KR20080022675A - Organic-inorganic composite polymer and polymer electrolyte membrane using the same - Google Patents

Abstract

An organic-inorganic composite polymer, and a polymer electrolyte membrane for a fuel cell containing the polymer are provided to improve hydrogen ion conductivity, moldability and structural stability and to reduce the crossover of a reaction fuel or an oxidizing agent. An organic-inorganic composite polymer comprises 100 parts by weight of a sulfonated polysulfoneketone copolymer; and 0.1-14 parts by weight of an inorganic particle. Preferably the inorganic particle is selected from the group consisting of silicon oxide, phosphatoantimonic acid, phosphoric acid, cesium and phosphotungstic acid and has a particle size of 1 nm to 10 micrometers; and the sulfonated polysulfoneketone copolymer comprises an aromatic sulfone repeating unit, an aromatic ketone repeating unit and an aromatic repeating unit connecting the repeating units by ether bond.

Description

ORGANIC-INORGANIC COMPOSITE POLYMER AND POLYMER ELECTROLYTE MEMBRANE USING THE SAME}

FIG. 1 is a graph showing methanol permeability results when Nafion 115 is used as a polymer electrolyte membrane.

FIG. 2 is a graph showing the results of hydrogen ion conductivity when Nafion 115 is used as a polymer electrolyte membrane.

The present invention relates to an organic-inorganic composite polymer and a polymer electrolyte membrane using the same. More particularly, by adding nano-sized to micrometer-sized inorganic particles to a polymer electrolyte including a sulfonic acid group, methanol permeability is greatly reduced to reduce the fuel cell. The present invention relates to an organic-inorganic composite polymer having reduced methanol crossover, high ion conductivity, and excellent structural stability, which is not damaged even under low humidity conditions, and a polymer electrolyte membrane for a fuel cell using the same.

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), a hydrogen ion exchange membrane fuel cell (PEMFC, Proton Exchange Membrane Fuel Cells) It is called various names.

The polymer electrolyte fuel cell (PEMFC) has a low operating temperature of about 80 ° C., high efficiency, high current density and high output density, short start-up time, and quick response to load changes, compared to other types of fuel cells. have.

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 a power source of a pollution-free vehicle, on-site power generation, mobile power, and military power. There are advantages to it.

Fuel cells are developing faster as time goes by, leading to faster market prospects. Fuel cells have already undergone much technical verification, and economic verification is in progress. In other words, price reduction and infrastructure are being built by mass production. In addition, due to environmental regulations, strong support from the government's development costs and tax benefits, and the efforts of large companies in the existing energy and automotive industries, the market development will proceed, and the perception of the new energy industry is expected to change. One thing is certain: fuel cells are driving the 21C new energy stream. Accordingly, the fuel cell market is expected to be at the forefront of residential fuel cells (Residential Power Generator). 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.

On the other hand, fuel cells have the advantage of not needing to install transmission and distribution network as a concept of remote power source in the US, but in reality, it will be easy to penetrate the market in countries with well-equipped city gas infrastructure such as Korea, Japan, and Taiwan. . In this case, since the city gas, which is natural gas, must be used as a fuel, many development efforts have been made in the fuel reformer field in Japan and the like.

On the other hand, home fuel cells can be applied to offices, small factories, etc. as the capacity expands, and the ultimate development direction is to establish a distributed power system by connecting to an existing transmission and distribution network. Therefore, in developed countries, efforts are being made to develop intelligent meter technology and establish standards for bidirectional 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.

One of the biggest markets for fuel cells is the automotive market. Despite many efforts by governments and industries, the direction of economics and infrastructure has not been clearly established yet. Fuel cells are most heavily under cost pressure for commercialization among applications. In 2003, when pollution-free cars are forcibly introduced under the Clean Air Act of the United States, commercialization begins. The introduction of fuel cell vehicles is expected to increase gradually. Replacing an existing internal combustion engine vehicle may take 100 years. For example, in 2000, the number of domestic automobiles is about 12 million, and 100 years are required even if 120,000 units are replaced a year. Therefore, fuel cell vehicles and existing internal combustion engine vehicles will coexist for a long time together, and economic feasibility including fuel and infrastructure problems will be a major issue.

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 can replace the existing lithium-based secondary batteries that require charging. It is accelerating the commercialization of fuel cells, a new power source that has been greatly increased. However, this field requires the development of technologies such as output density and reliability at the cost of low product pressure.

Conventionally, sulfonic acid groups are used commercially as hydrogen ion exchange membrane materials among functional groups having cation exchange capability because sulfonic acid groups have a very high acidity and CS bonds exhibit strong resistance to oxidation conditions. . When hydrogen ions are attached to the sulfonic anion as a cation, they form a hydrogen ion exchange membrane. Water molecules must be present together to maintain high conductivity of the protons. 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 protons 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 the hydrogen ions (i.e., electroosmotic attraction, diffusion of product water, and movement due to pressure difference between both electrodes), resulting in concentration gradients within the membrane. In the oxygen electrode side, immersion occurs. As the number of water molecules in the membrane decreases, the dissociation of the ion pairs becomes difficult and the ionic conductivity decreases. Important 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 strength, and low gas permeability and water mobility. In addition, when the hydrogen ion exchange membrane is dehydrated, since the hydrogen ion conductivity drops sharply, it must be resistant to 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 in order to link it with commercialization. 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 (hereinafter referred to as S-PI) membrane, which is a polyimide-based polyelectrolyte used in the related art, is obtained from a condensation reaction of a diamine having a sulfonic acid group and a dianhydride. The obtained S-PI film showed a cell performance similar to that of Nafion with three times lower hydrogen gas permeation than Nafion 117, but exhibited a lifespan stability of about 3000 hours. This is because the chain is broken by the hydrolysis and the mechanical strength is lowered.

In addition, polysulfone polyelectrolyte is a polymer in which a phenyl ring is alternately connected by an ether group and a sulfone (-SO _2- ) group, and commercially poly (arylether sulfone), polysulfone, PSU (trade name Udel) and polyether sulfone (PES; trade name Victrex). The S-PSU is less likely to be used for fuel cells because it is soluble in water even with 30% sulfonation. Membranes made of S-PES are very stable in water. However, in order to have a desired ion conductivity, a large amount of sulfonation is essential, but as the sulfonation proceeds more, 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 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 이온 10 ^-2 S / cm was obtained at room temperature through 60% sulfonation, and the operation of the PEEK membrane at 50 ° C showed about 4000 hours of stability.

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). (S-PEEK).

On the other hand, there is a conventional technique for adding an inorganic material is a modified Nafion polymer electrolyte membrane, there is a method of manufacturing a Nafion / silicon composite membrane by a sol-gel process using Nafion 115 and tetraethoxysilane (TEOS) [ D. H. Jung, S. Y. Cho, D. H. Peck, D. R. Shin and J. S. Kim, Journal of Power Sources, 173-177 106 (2002)]. In this case, methanol permeability decreased as the content of silicon oxide increased, and the cell using the membrane showed a current density of 650 mA / cm 2 at 120 ° C. and 0.5V, and the hydrogen ion conductivity was 0.080 S / cm (Nafion 115). : 0.073 S / cm) reported higher performance than commercial membranes.

From these existing results, an efficient polyelectrolyte membrane must have high hydrogen ion conductivity, have excellent thermal mechanical properties, and exhibit low gas methanol permeability for commercial application.

An object of the present invention is an organic-inorganic composite for polymer electrolyte which can improve the performance of a fuel cell due to low gas permeability, high ionic conductivity, excellent structural stability, no damage even under low humidity conditions, and low crossover of reaction fuel or oxidant. It is to provide a polymer.

Another object of the present invention is to provide a polymer electrolyte membrane comprising the organic-inorganic composite polymer.

In order to achieve the above object, the present invention provides an organic-inorganic composite polymer comprising inorganic particles in an amount of 0.1 to 14 parts by weight with respect to 100 parts by weight of sulfonated polysulfone ketone copolymer.

Another object of the present invention is to provide a polymer electrolyte membrane for a fuel cell including the organic-inorganic composite polymer.

Hereinafter, the present invention will be described in 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, the conventional sulfonated polyether ether ketone (S-PEEK) has a weakness between hydrophilic and hydrophobic regions compared to Nafion due to the hydrophobicity due to the presence of ether groups in the polymer main chain and the decrease in acidity of sulfonyl groups. Less segregation of the world is seen.

Accordingly, the present invention is to prepare a sulfonated polysulfone ketone copolymer using a crystalline polymer ketone and an amorphous sulfone copolymer in order to provide a polymer electrolyte having low gas permeability, high ion conductivity and high structural stability, Adding nanoparticles of several nanometers or micrometers in size increases the mechanical strength and greatly reduces the permeability of methanol, thereby improving the performance of the battery.

In addition, the present invention may optionally use a branched sulfonated polysulfone ketone copolymer when preparing the organic-inorganic composite polymer. The branched sulfonated polysulfone ketone copolymer is prepared by further using a branching agent including three or more functional groups to induce more fluid polymer chains.

The organic-inorganic composite polymer electrolyte including the sulfonated polysulfone ketone copolymer and the inorganic particles according to the present invention exhibits very high hydrogen ion conductivity, and the methanol permeability is also significantly lowered. In particular, in the preparation of the organic-inorganic composite polymer, when using a branched sulfonated polysulfone ketone copolymer, the main chain and the chain-like spacing is narrowed and the passage is narrowed so that relatively large molecules do not penetrate. Therefore, the branched sulfone ketone polymer has excellent film formation in thin film production, and shows stability against redox.

More specifically, the organic-inorganic composite polymer electrolyte of the present invention preferably has a hydrogen ion conductivity of 4.23 × 10 ⁻³ S / cm or more, and preferably 4.23 × 10 ⁻³ to 9.96 × 10 ⁻³ S / cm, It is preferable that methanol transmittance is 1.75 * 10 <^-7> cm <^2> / sec or less, and it is more preferable that it is 0.961 * 10 <^-7> -1.75 * 10 <^-7> cm <^2> / sec. When the range of the hydrogen ion conductivity and the methanol permeability is satisfied, a direct methanol fuel cell (DMFC) polymer electrolyte may have a sufficient effect.

The organic-inorganic composite polymer electrolyte membrane according to the present invention showed a low methanol permeability and a low hydrogen ion conductivity at a low temperature, but increased hydrogen ion conductivity even at a high temperature compared to a low temperature. In particular, by adding inorganic particles such as hydrophilic silicon oxide, water uptake is also better.

In addition, the polymer electrolyte membrane for a fuel cell including the organic-inorganic composite polymer of the present invention can be produced by a solvent casting method.

As a preferable example, the organic-inorganic composite polymer and the inorganic particles may be dissolved in an organic solvent, cast using a flat glass plate, a round glass tube, or the like, and then dried in a vacuum oven at 120 to 150 ° C. Thus prepared polymer electrolyte membrane preferably has a thickness of 20 to 50 ㎛.

In this case, the content of the inorganic particles used in the organic-inorganic composite polymer of the present invention is preferably included in an amount of 0.1 to 14 parts by weight based on 100 parts by weight of the sulfonated polysulfone ketone copolymer in consideration of the cracking of the film.

The inorganic particles may be selected from the group consisting of silicon oxide, phosphato-antimonic acid, phosphoric acid, cesium (caesium), and phosphotungstic acid.

The inorganic particles used in the present invention may be produced in a uniform size by a conventional sol-gel method using a mixture containing an inorganic substance such as tetraethoxysilane, a base and an alcohol solution, and the method is not necessarily limited. .

The inorganic particles preferably have a size of 1 nm to 10 μm, more preferably 10 to 20 nm.

In addition, the sulfonated polysulfone ketone copolymer includes an aromatic sulfone repeating unit, an aromatic ketone repeating unit, and an aromatic compound repeating unit connecting the repeating unit with an ether bond, wherein the aromatic sulfone repeating unit, and the aromatic ketone repeating unit It is preferable that 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 mol% 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]

In the above formula, 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,

R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ are each independently aromatic 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 member selected from the group consisting of a ring 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 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.

More preferably, the polysulfone ketone copolymer of the present invention includes a molecular structure represented by the following Chemical Formula 6 or Chemical Formula 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, and more preferably 30,000 to 150,000 in terms of mechanical strength and hydrogen ion conductivity.

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 branching unit contains 0.1 mol% or more based on the total amount of the repeating units of the aromatic compound connecting the remaining repeating units by ether linkage. In order to prevent the fall of the workability by excessive crosslinking, it is preferable to be contained in 1 mol% or less.

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 is used to condense a monomer mixture comprising sulfonated or unsulfonated aromatic sulfone monomers, sulfonated or unsulfonated aromatic ketone monomers, and dihydroxy monomers in the presence of an organic solvent. It can be prepared by the method, wherein at least one or more 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 Formula 18, the aromatic ketone monomer is represented by Formula 19, the sulfonated aromatic sulfone monomer is represented by Formula 20, and the sulfonated aromatic ketone monomer is represented by It is represented by the formula (21), it is preferable that the aromatic dihydroxy 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 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,

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 30 carbon atoms containing one or more heteroatoms selected from the group consisting of oxygen, nitrogen, and sulfur. At least one selected from the group consisting of an aromatic ring 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 may be polymerized by further adding one or more polyfunctional monomers selected from the group consisting of compounds represented by Formulas 8 to 15 to the monomer mixture of a) to f). Can be prepared. The amount of the polyfunctional monomer added is based on the content of the branching units described above.

The organic-inorganic composite polymer 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 fuel cells.

Hereinafter, preferred examples will be described to aid in understanding the present invention. However, the following examples are merely to illustrate the present invention is not limited to the scope of the present invention.

EXAMPLE

Example 1

(Preparation of sulfonated aromatic ketone monomer)

30 g of 4,4'-difluorobezopenone was added to a 250 mL flask, and 75 mL of 35% fuming sulfuric acid was slowly added to completely dissolve the 4,4'-difluorobenzophenone. Next, the temperature was gradually heated and reacted at 110 ° C. for about 6 hours. The reaction solution was cooled to room temperature and poured into ice water or placed in an ice bath, and when the heat was completely cooled, an excess of NaOH was added to the mixture and neutralized. Thereafter, the mixture was cooled and Nag 90 g was added thereto to obtain a solid 3,3'-disodiumsulfonyl-4,4'-difluorobenzophenone. The obtained solid was filtered, dried and recrystallized. Recrystallization was carried out twice with isopropyl alcohol and water, and the total yield was about 75%.

¹ H NMR (300 mHz) δ7.3 (H, ortho H of fluorophenyl), δ7.7 (H, meta H of fluorophenyl), δ8.0 (H, ortho H of ketone). FTIR (KBr) 1664 cm ⁻¹ (C = O), 1259 cm ⁻¹ and 1093 cm ⁻¹ (S = O), 624 cm ⁻¹ (C = S).

Example 2

(Preparation of sulfonated aromatic sulfone monomer)

30 g of bis (4-fluorophenyl) sulfone was added to a 250 mL flask, and 75 mL of 30% fuming sulfuric acid was slowly added to completely dissolve the bis (4-fluorophenyl) sulfone. The mixture was slowly heated to react at 110 ° C. for about 6 hours. The reaction solution was cooled to room temperature and poured into ice water or placed in an ice bath, and when the heat was completely cooled, an excess of NaOH was added to the mixture to neutralize it. Thereafter, the mixture was cooled and Nag 90 g was added thereto to obtain a solid 3,3'-disodiumsulfonyl-4,4'-difluorophenylsulfone. The obtained solid was filtered, dried and recrystallized. Recrystallization was carried out in two steps using isopropyl alcohol and water, and the total yield was about 75%.

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). FTIR (KBr) 1093 cm ⁻¹ (S = O), 624 cm ⁻¹ (C = S).

Example 3

Synthesis of Branched Poly (Sulfone-Ketone) Copolymers

A Dean-stark trap and a condenser were installed in a 500 mL three-necked flask, and 0.1 mol of bisphenol A, 0.06 mol of 4,4'-difluorobenzophenone, and the 3,3'- obtained in Example 2. 0.04 mol of disodiumsulfonyl-4,4'-difluorophenylsulfone was dissolved in 150 mL of N-methylpyrrolidone (NMP), followed by 1,1,1-tris (4-hydroxyphenyl) ethane (1 , 1,1-tris (4-hydroxyphenyl) ethane) was added at 0.0003 mol (0.3 mol% of bisphenol A) to react under nitrogen.

Thereafter, K ₂ CO ₃ (0.26 mol) was added to the reaction mixture, and the temperature was raised to 70 ° C., 150 mL of toluene was added thereto, and the produced water was removed through reflux for 5 hours.

After removing water, toluene was removed while raising the temperature to 160 ° C. Thereafter, the reaction was further performed at 160 ° C. for about 6 hours to prepare a branched poly (sulfone-ketone) copolymer. The obtained branched poly (sulfone-ketone) copolymer was precipitated in 500 mL of a mixed solution of water and methanol (volume ratio = 1: 9) to obtain a solid. The viscosity of the obtained solid was about 0.3-0.5 g / dL.

(Production of Polymer Electrolyte Membrane)

The branched poly (sulfone-ketone) copolymer obtained above was dissolved in NMP, cast using a flat glass plate and a round glass tube, and dried in a vacuum oven (150 ° C.) to a brown having a thickness of 20-50 μm. A transparent membrane of was prepared. The membrane was immersed in hydrochloric acid solution (0.1 N) for 5 hours and then dried to measure membrane properties.

Example 4

(Silicon Oxide Synthesis of Nanoparticles)

250 ml of distilled water, 0.4 g of NaOH and 20 ml of ethanol were added to a 500 mL flask, followed by mixing for 30 minutes, and 40 ml of tetraethoxysilane (TEOS) was mixed for 24 hours. Then, the solvent was removed from the resultant to obtain silicon oxide (10-20 nm) of nanoparticles. In the present invention, in the preparation of the organic-inorganic composite film, the silicon oxide synthesized above was directly used.

Example 5

(Synthesis of Organic-Inorganic Composite Polymer Electrolyte Membrane)

0.4 g of the branched poly (sulfone-ketone) copolymer obtained in Example 3 and 0.016 g of the 15 nm silicon oxide (4 wt% of the polymer) obtained in Example 4 were dissolved in dimethyl sulfoxide and mixed.

Thereafter, the mixed solution was cast using a flat glass plate and a round glass tube, and then dried in a vacuum oven (150 ° C.) to prepare a brown transparent membrane having a thickness of 20-50 μm. The membrane was immersed in hydrochloric acid solution (0.1N) for 5 hours and then dried to measure membrane properties.

Example 6

(Synthesis of Organic-Inorganic Composite Polymer Electrolyte Membrane)

0.4 g of the branched poly (sulfone-ketone) copolymer obtained in Example 3 and 0.028 g of the 15 nm silicon oxide (7 wt% of the polymer) obtained in Example 4 were dissolved in dimethyl sulfoxide and mixed. Except, an organic-inorganic composite polymer electrolyte membrane was prepared in the same manner as in Example 5.

Example 7

(Synthesis of Organic-Inorganic Composite Polymer Electrolyte Membrane)

0.4 g of the branched poly (sulfone-ketone) copolymer obtained in Example 3 and 0.04 g of 15 nm silicon oxide (10 wt% of the polymer) obtained in Example 4 were dissolved and mixed in dimethyl sulfoxide. Except, an organic-inorganic composite polymer electrolyte membrane was prepared in the same manner as in Example 5.

Example 8

Synthesis of Poly (sulfone-ketone) Copolymer

Except for using 1,1,1-tris (4-hydroxyphenyl) ethane, the same method as in Example 3, except that the volume ratio of the mixture of water and methanol at 3: 7 was used at the time of precipitation of the obtained polymer. A poly (sulfone-ketone) copolymer and a polymer electrolyte membrane were prepared.

Example 9

(Synthesis of Organic-Inorganic Composite Polymer Electrolyte Membrane)

0.4 g of the poly (sulfone-ketone) copolymer obtained in Example 8 and 0.016 g of the 15 nm silicon oxide (4 wt% of the polymer) obtained in Example 4 were dissolved in dimethyl sulfoxide and mixed, except that a solution was used. The organic-inorganic composite polymer electrolyte membrane was prepared in the same manner as in Example 5.

Example 10

(Synthesis of Organic-Inorganic Composite Polymer Electrolyte Membrane)

0.4 g of the poly (sulfone-ketone) copolymer obtained in Example 8 and 0.028 g of a 15 nm silicon oxide (7 wt% of a polymer) obtained in Example 4 were dissolved in dimethyl sulfoxide and mixed. The organic-inorganic composite polymer electrolyte membrane was prepared in the same manner as in Example 5.

Example 11

(Synthesis of Organic-Inorganic Composite Polymer Electrolyte Membrane)

0.4 g of the poly (sulfone-ketone) copolymer obtained in Example 8 and 0.04 g of 15 nm silicon oxide (10 wt% of the polymer) obtained in Example 4 were dissolved in dimethyl sulfoxide and mixed. The organic-inorganic composite polymer electrolyte membrane was prepared in the same manner as in Example 5.

Example 12

(Synthesis of Branched Poly (Ketone-Sulfone) Copolymer)

0.1 mol of bisphenol A, 0.06 mol of 4,4'-difluorophenylsulfone, 0.04 mol of 3,3'-disodiumsulfonyl-4,4'-difluorobenzophenone obtained in Example 1, and 1,1 A mixed solution of water and methanol at the precipitation of the obtained polymer using 0.0003 mol (0.3% of bisphenol A) using 1,1,1-tris (4-hydroxyphenyl) ethane) A branched poly (ketone-sulfone) copolymer and a polymer electrolyte membrane were prepared in the same manner as in Example 3, except that the volume ratio of was 3: 7.

Example 13

(Synthesis of Organic-Inorganic Composite Polymer Electrolyte Membrane)

0.4 g of the branched poly (ketone-sulfone) copolymer obtained in Example 12 and 0.016 g of 15 nm silicon oxide (4 wt% of the polymer) obtained in Example 4 were dissolved and mixed in dimethyl sulfoxide. Except, an organic-inorganic composite polymer electrolyte membrane was prepared in the same manner as in Example 5.

Example 14

(Synthesis of Organic-Inorganic Composite Polymer Electrolyte Membrane)

0.4 g of the branched poly (ketone-sulfone) copolymer obtained in Example 12 and 0.028 g (7 wt% of a polymer) of 15 nm silicon oxide obtained in Example 4 were dissolved in dimethyl sulfoxide and mixed. Except, an organic-inorganic composite polymer electrolyte membrane was prepared in the same manner as in Example 5.

Example 15

(Synthesis of Organic-Inorganic Composite Polymer Electrolyte Membrane)

0.4 g of the branched poly (ketone-sulfone) copolymer obtained in Example 12 and 0.04 g of 15 nm silicon oxide (10 wt% of the polymer) obtained in Example 4 were dissolved in dimethyl sulfoxide and mixed. Except, an organic-inorganic composite polymer electrolyte membrane was prepared in the same manner as in Example 5.

Example 16

(Synthesis of Poly (ketone-Sulfone) Copolymer)

A poly (sulfone-ketone) copolymer and a polymer electrolyte membrane were prepared in the same manner as in Example 12, except that 1,1,1-tris (4-hydroxyphenyl) ethane was not used.

Example 17

(Synthesis of Organic-Inorganic Composite Polymer Electrolyte Membrane)

0.4 g of the poly (ketone-sulfone) copolymer obtained in Example 16 and 0.016 g of the 15 nm silicon oxide (4 wt% of the polymer) obtained in Example 4 were dissolved in dimethyl sulfoxide and mixed. The organic-inorganic composite polymer electrolyte membrane was prepared in the same manner as in Example 5.

Example 18

(Synthesis of Organic-Inorganic Composite Polymer Electrolyte Membrane)

0.4 g of the poly (ketone-sulfone) copolymer obtained in Example 16 and 0.028 g of a 15 nm silicon oxide (7 wt% of a polymer) obtained in Example 4 were dissolved in dimethyl sulfoxide and mixed. The organic-inorganic composite polymer electrolyte membrane was prepared in the same manner as in Example 5.

Example 19

(Synthesis of Organic-Inorganic Composite Polymer Electrolyte Membrane)

0.4 g of the poly (ketone-sulfone) copolymer obtained in Example 16 and 0.04 g of 15 nm silicon oxide (10 wt% of the polymer) obtained in Example 4 were dissolved in dimethyl sulfoxide and mixed. The organic-inorganic composite polymer electrolyte membrane was prepared in the same manner as in Example 5.

Comparative Example 1

A polymer electrolyte membrane was prepared in the same manner as in Example 5, except that 0.06 g of silicon oxide (15 wt% of polymer) was used for 0.4 g of the branched poly (sulfone-ketone) copolymer obtained in Example 3. However, it was not possible to measure the properties of the film due to the cracking of the film.

Comparative Example 2

A polymer electrolyte membrane was prepared in the same manner as in Example 5, except that 0.06 g of silicon oxide (15 wt% of polymer) was used for 0.4 g of the poly (sulfone-ketone) copolymer obtained in Example 8. However, it was difficult to produce a film because silicon oxides were entangled with each other in the film production, and distribution was not properly performed.

Comparative Example 3

A polymer electrolyte membrane was prepared in the same manner as in Example 5, except that 0.06 g of silicon oxide (15 wt% of polymer) was used for 0.4 g of the branched poly (ketone-sulfone) copolymer obtained in Example 12. However, this also could not measure the properties of the film due to the cracking of the film.

Comparative Example 4

A polymer electrolyte membrane was prepared in the same manner as in Example 5, except that 0.06 g of silicon oxide (15 wt% of polymer) was used for 0.4 g of the poly (ketone-sulfone) copolymer obtained in Example 16. However, it was difficult to produce a film because silicon oxides were entangled with each other in the film production, and distribution was not properly performed.

Comparative Example 5

As described above, since the polymer electrolyte membrane could not be prepared in Comparative Examples 1 to 4, Nafion 112, which was previously used commercially, was used as the polymer electrolyte membrane.

Comparative Example 6

Nafion 115, which is currently used commercially, was used as the polymer electrolyte membrane, and methanol permeability and hydrogen ion conductivity results thereof are shown in FIGS. 1 and 2.

1 and 2, when tetraethoxysilane (TEOS) was added to Nafion 115 in the prior art, methanol permeability decreased with increasing amount, and hydrogen ion conductivity also showed a tendency to decrease. However, since the hydrogen ion conductivity decreases with the silicon oxide content in general, the increase in the silicon oxide 10% content in FIGS. 1 and 2 does not mean that the hydrogen ion conductivity is improved. It is hard to say that the increase is due to entering the margin of error.

Experimental Example 1

The proton conductivity of the polymer electrolyte membranes of Examples 4 to 19 and Comparative Example 5 was measured. Hydrogen ion conductivity was measured by placing a polymer film between electrodes of 2.54 cm 2, and measuring the initial resistance at 30 ° C. using a potentiometer. The measurement formula is the same as the following formula 1, the measurement results are shown in Table 1. At this time, the initial conductivity represents the initial resistance value 1 / ohm.

(Calculation 1)

Hydrogen ion conductivity (S / cm) = [film thickness (cm) / area (cm 2)] x initial conductivity (S)

Experimental Example 2

In order to measure the permeability of methanol, the polymer electrolyte membranes of Examples 4 to 19 and Comparative Example 5 were placed in the middle of the two cells and fixed using an epoxy adhesive. Thereafter, 15 mL of 1 mol of aqueous methanol solution was added to one cell, and 15 mL of distilled water was added to the other cell, and then, 10 μl was collected once every 10 minutes from a cell containing distilled water, and 10 μl of distilled water was added thereto. Adjusted to 10 mL. The aliquot sample was measured for methanol concentration using gas chromatography. In addition, a graph of methanol change over time was prepared, and the permeability was calculated by the following formula 2 as a slope, and the results are shown in Table 1.

(Calculation 2)

MeOH permeability (cm 2 / S) = [Slope (ppm / s) x solution volume (15 cm 3) x membrane thickness (cm)] / [membrane area (7.06 cm 2) x MeOH concentration (32000 ppm)]

In Formula 2, the fixed value was 3 cm in diameter of the membrane, 1 mol of MeOH concentration (32000 ppm), and 15 mL of volume of the solution.

Experimental Example 3

The polymer electrolyte membranes of Examples 4 to 19 and Comparative Example 5 were immersed in distilled water and left at 30 ° C. for 24 hours. After 24 hours, the polymer membrane was taken out and weighed (M _wet ), the membrane was put in an oven at 100 ° C., dried for 24 hours, weighed again (M _dry ), and the water-up take was calculated by the following equation 3, Is shown in Table 1.

(Calculation 3)

Water-up take (%) = [(M _wet -M _dry ) / M _dry ]

TABLE 1

   division    Hydrogen ion conductivity (S / cm)    Methanol transmittance (㎠ / s)    Water-up take (%)  Comparative Example 5 15.68 × 10 ^-3 21.7 × 10 ^-7        29.5    Example    4 6.35 × 10 ^-3 1.48 × 10 ^-7        54.74    5 7.37 × 10 ^-3 1.50 × 10 ^-7        62.03    6 7.32 × 10 ^-3 1.32 × 10 ^-7        65.24    7 4.76 × 10 ^-3 1.20 × 10 ^-7        63.23    8 8.8 × 10 ^-3 4.23 × 10 ^-7        47.35    9 9.96 × 10 ^-3 1.75 × 10 ^-7        53.21    10 9.5 × 10 ^-3 1.08 × 10 ^-7        56.11    11 7.5 × 10 ^-3 1.53 × 10 ^-7        54.26    12 9.23 × 10 ^-3 3.20 × 10 ^-7        24.30    13 6.09 × 10 ^-3 1.36 × 10 ^-7        24.58    14 5.12 × 10 ^-3 1.17 × 10 ^-7        22.45    15 4.23 × 10 ^-3 1.05 × 10 ^-7        25.48    16 9.63 × 10 ^-3 3.17 × 10 ^-7        26.38    17 7.45 × 10 ^-3 1.52 × 10 ^-7        26.79    18 7.17 × 10 ^-3 0.968 × 10 ^-7        26.44    19 4.98 × 10 ^-3 0.961 × 10 ^-7        26.81

As described above, according to the present invention, a polymer electrolyte membrane is prepared by adding inorganic particles such as silicon oxide to a poly (sulfone-ketone) copolymer or a poly (ketone-sulfone) copolymer, thereby producing hydrogen in comparison with a conventional polymer electrolyte membrane. The ion conductivity is excellent, and in particular, the methanol permeability is greatly reduced to improve the performance of the membrane, and thus the effect of extending the life can be obtained.

Claims (13)

The organic-inorganic composite polymer comprising inorganic particles in an amount of 0.1 to 14 parts by weight based on 100 parts by weight of the sulfonated polysulfone ketone copolymer. According to claim 1, wherein the inorganic particles are a group consisting of silicon oxide, phosphato-antimonic acid, phosphoric acid, cesium (phosphesungung) and phosphotungstic acid of 1 nm to 10 ㎛ size Will be selected from, organic-inorganic composite polymer. The method of claim 1, wherein the sulfonated polysulfone ketone copolymer 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, At least one or more of the aromatic ketone repeating units having 1 to 50 mol% of sulfonic acid or sulfonate substituents, organic-inorganic composite polymer. The method of claim 3, wherein 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, an organic-inorganic composite polymer: [Formula 1]

[Formula 2]

[Formula 3]

[Formula 4]

[Formula 5]

In the above formula, 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 , R ⁵ , R ⁶ and R ⁷ are each independently aromatic 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 member selected from the group consisting of a ring 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 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 organic-inorganic composite polymer of claim 1, wherein the sulfonated polysulfone ketone copolymer includes a molecular structure represented by the following Chemical Formula 6 or Chemical Formula 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 to 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 organic-inorganic composite polymer of claim 1, wherein the sulfonated polysulfone ketone copolymer has a weight average molecular weight of 10,000 to 200,000. The method of claim 1, The sulfonated polysulfone ketone copolymer is an organic-inorganic, 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 Formulas 8 to 15 Composite Polymers: [Formula 8]

[Formula 9]

[Formula 10]

[Formula 11]

[Formula 12]

[Formula 13]

[Formula 14]

[Formula 15]

. The organic-inorganic composite polymer of claim 7, wherein the branching unit is included in an amount of 0.1 to 1 mol% based on an aromatic compound repeating unit connecting the aromatic ketone and the aromatic sulfone repeating unit by an ether bond. The organic-inorganic composite polymer of claim 7, wherein the sulfonated polysulfone ketone copolymer 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 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 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 to 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, wherein the sulfonated polysulfone ketone copolymer Condensation of a monomer mixture comprising a sulfonated or unsulfonated aromatic sulfone monomer, a sulfonated or unsulfonated aromatic ketone monomer, and an aromatic dihydroxy monomer 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 sulfonated aromatic sulfone monomer is represented by the following formula (20), The sulfonated aromatic ketone monomer is represented by the following formula 21, The aromatic dihydroxy monomer is represented by the following formula 22, an organic-inorganic composite polymer: [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, 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 each independently have 5 to 30 carbon atoms containing one or more heteroatoms selected from the group consisting of oxygen, nitrogen, and sulfur. At least one selected from the group consisting of an aromatic ring 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 each independently an integer of 0-3, y and y' are each independently an integer of 1-4, and x + y and x '+ y' are each independently an integer of 1-4. The organic-inorganic composite polymer according to claim 10, wherein the monomer mixture 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]

A polymer electrolyte membrane for a fuel cell comprising the organic-inorganic composite polymer according to any one of claims 1 to 11. The polymer electrolyte membrane of Claim 12, wherein the polymer electrolyte membrane is prepared by a solvent casting method and has a thickness of 20 to 50 µm.

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