ketone monomers, sulfonated aromatic sulfone monomers, and aromatic dihydroxy monomers; d) monomer mixtures comprising aromatic sulfone monomers, aromatic ketone monomers, sulfonated aromatic ketone monomers, and aromatic dihydroxy monomers; e) monomer mixtures comprising aromatic sulfone monomers, aromatic ketone monomers, sulfonated aromatic sulfone monomers, and aromatic dihydroxy monomers; or f) monomer mixtures comprising aromatic sulfone monomers, aromatic ketone monomers, sulfonated aromatic ketone monomers, sulfonated aromatic sulfone monomers, and aromatic dihydroxy monomers Condensation reaction in the presence of an organic solvent, The aromatic sulfone monomer is represented by the following formula (18), The aromatic ketone monomer is represented by the following formula (19), The aromatic dihydroxy monomer is represented by the formula (20), The sulfonated aromatic sulfone monomer is represented by the following formula 21, The sulfonated aromatic ketone monomer is represented by the following formula (22) Process for preparing phosphorus sulfonated polysulfone ketone copolymer: [Formula 18]

[Formula 19]

[Formula 20]

[Formula 22]

[Formula 19]

Where M ¹ , M ² , M ³ , and M ⁴ are each independently one or more selected from the group consisting of hydrogen, sodium, lithium, and potassium, K is -CO-, -CO-CO-, and

At least one ketone selected from the group consisting of X is at least one member selected from the group consisting of-, -S-, -NH-, -SO _2- , -CO-, -C (CH ₃ ) _2- , and -C (CF ₃ ) _2- , Each Y is independently at least one halogen group element selected from the group consisting of fluorine, chlorine, bromine, and iodine, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , and R ⁷ are aromatic rings having 5 to 30 carbon atoms containing at least one hetero atom selected from the group consisting of oxygen, nitrogen, and sulfur; At least one selected from the group consisting of alkyl substituents having 1 to 30 carbon atoms, a, b, and c are each independently an integer of 0 to 4, x and x 'are each independently an integer of 0-3, y and y' are each independently an integer of 1-4, x + y and x '+ y' are each independently an integer of 1-4. The method of claim 11, The method of preparing a sulfonated polysulfone ketone copolymer, wherein the monomer mixture of a) to f) further comprises at least one polyfunctional monomer selected from the group consisting of compounds represented by the following Formulas 8 to 15: [Formula 8]

[Formula 9]

[Formula 10]

[Formula 11]

[Formula 12]

[Formula 13]

[Formula 14]

[Formula 15]

.