KR20110084849A - Porous support and polymer electrolyte membrane for fuel cell including the same - Google Patents

Abstract

PURPOSE: A porous support is provided to ensure excellent mechanical properties, dimensional stability and chemical resistance and to improve hydrogen ion conductivity of a polymer electrolyte membrane for a fuel cell. CONSTITUTION: A porous support includes the polymer induced from polyamic acids or the polymer induced from polyimides. The porous support has micropores and picopores present in the polymer induced from polyamic acids or picopores present in the polymer induced from polyimides. The porous support comprises repeating units produced from aromatic diamine and dianhydride having at least one functional group existing at an ortho position of the polyamic acids and polyimides.

Description

POROUS SUPPORT AND POLYMER ELECTROLYTE MEMBRANE FOR FUEL CELL INCLUDING THE SAME

The present invention relates to a porous support and a polymer electrolyte membrane for a fuel cell comprising the same.

A fuel cell is a power generation system that directly converts chemical reaction energy of hydrogen and oxygen contained in hydrocarbon-based materials such as methanol, ethanol, and natural gas into electrical energy. Such fuel cells are drawing attention as a clean energy source that can replace fossil energy.

Representative examples of the fuel cell include a polymer electrolyte membrane fuel cell (PEMFC) and a direct oxidation fuel cell. When methanol is used as a fuel in the direct oxidation fuel cell, it is called a direct methanol fuel cell (DMFC).

In such a fuel cell system, a stack that substantially generates electricity has a structure in which several to tens of unit cells including a membrane-electrode assembly (MEA) and a separator are stacked. The membrane-electrode assembly has a structure in which an anode and a cathode face each other with a polymer electrolyte membrane including a cation exchange resin having hydrogen ion conductivity therebetween.

The principle of generating electricity in a fuel cell is that fuel is supplied to an anode, which is a fuel electrode, adsorbed to a catalyst of the anode, and fuel is ionized by an oxidation reaction, and electrons are generated. On reaching it, hydrogen ions pass through the polymer electrolyte membrane and are delivered to the cathode. An oxidant is supplied to the cathode, and the oxidant, hydrogen ions, and electrons react on the catalyst of the cathode to generate electricity while producing water.

Currently, researches are being actively conducted to improve hydrogen ion conductivity, mechanical properties, dimensional stability, and chemical resistance of the polymer electrolyte membrane.

A porous support having excellent mechanical properties, dimensional stability and chemical resistance, and a polymer electrolyte for a fuel cell, including the porous support, and having excellent hydrogen ion conductivity, mechanical properties, dimensional stability and chemical resistance, and capable of improving the output density of a fuel cell. It provides a membrane, and provides a method for producing the porous support and the polymer electrolyte membrane for the fuel cell.

It provides a membrane-electrode assembly comprising the porous support and the polymer electrolyte membrane for the fuel cell, and provides a fuel cell system comprising the membrane-electrode assembly.

According to one aspect of the invention, the porous support comprises a polymer derived from polyamic acid or a polymer derived from polyimide. The porous support has micropores and picopores present in the polymer derived from the polyamic acid or picopores present in the polymer derived from the polyimide, wherein the polyamic acid and the polyimide have an ortho position relative to an amine group. Repeating units prepared from aromatic diamines and dianhydrides comprising at least one functional group present in.

The functional group may comprise OH, SH or NH ₂ .

The polymer is induced by thermal conversion from the polyamic acid or the polyimide, and the ratio of the thermally converted repeating unit to the total amount (100 mol%) of the repeating unit included in the polyamic acid or the polyimide (thermal conversion rate) ) May be about 10 mol% to about 100 mol%.

The polymer derived from the polyamic acid and the polymer derived from the polyimide may have a free volume degree (FFV) of about 0.18 to about 0.40.

In addition, the polymer derived from the polyamic acid and the polymer derived from the polyimide may have an interplanar distance by XRD measurement in the range of about 550 pm to about 800 pm.

Two or more picopores may be connected to each other to form an hourglass shape.

In addition, the picopores may have a full width at half maximum (FWHM) of about 10 pm to about 40 pm by positron annihilation lifetime spectroscopy (PALS) measurement.

The porous support may have a porosity of about 10% by volume to about 95% by volume relative to the total volume of the support. In addition, the porous support may be formed to a thickness of about 10 ㎛ to about 200 ㎛.

The polyamic acid is a polyamic acid including a repeating unit represented by the following Chemical Formulas 1 to 4, a polyamic acid copolymer comprising a repeating unit represented by the following Chemical Formulas 5 to 8, copolymers thereof, and blends thereof It may be selected, the polyimide is a polyimide containing a repeating unit represented by the following formula 19 to 22, a polyimide copolymer comprising a repeating unit represented by the following formula 23 to 26, copolymers thereof and their It can be selected from the group consisting of blends.

[Formula 1]

[Formula 2]

(3)

[Formula 4]

[Chemical Formula 5]

[Formula 6]

[Formula 7]

[Formula 8]

[Formula 19]

[Formula 20]

[Formula 21]

[Formula 22]

(23)

[Formula 24]

[Formula 25]

[Formula 26]

In Chemical Formulas 1 to 8 and 19 to 26,

Ar ₁ is an aromatic ring group selected from a substituted or unsubstituted tetravalent C6 to C24 arylene group and a substituted or unsubstituted tetravalent C4 to C24 heterocyclic group, wherein the aromatic ring group is present alone; Two or more are joined to each other to form a condensed ring; Two or more single bonds, O, S, C (= 0), CH (OH), S (= 0) ₂ , Si (CH ₃ ) ₂ , (CH ₂ ) _p (where 1 ≦ _p ≦ 10) , (CF ₂ ) _q (where 1 ≦ _q ≦ 10), C (CH ₃ ) ₂ , C (CF ₃ ) ₂ or C (═O) NH, and

Ar ₂ is an aromatic ring group selected from a substituted or unsubstituted divalent C6 to C24 arylene group and a substituted or unsubstituted divalent C4 to C24 heterocyclic group, wherein the aromatic ring group is present alone; Two or more are joined to each other to form a condensed ring; Two or more single bonds, O, S, C (= 0), CH (OH), S (= 0) ₂ , Si (CH ₃ ) ₂ , (CH ₂ ) _p (where 1 ≦ _p ≦ 10) , (CF ₂ ) _q (where 1 ≦ _q ≦ 10), C (CH ₃ ) ₂ , C (CF ₃ ) ₂ or C (═O) NH, and

Q is O, S, C (= O), CH (OH), S (= O) ₂ , Si (CH ₃ ) ₂ , (CH ₂ ) _p (where 1 ≦ _p ≦ 10), (CF ₂ ) _q (where 1 ≦ _q ≦ 10), C (CH ₃ ) ₂ , C (CF ₃ ) ₂ , C (═O) NH, C (CH ₃ ) (CF ₃ ), or a substituted or unsubstituted phenylene group Wherein the substituted phenylene group is substituted with a C1 to C6 alkyl group or a C1 to C6 haloalkyl group, wherein Q is linked to both aromatic rings in the mm, mp, pm, or pp position,

Y is the same or different at each repeating unit, each independently OH, SH or NH ₂ ,

n is an integer satisfying 20 ≦ n ≦ 200,

m is an integer satisfying 10≤m≤400,

l is an integer satisfying 10 ≦ l ≦ 400.

The molar ratio between each repeating unit in the copolymer of the polyamic acid including the repeating unit represented by the formula 1 to 4, the molar ratio of m: l in the formula 5 to 8, the repeating unit represented by the formula 19 to 22 The molar ratio between each repeating unit in the copolymer of the polyimide including or the molar ratio of m: l in the above formulas 23 to 26 may be about 0.1: 9.9 to about 9.9: 0.1.

The polymer derived from the polyamic acid and the polymer derived from the polyimide may include a polymer including a repeating unit represented by any one of Formulas 37 to 50 or a copolymer thereof.

[Formula 37]

[Formula 38]

[Formula 39]

[Formula 40]

[Formula 41]

[Formula 42]

[Formula 43]

[Formula 44]

[Formula 45]

[Formula 46]

[Formula 47]

[Formula 48]

[Formula 49]

[Formula 50]

In Chemical Formulas 37 to 50,

_{Ar 1, Ar 2, Q,} n, m and l are the same as described in each of the above Chemical Formulas 1 to 8 and Chemical Formulas 19 to 26, _{Ar 1, Ar 2, Q,} n, m and l,

Ar ₁ ′ is an aromatic ring group selected from a substituted or unsubstituted divalent C6 to C24 arylene group and a substituted or unsubstituted divalent C4 to C24 heterocyclic group, wherein the aromatic ring group is present alone; Two or more are joined to each other to form a condensed ring; Two or more single bonds, O, S, C (= 0), CH (OH), S (= 0) ₂ , Si (CH ₃ ) ₂ , (CH ₂ ) _p (where 1 ≦ _p ≦ 10) , (CF ₂ ) _q (where 1 ≦ _q ≦ 10), C (CH ₃ ) ₂ , C (CF ₃ ) ₂ or C (═O) NH, and

Y '' is O or S.

In Formulas 1 to 8, 19 to 26, and 37 to 50, examples of Ar ₁ may be selected from those represented by the following formulas.

Where

X ₁ , X ₂ , X ₃ and X ₄ are the same or different from each other and each independently O, S, C (= 0), CH (OH), S (= 0) ₂ , Si (CH ₃ ) ₂ , ( CH ₂ ) _p (where 1 ≦ _p ≦ 10), (CF ₂ ) _q (where 1 ≦ _q ≦ 10), C (CH ₃ ) ₂ , C (CF ₃ ) ₂ , or C (═O) NH ego,

W ₁ and W ₂ are the same or different and are each independently O, S, or C (═O),

Z ₁ is O, S, CR ₁₀₀ R ₁₀₁ or NR ₁₀₂ , wherein R ₁₀₀ , R ₁₀₁ and R ₁₀₂ are the same or different from each other and are each independently hydrogen or a C1 to C5 alkyl group,

Z ₂ and Z ₃ are the same or different from each other and independently of each other N or CR ₁₀₃ (wherein R ₁₀₃ is hydrogen or a C1 to C5 alkyl group) but not CR ₁₀₃ at the same time,

R ₁ to R ₄₂ are the same or different and are each independently hydrogen or a substituted or unsubstituted C1 to C10 aliphatic organic group,

k1 to k3, k8 to k14, k24 and k25 are integers of 0 to 2,

k5, k15, k16, k19, k21 and k23 are integers of 0 or 1,

k4, k6, k7, k17, k18, k20, k22, k26 to k29, k31, k34 to k36, k38, k39 and k42 are integers from 0 to 3,

k30, k37, k40 and k41 are integers from 0 to 4,

k32 and k33 are integers of 0-5.

In Formulas 1 to 8, 19 to 26, and 37 to 50, specific examples of Ar ₁ may be selected from those represented by the following formulas.

In Formulas 1 to 8 and 19 to 32, examples of Ar ₂ may be selected from those represented by the following formulas.

Where

X ₁ , X ₂ , X ₃ and X ₄ are the same or different from each other and each independently O, S, C (= 0), CH (OH), S (= 0) ₂ , Si (CH ₃ ) ₂ , ( CH ₂ ) _p (where 1 ≦ _p ≦ 10), (CF ₂ ) _q (where 1 ≦ _q ≦ 10), C (CH ₃ ) ₂ , C (CF ₃ ) ₂ , or C (═O) NH ego,

W ₁ and W ₂ are the same or different and are each independently O, S, or C (═O),

Z ₁ is O, S, CR ₁₀₀ R ₁₀₁ or NR ₁₀₂ , wherein R ₁₀₀ , R ₁₀₁ and R ₁₀₂ are the same or different from each other and are each independently hydrogen or a C1 to C5 alkyl group,

Z ₂ and Z ₃ are the same or different from each other and independently of each other N or CR ₁₀₃ (wherein R ₁₀₃ is hydrogen or a C1 to C5 alkyl group) but not CR ₁₀₃ at the same time,

R ₄₃ to R ₈₉ are the same or different from each other and are each independently hydrogen, a substituted or unsubstituted C1 to C10 aliphatic organic group, or a metal sulfonate group,

k43, k49, k64 to k68, k72 to k76, and k82 to k89 are integers of 0 to 4,

k44 to k46, k48, k51, k54, k55, k57, k58, k61 and k63 are integers from 0 to 3,

k47, k52, k53, k56, k59, k60, k62, k70, k78, k80 and k81 are integers from 0 to 2,

k50 is an integer of 0 or 1,

k69, k71, k77 and k79 are integers of 0-5.

In Formulas 1 to 8, 19 to 26, and 37 to 50, specific examples of Ar ₂ may be selected from those represented by the following formulas.

In the above formula, M is a metal, and the metal may be sodium, potassium, lithium, alloys thereof, or a combination thereof.

In Formulas 1 to 8, 19 to 26, and 37 to 50, examples of Q include C (CH ₃ ) ₂ , C (CF ₃ ) ₂ , O, S, S (= 0) ₂ or C (= 0). ) Can be selected from.

In Formulas 37 to 50, examples and specific examples of Ar ₁ 'are the same as those mentioned for the examples and specific examples of Ar ₂ of Formulas 1 to 8, 19 to 26, and 37 to 50.

In Formulas 1 to 8 and 19 to 26, Ar ₁ may be a functional group represented by any one of Formulas A1 to A8, Ar ₂ may be a functional group represented by any one of Formulas B1 to B11, and Q is C (CF ₃ ) ₂ .

[Formula A1] [Formula A2] [Formula A3]

[Formula A4] [Formula A5] [Formula A6]

                  Formula A7 Formula A8

[Formula B1] [Formula B2] [Formula B3]

[Formula B4] [Formula B5] [Formula B6] [Formula B7]

Formula B8 Formula B9

[Formula B10] [Formula B11]

In Formulas 37 to 50, Ar ₁ may be a functional group represented by any one of Formulas A1 to A8, Ar ₁ ′ may be a functional group represented by any one of Formulas C1 to C8, and Ar ₂ may be represented by Formula B1 It may be a functional group represented by any one of B11 to, and Q may be C (CF ₃ ) ₂ .

[Formula C1] [Formula C2] [Formula C3]

[Formula C4] [Formula C5] [Formula C6]

Formula C7 Formula C8

The porous support may include a fiber including a polymer having the picopores, and the fibers may be randomly arranged.

On the other hand, the porous support may include a fiber comprising a polymer having the picopores, the fibers may be arranged in one direction.

According to another aspect of the invention, the porous support; And it provides a polymer electrolyte membrane for a fuel cell comprising a cation exchange resin formed on the inside, the surface, or the inside and the surface of the porous support.

The cation exchange resin may be a polymer including a cation exchange group selected from the group consisting of sulfonic acid groups, carboxylic acid groups, phosphoric acid groups, phosphonic acid groups, and derivatives thereof.

In the polymer electrolyte membrane for fuel cells, the porous support and the cation exchange resin may be included in a weight ratio of about 99: 1 to about 10:90.

According to another aspect of the present invention, there is provided a polymer electrolyte membrane for a fuel cell including the porous support and formed with an acid doped into the inside, the surface, or the inside and the surface of the porous support.

The doped acid may be selected from the group consisting of sulfonic acid, carboxylic acid, phosphoric acid, phosphonic acid, and derivatives thereof.

According to another aspect of the present invention, there is provided a polymer electrolyte membrane for a fuel cell including a porous support and a fluorine group on the surface of the porous support.

The fuel cell polymer electrolyte membrane may be formed to a thickness of about 20 μm to about 300 μm.

According to another aspect of the invention, a polyamic acid or polyimide having a repeating unit prepared from an aromatic diamine and dianhydride comprising at least one functional group present in the ortho position relative to the amine group; And it provides a composition for forming a porous support comprising an organic solvent. The organic solvent is dimethyl sulfoxide; N-methyl-2-pyrrolidone; N-methylpyrrolidone; N, N-dimethylformamide; N, N-dimethylacetamide; ketones selected from the group consisting of γ-butyrolactone, cyclohexanone, 3-hexanone, 3-heptanone, and 3-octanone; And it is selected from the group consisting of a combination thereof.

The composition for forming a porous support includes about 1 wt% to about 40 wt% of the polyamic acid or the polyimide, and about 60 wt% to about 99 wt% of the organic solvent, based on the total amount of the composition for forming a porous support. can do.

The composition for forming the porous support is water; Alcohols selected from the group consisting of methanol, ethanol, 2-methyl-1-butanol, 2-methyl-2-butanol, glycerol, ethylene glycol, diethylene glycol and propylene glycol; Ketones selected from the group consisting of acetone and methylethyl ketone; A polymer compound selected from the group consisting of polyvinyl alcohol, polyacrylic acid, polyacrylamide, polyethylene glycol, polypropylene glycol, chitosan, chitin, dextran and polyvinylpyrrolidone; Tetrahydrofuran; Trichloroethane; And it may further comprise an adjuvant selected from the group consisting of a combination thereof. In this case, the composition for forming the porous support is about 1% to about 40% by weight of the polyamic acid or the polyimide and about 10% by weight of the organic solvent based on the total amount of the composition for forming the porous support including the auxiliary agent. About 95% by weight, and about 4% to about 70% by weight of the adjuvant.

The polyamic acid and the polyimide may each have a weight average molecular weight (Mw) of about 10,000 g / mol to about 500,000 g / mol.

The composition for forming the porous support may have a viscosity of about 0.01 Pa · s to about 100 Pa · s.

According to another aspect of the invention, the step of electrospinning the composition for forming the porous support to form a nonwoven fabric; And heat treating the nonwoven fabric to form a porous support including a polymer derived from a polyamic acid or a polymer derived from a polyimide.

According to another aspect of the invention, the step of electrospinning the composition for forming the porous support to form a nonwoven fabric; Heat treating the nonwoven fabric to form a porous support comprising a polymer derived from polyamic acid or a polymer derived from polyimide; And it provides a method for producing a polymer electrolyte membrane for a fuel cell comprising the step of forming a cation exchange resin on the inside, surface, or the inside and the surface of the porous support.

According to another aspect of the invention, the step of electrospinning the composition for forming the porous support to form a nonwoven fabric; Heat treating the nonwoven fabric to form a porous support comprising a polymer derived from polyamic acid or a polymer derived from polyimide; And it provides a method for producing a polymer electrolyte membrane for a fuel cell comprising the step of doping the acid on the inside, the surface, or the inside and the surface of the porous support.

The acid may be selected from the group consisting of sulfonic acid, carboxylic acid, phosphoric acid, phosphonic acid and derivatives thereof.

According to another aspect of the invention, the step of electrospinning the composition for forming a porous support to form a nonwoven fabric; Heat treating the nonwoven fabric to form a porous support comprising a polymer derived from polyamic acid or a polymer derived from polyimide; And it provides a method for producing a polymer electrolyte membrane for a fuel cell comprising the step of introducing a fluorine group on the surface of the porous support.

The electrospinning may be performed by applying a voltage of about 1 kV to about 1,000 kV.

The nonwoven fabric formed by the electrospinning may be randomly arranged fibers including the composition for forming a porous support.

On the other hand, the non-woven fabric formed by the electrospinning may be a fiber comprising a composition for forming a porous support may be arranged in one direction.

The polymer is induced by thermal conversion from the polyamic acid or the polyimide, and the ratio of the thermally converted repeating unit to the total amount (100 mol%) of the repeating unit included in the polyamic acid or the polyimide (thermal conversion rate) ) May be about 10 mol% to about 100 mol%.

The heat treatment may be carried out at a temperature of about 250 ℃ to about 550 ℃, it may be carried out for about 10 minutes to about 5 hours. In addition, the temperature increase rate during the heat treatment may be about 1 ℃ / min to about 20 ℃ / min.

According to another aspect of the invention, the anode and the cathode located opposite each other; And a membrane-electrode assembly positioned between the anode and the cathode and including the polymer electrolyte membrane for the fuel cell.

According to another aspect of the present invention, an electric generator including one or more of the membrane-electrode assembly and the separator, and generates electricity through the electrochemical reaction of the fuel and the oxidant; A fuel supply unit supplying fuel to the electricity generation unit; And an oxidant supply unit supplying an oxidant to the electricity generation unit.

Other aspects of the present invention are included in the following detailed description.

The porous support has excellent mechanical properties, dimensional stability, and chemical resistance, and the polymer electrolyte membrane for fuel cells has excellent hydrogen ion conductivity, mechanical properties, dimensional stability, and chemical resistance, and also has excellent fuel barrier property, and fuel cell. It can improve the output density.

1 is a view schematically showing a membrane-electrode assembly for a fuel cell according to an embodiment of the present invention.
2 is a view schematically showing the structure of a fuel cell system according to another embodiment of the present invention.
3 is a photograph of the porous support prepared in Example 4.
4 is a photograph of a polymer electrolyte membrane for a fuel cell prepared in Example 4. FIG.

Hereinafter, embodiments of the present invention will be described in detail. However, this is presented as an example, by which the present invention is not limited and the present invention is defined only by the scope of the claims to be described later.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. In the description using the drawings, like reference numerals designate like parts throughout the specification.

Unless otherwise defined herein, "picopores" refers to pores having an average diameter of pores of several hundred picometers, specifically, about 100 pm to about 1,000 pm, and "microporous pores" means an average diameter of pores. By pore is about 2 nm to about 50 μm, specifically about 10 nm to about 10 μm.

Unless otherwise defined herein, the term "substituted" or "substituted" means that the hydrogen atom in the compound or functional group is composed of C1 to C10 alkyl group, C1 to C10 alkoxy group, C1 to C10 haloalkyl group, and C1 to C10 haloalkoxy group It means substituted with one or more substituents selected from "hetero ring group" is one to three hetero atoms selected from the group consisting of O, S, N, P, Si and combinations thereof in one ring Containing, substituted or unsubstituted C2 to C30 cycloalkyl group, substituted or unsubstituted C2 to C30 cycloalkenyl group, substituted or unsubstituted C2 to C30 cycloalkynyl group, substituted or unsubstituted C2 to C30 hetero Aryl group, substituted or unsubstituted C2 to C30 cycloalkylene group, substituted or unsubstituted C2 to C30 cycloalkenylene group, substituted or unsubstituted C2 to C30 cyclo Kinil means group, or a substituted or unsubstituted C2 to C30 heteroarylene group ring.

Unless otherwise defined herein, an "aliphatic organic group" is a C1 to C30 alkyl group, a C2 to C30 alkenyl group, or a C2 to C30 alkynyl group, specifically a C1 to C15 alkyl group, a C2 to C15 alkenyl group, or It is a C2-C15 alkynyl group, More specifically, it is a C1-C10 alkyl group, a C2-C10 alkenyl group, or a C2-C10 alkynyl group.

Unless otherwise defined herein, “combination” means mixed or copolymerized. In addition, "copolymerization" means block copolymerization to random copolymerization, and "copolymer" means block copolymer to random copolymerization.

1 is a view schematically showing a membrane-electrode assembly for a fuel cell according to an embodiment of the present invention.

Referring to FIG. 1, the membrane-electrode assembly 20 for a fuel cell includes an anode 22, a polymer electrolyte membrane 24, and a cathode 26.

The anode 22 and the cathode 26 include an electrode substrate and a catalyst layer formed on the electrode substrate.

By the presence of the catalyst layer, the anode can promote the oxidation reaction of the fuel, the cathode can promote the reaction of the oxidant, hydrogen ions and electrons supplied to the cathode, thereby improving the efficiency of the fuel cell.

Examples of the catalyst included in the catalyst layer include platinum, ruthenium, osmium, platinum-ruthenium alloy, platinum-osmium alloy, platinum-palladium alloy, platinum-M alloy (where M is gallium (Ga), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), tin (Sn), molybdenum (Mo), tungsten (W), rhodium (Rh), ruthenium (Ru), and combinations thereof, and combinations thereof, but is not limited thereto. More specific examples of the catalyst include Pt, Pt / Ru, Pt / W, Pt / Ni, Pt / Sn, Pt / Mo, Pt / Pd, Pt / Fe, Pt / Cr, Pt / Co, Pt / Ru / W And Pt / Ru / Mo, Pt / Ru / V, Pt / Fe / Co, Pt / Ru / Rh / Ni, and Pt / Ru / Sn / W.

The catalyst may be used as the catalyst itself (black), or may be supported on a carrier. As the carrier, carbon-based materials such as graphite, denka black, ketjen black, acetylene black, carbon nanotube, carbon nanofiber, carbon nanowire, carbon nanoball, or activated carbon may be used, or alumina, silica, zirconia, Inorganic fine particles such as titania may also be used, but are not limited thereto.

The polymer electrolyte membrane 24 for the fuel cell is positioned between the anode 22 and the cathode 26, and has a porous support 244 and a cation exchange resin present inside, on the surface, or inside and the surface of the porous support 244 ( 242). The cation exchange resin 242 may have a cation conductivity, for example, hydrogen ion conductivity.

The polymer electrolyte membrane 24 is an insulator that electrically separates the anode 22 and the cathode 26, but acts as a medium for transferring hydrogen ions from the anode 22 to the cathode 26 during battery operation, and simultaneously reacts. It serves to separate gas or liquid.

The polymer electrolyte membrane 24 may include the porous support 244 to electrically separate the anode 22 and the cathode 26, and may have excellent mechanical properties and dimensional stability. This may facilitate the stack construction of the membrane-electrode assembly including the same.

The porous support 244 includes a polymer derived from polyamic acid or a polymer derived from polyimide. The polyamic acid, the polyimide, and the polymer derived therefrom will be described later. The porous support 244 has micropores and picopores present in the polymer derived from the polyamic acid or picopores present in the polymer derived from the polyimide, wherein the polyamic acid and the polyimide have an amine group. Repeat units made from aromatic diamines and dianhydrides comprising at least one functional group present at the ortho position. As a result, the porous support 244 may have a high porosity and thus efficiently include a cation exchange resin in the pores, thereby allowing a cation such as hydrogen ions to be easily transferred from the anode 22 to the cathode 26, thereby providing fuel. The efficiency of the battery can be improved. In particular, when the cation exchange resin is adsorbed to the picopores of the porous support 244 or the acid is doped, the adsorbed cation exchange resin and the doped acid are hardly separated from the porous support body. This makes it possible to transfer cations such as hydrogen ions from the anode 22 to the cathode 26 more stably, thereby improving the efficiency and life characteristics of the fuel cell.

The functional group present in the ortho position relative to the amine group may comprise OH, SH or NH ₂ .

The polyamic acid and the polyimide can be prepared according to a general method.

For example, the polyamic acid may be prepared by reacting an aromatic diamine including an OH, SH, or NH 2 group in an ortho position with an amine group and tetracarboxylic anhydride, wherein the polyimide imidizes the polyamic acid. For example by thermal solution imidization or chemical imidization.

For example, the thermal solution imidization further adds benzenes such as benzene, toluene, xylene, cresol, and aliphatic organic solvents such as hexane and cyclohexane to an organic solvent such as N-methylpyrrolidone (NMP). It can be made using an azeotrope.

The polyamic acid and the polyimide are thermally converted by a predetermined heat treatment to be converted into a polymer such as polybenzoxazole, polybenzothiazole, polypyrrolone having picopores and excellent mechanical strength and high free volume. Can be.

Specifically, with respect to the total amount of the repeating units included in the polyamic acid or the polyimide, the ratio (heat conversion rate) of the repeating units to be thermally converted may be about 10 mol% to about 100 mol%. In this case, the heat resistance and mechanical strength of the porous support can be effectively improved, and the wettability with respect to the cation exchange resin can be improved, and the compatibility of the porous support with the cation exchange resin can be effectively improved. In addition, it is possible to prevent delamination between the porous support and the cation exchange resin, and to effectively improve the durability of the polymer electrolyte membrane for a fuel cell including the porous support. Specifically, with respect to the total amount of the repeating units included in the polyamic acid or the polyimide, the ratio (heat conversion rate) of the repeating units to be thermally converted may be about 40 mol% to about 100 mol%.

The polymer derived from the polyamic acid and the polymer derived from the polyimide may have a free volume (FFV) of about 0.18 to about 0.40, and the d-spacing by XRD is about 550 pm to about It can be in the range of 800 pm. Thus, the polymer derived from the polyamic acid and the polymer derived from the polyimide can easily permeate or separate low molecules.

The polymer derived from the polyamic acid and the polymer derived from the polyimide may include picopores, and two or more picopores may be connected to each other to form an hourglass shape. As a result, the polymer may have high porosity, so that low molecules may be efficiently permeated or selectively separated.

In addition, the average diameter of the picopores may be about 600 pm to about 800 pm, but is not limited thereto. The picopores may have a full width at half maximum (FWHM) of about 10 pm to about 40 pm by positron annihilation lifetime spectroscopy (PALS) measurement. This indicates that the size of the generated picopores is fairly uniform. The PALS data is obtained by irradiating positrons generated from 22Na isotopes with the time difference between γ ₀ of 1.27MeV and γ ₁ and γ ₂ of 0.511MeV generated at extinction τ ₁ , τ ₂ , τ _3, etc. Can be obtained using

The porous support 244 may uniformly include micropores and picopores as a whole, and may have a porosity of about 10% by volume to about 95% by volume with respect to the total volume of the support, and may include a cation exchange resin in the pores. As a result, the cationic conductivity, such as hydrogen ion conductivity, can be improved to effectively improve the efficiency of the fuel cell.

The porous support 244 may be formed through electrospinning, and by controlling the method or process conditions of the electrospinning, so that the fiber containing the polymer having the picopores is randomly arranged in the porous support 244. Can be formed.

On the other hand, when forming the porous support 244, by adjusting the method or the process conditions of the electrospinning, the fiber containing the polymer having the picopores may be formed to be arranged in one direction on the porous support 244. have. In this case, the strength in the direction in which the fibers are arranged can be effectively improved. In addition, in the polymer electrolyte membrane for a fuel cell including the porous support 244, the hydrogen ions may be rapidly transferred along the direction in which the fibers are arranged, thereby effectively improving the hydrogen ion conductivity.

The porous support 244 may be formed to have a thickness of about 10 ㎛ to about 200 ㎛. When the thickness of the porous support 244 is within the above range, the mechanical properties, chemical resistance and dimensional stability of the polymer electrolyte membrane 24 including the same may be improved. Specifically, the porous support 244 may be formed to have a thickness of about 20 ㎛ to about 180 ㎛.

In addition, the fuel cell polymer electrolyte membrane 24 includes a cation exchange resin 242, thereby improving cation conductivity, such as hydrogen ion conductivity, and suppressing fuel crossover.

The cation exchange resin 242 is present inside, on the surface, or inside and the surface of the porous support 244. When the cation exchange resin is present in the porous support, it may be present in the micropores and picopores of the porous support.

Thereby, the polymer electrolyte membrane 24 for fuel cells excellent in mechanical strength and dimensional stability and also excellent in cation conductivity, such as hydrogen ion conductivity, can be provided.

The cation exchange resin can improve the cation conductivity, such as hydrogen ion conductivity, of the polymer electrolyte membrane 24 for fuel cells, and can improve the efficiency of the fuel cell.

The cation exchange resin is a polymer containing a cation exchange group selected from the group consisting of sulfonic acid groups, carboxylic acid groups, phosphoric acid groups, phosphonic acid groups, and derivatives thereof. For example, fluorine-based polymers, benzimidazole-based polymers, and polyimides Type polymer, polyetherimide type polymer, polyphenylene sulfide type polymer, polysulfone type polymer, polyether sulfone type polymer, polyether ketone type polymer, polyether-etherketone type polymer, polyphenylquinoxaline type polymer or these Combinations, but are not limited thereto.

The cation exchange resin may include a polymer having a functional group selected from the group consisting of sulfonic acid groups, carboxylic acid groups, phosphoric acid groups, phosphonic acid groups, and derivatives thereof in the polymer. In addition, the cation exchange resin may include a polymer in which the functional group is substituted with a polymer which does not have the functional group as described above, and an acid having the functional group as described above in the polymer which does not have the functional group as described above. It may also comprise a doped polymer.

Examples of the polymer having a functional group selected from the group consisting of sulfonic acid groups, carboxylic acid groups, phosphoric acid groups, phosphonic acid groups and derivatives thereof in the original polymer include Nafion (Nafion, Dupont), sulfonated poly (phenylene Sulfonated-poly (phenylene sulfide sulfone nitrile (s-PSSN)), sulfonated poly (arylene ether sulfone: s-PAES), sulfonated poly (Ether ether ketone) (sulfonated-poly (ether ether ketone: s-PEEK)) and the like, but is not limited thereto.

Examples of polymers capable of forming a cation exchange resin by substituting a functional group selected from the group consisting of a sulfonic acid group, a carboxylic acid group, a phosphoric acid group, a phosphonic acid group and derivatives thereof, or by doping an acid having the functional group as described above. The polybenzimidazole, polyimide, polyphenylene sulfide, polysulfone, polysulfone derivative, polyphenylene oxide, polyphenylene sulfide, polyphosphazene and the like, but is not limited thereto.

The polymer electrolyte membrane 24 for the fuel cell may include the porous support and the cation exchange resin in a weight ratio of about 99: 1 to about 10:90. When the content ratio of the porous support and the cation exchange resin is within the above range, the polymer electrolyte membrane for a fuel cell including the same may have excellent mechanical strength and dimensional stability. Specifically, the porous support and the cation exchange resin may be included in a weight ratio of about 95: 5 to about 30:70.

Although not shown in FIG. 1, a polymer electrolyte for a fuel cell, which is located between the anode 22 and the cathode 26, includes a porous support 244 but does not include a separate cation exchange resin 242. Membrane 24 may be used. In this case, the fuel cell polymer electrolyte membrane 24 is formed by doping with acid on the inside, the surface, or the inside and the surface thereof. The acid may be selected from the group consisting of sulfonic acid, carboxylic acid, phosphoric acid, phosphonic acid, and derivatives thereof, but is not limited thereto. The acid doped into the porous support 244 plays a role similar to that of the cation exchange resin 242. Accordingly, the acid doped in the porous support 244 may improve the cation conductivity, for example, the hydrogen ion conductivity of the polymer electrolyte membrane 24 for the fuel cell, and may improve the efficiency of the fuel cell.

The polymer electrolyte membrane 24 for the fuel cell may have a thickness of about 20 μm to about 300 μm. When the thickness of the polymer electrolyte membrane 24 for fuel cells is within the above range, excellent cation conductivity, such as hydrogen ion conductivity, can be achieved, fuel crossover can be suppressed, and also excellent mechanical strength, dimensional stability, heat resistance and resistance to heat. Chemicality can be effectively achieved. Specifically, the fuel cell polymer electrolyte membrane 24 may have a thickness of about 20 μm to about 250 μm.

Hereinafter, the polymer forming the porous support will be described in detail.

The polyamic acid used to form the porous support may be a polyamic acid including a repeating unit represented by the following Chemical Formulas 1 to 4, a polyamic acid copolymer comprising a repeating unit represented by the following Chemical Formulas 5 to 8, a copolymer thereof, and It can be selected from the group consisting of these blends.

[Formula 1]

[Formula 2]

(3)

[Formula 4]

[Chemical Formula 5]

[Formula 6]

[Formula 7]

[Formula 8]

In Chemical Formulas 1 to 8,

Ar ₁ is an aromatic ring group selected from a substituted or unsubstituted tetravalent C6 to C24 arylene group and a substituted or unsubstituted tetravalent C4 to C24 heterocyclic group, wherein the aromatic ring group is present alone; Two or more are joined to each other to form a condensed ring; Two or more single bonds, O, S, C (= 0), CH (OH), S (= 0) ₂ , Si (CH ₃ ) ₂ , (CH ₂ ) _p (where 1 ≦ _p ≦ 10) , (CF ₂ ) _q (where 1 ≦ _q ≦ 10), C (CH ₃ ) ₂ , C (CF ₃ ) ₂ or C (═O) NH, and

Ar ₂ is an aromatic ring group selected from a substituted or unsubstituted divalent C6 to C24 arylene group and a substituted or unsubstituted divalent C4 to C24 heterocyclic group, wherein the aromatic ring group is present alone; Two or more are joined to each other to form a condensed ring; Two or more single bonds, O, S, C (= 0), CH (OH), S (= 0) ₂ , Si (CH ₃ ) ₂ , (CH ₂ ) _p (where 1 ≦ _p ≦ 10) , (CF ₂ ) _q (where 1 ≦ _q ≦ 10), C (CH ₃ ) ₂ , C (CF ₃ ) ₂ or C (═O) NH, and

Q is O, S, C (= O), CH (OH), S (= O) ₂ , Si (CH ₃ ) ₂ , (CH ₂ ) _p (where 1 ≦ _p ≦ 10), (CF ₂ ) _q (where 1 ≦ _q ≦ 10), C (CH ₃ ) ₂ , C (CF ₃ ) ₂ , C (═O) NH, C (CH ₃ ) (CF ₃ ), or a substituted or unsubstituted phenylene group Wherein the substituted phenylene group is substituted with a C1 to C6 alkyl group or a C1 to C6 haloalkyl group, wherein Q is linked to both aromatic rings in the mm, mp, pm, or pp position,

Y is the same or different at each repeating unit, each independently OH, SH or NH ₂ ,

n is an integer satisfying 20 ≦ n ≦ 200,

m is an integer satisfying 10≤m≤400,

l is an integer satisfying 10 ≦ l ≦ 400.

Examples of the copolymer of the polyamic acid including the repeating units represented by Formulas 1 to 4 include polyamic acid copolymers including the repeating units represented by the following Formulas 9 to 18.

[Formula 9]

[Formula 10]

[Formula 11]

[Chemical Formula 12]

[Formula 13]

[Formula 14]

[Formula 15]

[Formula 16]

[Formula 17]

[Formula 18]

In Chemical Formulas 9 to 18,

Ar ₁ , Q, n, m and l are the same as defined in Formula 1 to Formula 8,

Y and Y 'are different from each other, and are each independently OH, SH or NH ₂ .

The polyimide used to form the porous support may be a polyimide comprising a repeating unit represented by the following Formulas 19 to 22, a polyimide copolymer comprising a repeating unit represented by the following Formulas 23 to 26, a copolymer thereof, and It may be selected from the group consisting of blends, but is not limited thereto.

[Formula 19]

[Formula 20]

[Formula 21]

[Formula 22]

(23)

[Formula 24]

[Formula 25]

[Formula 26]

In Chemical Formulas 19 to 26,

Ar ₁ , Ar ₂ , Q, Y, n, m and l are the same as defined in Chemical Formulas 1 to 8.

As an example of the copolymer of the polyimide containing the repeating unit represented by the said Formula 19-22, the polyimide copolymer containing the repeating unit represented by following Formula 27-36 is mentioned.

[Formula 27]

[Formula 28]

[Formula 29]

[Formula 30]

[Formula 31]

[Formula 32]

[Formula 33]

[Formula 34]

[Formula 35]

[Formula 36]

In Chemical Formulas 27 to 36,

Ar ₁ , Q, m and l are as defined in the formula 1 to 8,

Y and Y 'are the same or different from each other and are each independently OH, SH or NH ₂ .

In Formulas 1 to 36, an example of Ar ₁ may be selected from those represented by the following formulas, but is not limited thereto.

Where

X ₁ , X ₂ , X ₃ and X ₄ are the same or different from each other and each independently O, S, C (= 0), CH (OH), S (= 0) ₂ , Si (CH ₃ ) ₂ , ( CH ₂ ) _p (where 1 ≦ _p ≦ 10), (CF ₂ ) _q (where 1 ≦ _q ≦ 10), C (CH ₃ ) ₂ , C (CF ₃ ) ₂ , or C (═O) NH ego,

W ₁ and W ₂ are the same or different and are each independently O, S, or C (═O),

Z ₁ is O, S, CR ₁₀₀ R ₁₀₁ or NR ₁₀₂ , wherein R ₁₀₀ , R ₁₀₁ and R ₁₀₂ are the same or different from each other and are each independently hydrogen or a C1 to C5 alkyl group,

Z ₂ and Z ₃ are the same or different from each other and independently of each other N or CR ₁₀₃ (wherein R ₁₀₃ is hydrogen or a C1 to C5 alkyl group) but not CR ₁₀₃ at the same time,

R ₁ to R ₄₂ are the same or different and are each independently hydrogen or a substituted or unsubstituted C1 to C10 aliphatic organic group,

k1 to k3, k8 to k14, k24 and k25 are integers of 0 to 2,

k5, k15, k16, k19, k21 and k23 are integers of 0 or 1,

k4, k6, k7, k17, k18, k20, k22, k26 to k29, k31, k34 to k36, k38, k39 and k42 are integers from 0 to 3,

k30, k37, k40 and k41 are integers from 0 to 4,

k32 and k33 are integers of 0-5.

In Formulas 1 to 36, a specific example of Ar ₁ may be selected from those represented by the following formulas, but is not limited thereto.

In Formulas 1 to 36, Ar ₂ may be selected from those represented by the following formulas, but is not limited thereto.

Where

X ₁ , X ₂ , X ₃ and X ₄ are the same or different from each other and each independently O, S, C (= 0), CH (OH), S (= 0) ₂ , Si (CH ₃ ) ₂ , ( CH ₂ ) _p (where 1 ≦ _p ≦ 10), (CF ₂ ) _q (where 1 ≦ _q ≦ 10), C (CH ₃ ) ₂ , C (CF ₃ ) ₂ , or C (═O) NH ego,

W ₁ and W ₂ are the same or different and are each independently O, S, or C (═O),

Z ₁ is O, S, CR ₁₀₀ R ₁₀₁ or NR ₁₀₂ , wherein R ₁₀₀ , R ₁₀₁ and R ₁₀₂ are the same or different from each other and are each independently hydrogen or a C1 to C5 alkyl group,

Z ₂ and Z ₃ are the same or different from each other and independently of each other N or CR ₁₀₃ (wherein R ₁₀₃ is hydrogen or a C1 to C5 alkyl group) but not CR ₁₀₃ at the same time,

R ₄₃ to R ₈₉ are the same or different from each other and are each independently hydrogen, a substituted or unsubstituted C1 to C10 aliphatic organic group, or a metal sulfonate group,

k43, k49, k64 to k68, k72 to k76, and k82 to k89 are integers of 0 to 4,

k44 to k46, k48, k51, k54, k55, k57, k58, k61 and k63 are integers from 0 to 3,

k47, k52, k53, k56, k59, k60, k62, k70, k78, k80 and k81 are integers from 0 to 2,

k50 is an integer of 0 or 1,

k69, k71, k77 and k79 are integers of 0-5.

In Chemical Formulas 1 to 36, specific examples of Ar ₂ may be selected from those represented by the following formulas, but are not limited thereto.

Wherein M is a metal, and the metal may be sodium, potassium, lithium, alloys thereof, or a combination thereof, but is not limited thereto.

In Formulas 1 to 36, examples of Q may be selected from C (CH ₃ ) ₂ , C (CF ₃ ) ₂ , O, S, S (= 0) ₂ or C (= 0), but are not limited thereto. It is not.

In Formulas 1 to 36, Ar ₁ may be a functional group represented by any one of Formulas A1 to A8, Ar ₂ may be a functional group represented by any one of Formulas B1 to B11, and Q is C (CF ₃ ) _It may be ₂ , but is not limited thereto.

[Formula A1] [Formula A2] [Formula A3]

[Formula A4] [Formula A5] [Formula A6]

                  Formula A7 Formula A8

[Formula B1] [Formula B2] [Formula B3]

[Formula B4] [Formula B5] [Formula B6] [Formula B7]

Formula B8 Formula B9

[Formula B10] [Formula B11]

The polyamic acid including the repeating unit represented by Formula 1 to Formula 4 and the polyimide including the repeating unit represented by Formula 19 to Formula 22 may be prepared through a general manufacturing method. For example, the monomer is prepared by reacting tetracarboxylic anhydride with an aromatic diamine including OH, SH, or NH ₂ groups.

The polyamic acid including the repeating unit represented by Formula 1 to Formula 4 is imidized and thermally converted by a predetermined heat treatment, and the polyimide including the repeating unit represented by Formula 19 to Formula 22 is subjected to a predetermined heat treatment. By heat conversion to polymers such as polybenzoxazoles, polybenzothiazoles, polypyrrolones, which have picopores and have excellent mechanical properties and high free volume. Wherein polyhydroxyamic acid wherein Y is OH in Formulas 1 to 4 or polybenzoimazole derived from polyhydroxyimide where Y is OH in Formulas 19 to 22, polythiolamic acid where Y is SH, or Porous supports are prepared comprising polybenzothiazoles derived from polythiolimides, polyaminoamic acids where Y is NH ₂ or polypyrrolones derived from polyaminoimide.

In addition, the molar ratio between each repeating unit in the copolymer of the polyamic acid containing a repeating unit represented by Formula 1 to Formula 4; Alternatively, by controlling the molar ratio between the repeating units in the copolymer of the polyimide including the repeating units represented by Formulas 19 to 22, it is possible to control the physical properties of the prepared porous support.

The polyamic acid copolymer including the repeating unit represented by Formula 5 to Formula 8 may be imidized and thermally converted by a predetermined heat treatment. In addition, the polyimide copolymer including the repeating unit represented by Formula 23 to Formula 26 may be thermally converted by a predetermined heat treatment. As a result, the polyamic acid copolymer including the repeating unit represented by Formula 5 to Formula 8 and the polyimide copolymer including the repeating unit represented by Formula 23 to Formula 26 have picopores and have excellent mechanical properties and high freedom. Converted into volumetric poly (benzoxazole-imide) copolymers, poly (benzothiazole-imide) copolymers or poly (pyrrolone-imide) copolymers, using these copolymers It can form a porous support comprising a. At this time, by controlling the copolymerization ratio (molar ratio) between the block which is converted to polybenzoxazole, polybenzothiazole or polypyrrolone and the block made of polyimide by intramolecular and intermolecular rearrangement, it is possible to control the physical properties of the prepared porous support. Do.

The copolymer of the polyamic acid including the repeating unit represented by Formula 9 to Formula 18 may be imidized and thermally converted by a predetermined heat treatment. In addition, the copolymer of the polyimide including the repeating unit represented by the formula (27) to (36) may be thermally converted by a predetermined heat treatment. As a result, the copolymer of the polyamic acid including the repeating unit represented by the formula (9) to the formula (18) and the copolymer of the polyimide including the repeating unit represented by the formula (27) to (36) has picopores and has excellent mechanical properties and It is converted into a copolymer of polybenzoxazole, polybenzothiazole and polypyrrolone having a high degree of free volume, which can be used to form a porous support comprising such a copolymer. At this time, by controlling the copolymerization ratio (molar ratio) between the blocks that are thermally converted to polybenzoxazole, polybenzothiazole and polypyrrolone, it is possible to control the physical properties of the prepared porous support.

Molar ratio between each repeating unit in the copolymer of polyamic acid including the repeating unit represented by Formula 1 to Formula 4; Or the inter-block copolymerization ratio (molar ratio) m: l of the polyamic acid copolymer including the repeating unit represented by Formulas 5 to 8 is about 0.1: 9.9 to about 9.9: 0.1, specifically about 2: 8 to about 8: 2, more specifically about 5: 5.

In addition, the molar ratio between each repeating unit in the copolymer of the polyimide containing the repeating unit represented by the formula (19) to formula (22); Or the inter-block copolymerization ratio (molar ratio) m: l of the polyimide copolymer including the repeating units represented by Formulas 23 to 26 may be about 0.1: 9.9 to about 9.9: 0.1, specifically about 2: 8 to about 8: 2, more specifically about 5: 5.

This molar ratio to copolymer ratio affects the morphology of the porous support to be produced, which is related to pore properties, heat resistance, surface hardness, and the like. When the molar ratio to the copolymerization ratio is within the above range, the porous support to be prepared may have excellent mechanical properties and dimensional stability, may have excellent porosity, and also have excellent processability to reduce the process time and cost reduction effect. .

In the porous support, the polymer derived from the polyamic acid and the polymer derived from the polyimide may include a polymer including a repeating unit represented by any one of Formulas 37 to 50 or a copolymer thereof, but is not limited thereto. It doesn't happen.

[Formula 37]

[Formula 38]

[Formula 39]

[Formula 40]

[Formula 41]

[Formula 42]

[Formula 43]

[Formula 44]

[Formula 45]

[Formula 46]

[Formula 47]

[Formula 48]

[Formula 49]

[Formula 50]

In Chemical Formulas 37 to 50,

_{Ar 1, Ar 2, Q,} n, m and l are the same as described in each of Ar _1, in the above Chemical Formulas 1 to _{8 Ar 2, Q, n,} m and l,

Ar ₁ ′ is an aromatic ring group selected from a substituted or unsubstituted divalent C6 to C24 arylene group and a substituted or unsubstituted divalent C4 to C24 heterocyclic group, wherein the aromatic ring group is present alone; Two or more are joined to each other to form a condensed ring; Two or more single bonds, O, S, C (= 0), CH (OH), S (= 0) ₂ , Si (CH ₃ ) ₂ , (CH ₂ ) _p (where 1 ≦ _p ≦ 10) , (CF ₂ ) _q (where 1 ≦ _q ≦ 10), C (CH ₃ ) ₂ , C (CF ₃ ) ₂ or C (═O) NH, and

Y '' is O or S.

In the general formula 37 to 50, Ar _1, for example, and specific examples of Ar ₂ and Q are the same as each of the above Chemical Formulas 1 to 36 in the Ar _1, Ar _2, and examples of Q and mentioned specific examples.

In addition, in Chemical Formulas 37 to 50, examples and specific examples of Ar _{1 ′} are the same as those mentioned for Examples and specific examples of Ar ₂ of Chemical Formulas 1 to 36.

In Formulas 37 to 50, Ar ₁ may be a functional group represented by any one of Formulas A1 to A8, Ar ₁ ′ may be a functional group represented by any one of Formulas C1 to C8, and Ar ₂ may be represented by Formula B1 It may be a functional group represented by any one of to B11, Q may be C (CF ₃ ) ₂ , but is not limited thereto.

[Formula C1] [Formula C2] [Formula C3]

[Formula C4] [Formula C5] [Formula C6]

Formula C7 Formula C8

On the other hand, in the fuel cell polymer electrolyte membrane, the porous support may be a surface containing a fluorine group. In this case, the adhesion with the ion conductor can be improved, and the wettability, permeation, electrical conductivity, grafting characteristics and mechanical behavior of the porous support can be improved. It can be improved.

The fluorine group may be introduced by, for example, direct fluorination or plasma deposition using fluorine or fluoride, but is not limited thereto.

The porous support has excellent dimensional stability with shrinkage of less than about 10% even after heat treatment.

According to another embodiment of the present invention, a polyamic acid or polyimide having a repeating unit prepared from an aromatic diamine and a dianhydride including at least one functional group present at an ortho position relative to an amine group; And it provides a composition for forming a porous support comprising an organic solvent. The organic solvent is dimethyl sulfoxide; N-methyl-2-pyrrolidone; N-methylpyrrolidone; N, N-dimethylformamide; N, N-dimethylacetamide; ketones selected from the group consisting of γ-butyrolactone, cyclohexanone, 3-hexanone, 3-heptanone, and 3-octanone; And it is selected from the group consisting of a combination thereof.

Using the organic solvent can easily dissolve a polymer such as the polyamic acid or the polyimide. In addition, by mixing well with the adjuvant to be described later, the composition for forming the porous support may be formed in a meta-stable state, and thus the porous support may be easily formed.

The composition for forming a porous support may include about 1% to about 40% by weight of the polyamic acid or the polyimide and about 60% to about 99% by weight of the organic solvent, based on the total amount of the composition for forming a porous support. Can be. When the content of each component of the composition for forming a porous support is within the above range, the viscosity of the composition for forming a porous support may be properly maintained to facilitate the preparation of the porous support, and the size of the surface and internal pores of the formed porous support may be adjusted. It can be adjusted appropriately. In addition, the strength of the porous support can be maintained excellent, thereby easily forming a porous support having excellent mechanical strength and dimensional stability and a polymer electrolyte membrane for a fuel cell including the same.

The composition for forming the porous support is water; Alcohols selected from the group consisting of methanol, ethanol, 2-methyl-1-butanol, 2-methyl-2-butanol, glycerol, ethylene glycol, diethylene glycol and propylene glycol; Ketones selected from the group consisting of acetone and methylethyl ketone; A polymer compound selected from the group consisting of polyvinyl alcohol, polyacrylic acid, polyacrylamide, polyethylene glycol, polypropylene glycol, chitosan, chitin, dextran and polyvinylpyrrolidone; Tetrahydrofuran; Trichloroethane; And it may further comprise an adjuvant selected from the group consisting of a combination thereof.

The adjuvant may not be used alone because it is not excellent in solubility with polyamic acid or polyimide, but when properly mixed with an organic solvent, a composition for forming a meta-stable porous support may be prepared. When electrospinning, it is possible to effectively form a nonwoven fabric having an appropriate pore size, pore distribution and porosity.

The adjuvant may be removed by diffusion, evaporation, etc. when forming the porous support, to form micropores in the porous support, thereby increasing the porosity of the porous support. Specifically, the polymer compound can be used as a pore control agent. In addition, the adjuvant may be used for controlling the viscosity of the composition for forming a phase separation temperature or the porous support.

The composition for forming a porous support is about 1% to about 40% by weight of the polyamic acid or polyimide and about 10% to about 95% by weight of the organic solvent based on the total amount of the composition for forming a porous support including the auxiliary agent. Wt%, and from about 4 wt% to about 70 wt% of the adjuvant. When the content of each component of the composition for forming a porous support is within the above range, the viscosity of the composition for forming a porous support may be properly maintained to facilitate the preparation of the porous support, and the size of the surface and internal pores of the formed porous support may be adjusted. It can be adjusted appropriately. In addition, the strength of the porous support can be maintained excellent, thereby easily forming a porous support having excellent mechanical strength and dimensional stability and a polymer electrolyte membrane for a fuel cell including the same.

 The composition for forming the porous support may have a viscosity of about 0.01 Pa · s to about 100 Pa · s. When the viscosity of the composition for forming a porous support is within the above range, the composition for forming a porous support can be easily electrospun, and the porous support can be easily solidified through a phase transition phenomenon.

In the composition for forming the porous support, the polyamic acid and the polyimide may each have a weight average molecular weight (Mw) of about 10,000 g / mol to about 500,000 g / mol. When the weight average molecular weight of the polyamic acid and the polyimide is within the above range, the synthesis thereof is easy, and the viscosity of the composition for forming a porous support including the same is appropriately maintained so that the processability is excellent, and the polymer and the poly are derived from the polyamic acid. Polymers derived from meads can be maintained with good mechanical strength and dimensional stability.

In the composition for forming a porous support, the polyamic acid is a polyamic acid comprising a repeating unit represented by Formulas 1 to 4, a polyamic acid copolymer comprising a repeating unit represented by Formulas 5 to 8, copolymers thereof And blends thereof. In addition, the polyimide is a polyimide comprising a repeating unit represented by the formula (19) to 22, a polyimide copolymer containing a repeating unit represented by the formula (23 to 26), a group thereof and blends thereof Can be selected from.

According to another embodiment of the present invention, forming a nonwoven fabric by electrospinning the composition for forming the porous support; And heat treating the nonwoven fabric to form a porous support including a polymer derived from a polyamic acid or a polymer derived from polyimide.

According to another embodiment of the present invention, forming a nonwoven fabric by electrospinning the composition for forming the porous support; Heat treating the nonwoven fabric to form a porous support comprising a polymer derived from polyamic acid or a polymer derived from polyimide; And it provides a method for producing a polymer electrolyte membrane for a fuel cell comprising the step of forming a cation exchange resin on the inside, surface, or the inside and the surface of the porous support.

By electrospinning the composition for forming the porous support, it is possible to form a nonwoven fabric comprising a fiber having a diameter of several nm to several tens of micrometers. Nonwovens comprising such fibers can have a large specific surface area and can have significant surface roughness. In addition, the nonwoven fabric formed at this time includes micropores.

The nonwoven fabric may be formed by randomly arranging fibers including the composition for forming the porous support by controlling the method and process conditions of the electrospinning process.

On the other hand, the non-woven fabric may be formed by adjusting the method and process conditions of the electrospinning, the fiber comprising a composition for forming a porous support is arranged in one direction. The advantages are as described above.

The electrospinning may be performed by applying a high voltage of about 1 kV to about 1,000 kV. Since electrospinning may be performed according to a general method, details thereof will be omitted.

Subsequently, the nonwoven fabric is heat treated. The polyamic acid or polyimide included in the nonwoven fabric by the heat treatment is excellent in mechanical strength and dimensional stability by thermal conversion and has a high free volume polymer such as polybenzoxazole, polybenzothiazole, polypyrrolone Converted to a polymer. As a result, a porous support having excellent physical properties such as mechanical strength and dimensional stability can be formed.

Specifically, with respect to the total amount of the repeating units included in the polyamic acid or the polyimide, the ratio (heat conversion rate) of the repeating units to be thermally converted may be about 10 mol% to about 100 mol%, specifically about 40 Mole% to about 100 mole%. Advantages that the thermal conversion rate may be in the above range is as described above.

The heat treatment may be performed at a temperature of about 250 ℃ to about 550 ℃, may be carried out for about 10 minutes to about 5 hours, the temperature increase rate during the heat treatment may be about 1 ℃ / min to about 20 ℃ / min. When the heat treatment is performed under the above conditions, thermal conversion of the polyamic acid and the polyimide can be effectively performed. That is, the polyamic acid and the polyimide are easily converted into polymers such as polybenzoxazole, polybenzothiazole, and polypyrrolone having picopores and excellent mechanical properties and high free volume, thereby providing mechanical properties and dimensional stability. It is excellent in chemical resistance and heat resistance, and can effectively contain a cation exchange resin and form a porous support. Specifically, the heat treatment may be performed at a temperature of about 350 ℃ to about 450 ℃, may be performed for about 1 hour to about 3 hours, the temperature increase rate during the heat treatment is from about 5 ℃ / min to about 10 ℃ / minute Can be.

Subsequently, a cation exchange resin is formed on the inside, the surface, or the inside and the surface of the porous support. The method of forming a cation exchange resin on the inside, the surface, or the inside and the surface of the porous support has a functional group selected from the group consisting of sulfonic acid groups, carboxylic acid groups, phosphoric acid groups, phosphonic acid groups and derivatives thereof in the polymer. Dipping the porous support in a solution containing a polymer; And immersing the porous support in a solution containing a polymer that does not have the functional group, and drying it, and then immersing it again in an aqueous acid solution containing the functional group to substitute the functional group as described above or And a method of doping with an acid having a functional group, but is not limited thereto.

The solution containing the polymer for forming the cation exchange resin is a polymer such as N, N-dimethylacetamide (N, N-dimethylacetamide, DMAc), N-methylpyrrolidone (N-Methyl pyrrolidone, NMP) It can be prepared by dissolving in an organic solvent. Specifically, the solution containing the polymer may be prepared by dissolving in an organic solvent such as N, N-dimethylacetamide, N-methylpyrrolidone, and the like so that the polymer is about 1% by weight to about 40% by weight.

After the porous support is immersed in a solution containing the prepared polymer at a temperature of room temperature to about 200 ° C., specifically about 80 ° C. to about 200 ° C., the mixture is left for about 1 hour to about 20 hours.

For example, when the porous support is immersed in a solution containing a polymer having a functional group selected from the group consisting of sulfonic acid group, carboxylic acid group, phosphoric acid group, phosphonic acid group and derivatives thereof in the polymer, By drying in an oven, a polymer electrolyte membrane for a fuel cell can be formed. However, the present invention is not limited thereto, and the polymer electrolyte membrane for a fuel cell may be formed by immersion and drying again in an acid aqueous solution having a functional group selected from the group consisting of sulfonic acid groups, carboxylic acid groups, phosphoric acid groups, phosphonic acid groups, and derivatives thereof after the drying. have.

When the porous support is immersed in a solution containing a polymer which does not have a functional group selected from the group consisting of sulfonic acid groups, carboxylic acid groups, phosphoric acid groups, phosphonic acid groups and derivatives thereof in the polymer, it is dried in a vacuum oven. And then immersed in an aqueous solution containing an acid selected from the group consisting of sulfonic acid, carboxylic acid, phosphoric acid, phosphonic acid and derivatives thereof, and then taken out, washed and dried with distilled water (deionized water) for fuel cells. A polymer electrolyte membrane can be formed.

According to another embodiment of the present invention, forming a nonwoven fabric by electrospinning the composition for forming the porous support; Heat treating the nonwoven fabric to form a porous support comprising a polymer derived from the polyimide; And it provides a method for producing a polymer electrolyte membrane for a fuel cell comprising the step of doping the acid on the inside, the surface, or the inside and the surface of the porous support.

The acid may be selected from the group consisting of sulfonic acid, carboxylic acid, phosphoric acid, phosphonic acid, and derivatives thereof, but is not limited thereto.

In this case, a polymer electrolyte membrane for a fuel cell is formed by directly doping an acid into the inside, the surface, or the inside and the surface of the porous support without forming a separate cation exchange resin inside, the surface, or the inside and the surface of the porous support. That's how.

Specifically, the porous support is immersed in an aqueous solution containing an acid selected from the group consisting of sulfonic acid, carboxylic acid, phosphoric acid, phosphonic acid, and derivatives thereof, while maintaining about 25 ° C to about 200 ° C, about 1 After being left for about 24 hours to dry, the polymer electrolyte membrane for a fuel cell can be formed by drying. As the acid aqueous solution, an acid aqueous solution having a concentration of about 1 M to about 30 M may be used. The description of the electrospinning and heat treatment is as described above.

In addition, according to another embodiment of the present invention, forming a nonwoven fabric by electrospinning the composition for forming the porous support; Heat treating the nonwoven fabric to form a porous support comprising a polymer derived from polyamic acid or a polymer derived from polyimide; And it provides a method for producing a polymer electrolyte membrane for a fuel cell comprising the step of introducing a fluorine group on the surface of the porous support. In this case, the adhesion between the porous support and the cation exchange resin, for example, can be improved, and the wettability of the porous support to the cation exchange resin can be improved. In addition, permeation, electrical conductivity, grafting characteristics, and mechanical behavior of the polymer electrolyte membrane for a fuel cell including the porous support may be improved. For example, the fluorine group may be introduced into the porous support by using fluorine or fluoride, for example, by direct fluorination or plasma deposition, thereby producing a surface fluorinated porous support.

Subsequently, as described above, the porous support may be impregnated with a cation exchange resin to prepare a polymer electrolyte membrane for a fuel cell.

The description of the electrospinning and heat treatment is as described above.

2 shows a schematic structure of a fuel cell system according to an embodiment of the present invention. Referring to FIG. 2, a system for supplying a fuel and an oxidant to an electric generator using a pump is illustrated, but the present invention is not limited thereto, and may be used in a fuel cell system structure using a diffusion method without using a pump. .

The fuel cell system 1 according to an embodiment of the present invention includes at least one electric generator 3 for generating electrical energy through an oxidation reaction of a fuel and a reduction reaction of an oxidant, and a fuel to the electricity generator 3. And an oxidant supply unit 7 for supplying an oxidant to the electricity generation unit 3.

The fuel supply unit 5 for supplying the fuel may include a fuel tank 9 storing fuel and a fuel pump 11 connected to the fuel tank 9. The fuel pump 11 functions to discharge fuel stored in the fuel tank 9 by a predetermined pumping force.

The oxidant supply unit 7 for supplying the oxidant to the electricity generating unit 3 includes at least one oxidant pump 13 for sucking the oxidant with a predetermined pumping force.

The electricity generating unit 3 is composed of a membrane-electrode assembly 17 for oxidizing and reducing a fuel and an oxidant, and separators 19 and 19 'for supplying fuel and an oxidant to both sides of the membrane-electrode assembly. At least one of these electricity generating units 17 constitutes a stack 15.

Example

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the following Examples and Comparative Examples are for illustrative purposes only and are not intended to limit the present invention.

Example  1: Preparation of Polymer Electrolyte Membrane for Fuel Cell

A polymer electrolyte membrane for a fuel cell including a polymer comprising a polybenzoxazole comprising a repeating unit represented by the following Formula 51 was prepared from polyhydroxyimide as represented by Scheme 1 below.

Scheme 1

(1) Preparation of Polyhydroxyimide

3.66 g (10 mmol) of 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane and 4.44 g (10 mmol) of 4,4 '-(hexafluoroisopropylidene) diphthalic anhydride ) Was added to 32.4 g of N-methylpyrrolidone (NMP) and stirred vigorously for 4 hours. Then, polyhydroxyimide was prepared by adding 32 ml of xylene as an azeotrope and removing the mixture of water and xylene while thermal solution imidization at 180 ° C. for 12 hours.

(2) Preparation of Porous Support Containing Polybenzoxazole

Dimethylformamide (DMF) was added to the prepared solution containing polyhydroxyimide, thereby preparing a composition for forming a porous support including 25 wt% of the polyhydroxyimide.

The composition for forming the porous support was supplied with a drum type electrospinning equipment ESR200RD (manufactured by NanoNC), +10 kV to the cylinder part, -4 kV to the drum part, and a radial spacing of 15 cm and a flow rate of 0.1. A nonwoven fabric containing fibers was prepared by electrospinning at a μl / min and a drum speed of 50 rpm.

Subsequently, the nonwoven fabric prepared above was heat-treated at 300 ° C. for 1 hour, and then heat-treated at 400 ° C. for 1 hour, and then slowly cooled to room temperature to prepare a porous support including polybenzoxazole. The temperature increase rate at the time of the said heat processing was 5 degreeC / min.

The porosity of the porous support measured using capillary flow porometer equipment CFP-1500-AE (manufactured by Porous Materials) was 91%. In addition, the thickness of the porous support was 40 μm.

(3) Preparation of Polymer Electrolyte Membrane for Fuel Cell Containing Polybenzoxazole

The porous support was dissolved in 10 g of sulfonated-poly (arylene ether sulfone: s-PAES) in 90 g of N, N-dimethylacetamide (DMAc) in a solution for 1 hour. After immersion, the polymer electrolyte membrane for a fuel cell containing polybenzoxazole was prepared by drying slowly in an oven. The thermal conversion was 46 mol%.

The FT-IR analysis revealed bands of 1,553 cm ^- 1, 1,480 cm ^-1 (C = N) and 1,058 cm ^-1 (CO), which are polybenzoxazole characteristic bands that did not exist in polyhydroxyimide. In addition, the prepared polymer had a free volume of 0.193 and an interplanar distance of 558 pm.

The density of the polymer is related to the free volume.

First, the film density was measured by buoyancy method using a Sartorius LA 310S analytical balance according to Equation 1 below.

[Equation 1]

In the above equation (1)

는 고분자의 밀도이고,

Is the density of the polymer,

는 탈이온수의 밀도이고,

Is the density of deionized water,

는 공기 중에서 측정한 고분자의 무게이고,

Is the weight of the polymer measured in air,

는 탈이온수에서 측정한 고분자의 무게이다.

Is the weight of the polymer measured in deionized water.

Free volume degrees (FFV, V _f ) were calculated according to the following equation (2) from the data.

[Equation 2]

In Equation 2,

V is the specific volume of the polymer,

Vw is the specific Van der Waals volume.

The interplanar distance was calculated according to the Bragg's equation from the X-ray diffraction pattern results.

In addition, in the porous support including the polybenzoxazole, the full width at half maximum (FWHM) by positron annihilation lifetime spectroscopy (PALS) measurement was 16.1 pm.

PALS measurements were performed on nitrogen at ambient temperature using an automated EG & G Ortec fast-fast coincidence spectrometer. The time resolution of the system was 240 Hz.

A polymer membrane was set to 1 ㎜ thickness on either side of the ²² Na-Ti foil source ^{(22 Na-Ti foil source)} . There was no source correction for Ti foil (2.5 μm thick). Each spectrum consisted of approximately 10 million integrated counts and was made up of a sum of three decaying exponentials or a continuous distribution. The PALS data is obtained by investigating positrons generated from ²² Na isotopes. The time difference between γ _{0 of} 1.27MeV generated at generation and γ ₁ , γ ₂ of 0.511MeV generated at extinction τ ₁ , τ ₂ , τ ₃ It could obtain using etc.

The pore size was calculated using Equation 3 below using the extinction time of two γ signals of 0.511 MeV.

&Quot; (3) "

In Equation 3,

τ _{o- Ps} is the extinction time of the positron,

R is the pore size,

ΔR is an experimental parameter on the assumption that the pores are spherical.

Example  2: Preparation of Polymer Electrolyte Membrane for Fuel Cell

A polymer electrolyte membrane for a fuel cell including a polybenzoxazole including a repeating unit represented by Chemical Formula 51 was prepared in the same manner as in Example 1 except that the nonwoven fabric was heat treated at 400 ° C. for 2 hours. The thermal conversion was 61%.

The FT-IR analysis revealed bands of 1,553 cm ^-1 , 1,480 cm ^-1 (C = N) and 1,058 cm ^-1 (CO), which are polybenzoxazole characteristic bands that were not present in polyhydroxyimide. In addition, the prepared polymer had a free volume of 0.200 and an interplanar distance of 564.4 pm.

In addition, the full width at half maximum (FWHM) measured by positron annihilation lifetime spectroscopy (PALS) was 19.4 pm.

Example  3: Preparation of Polymer Electrolyte Membrane for Fuel Cell

A polymer electrolyte membrane for a fuel cell including a polybenzoxazole including a repeating unit represented by Chemical Formula 51 was prepared in the same manner as in Example 1 except that the nonwoven fabric was heat treated at 400 ° C. for 3 hours. Thermal conversion was 69%.

The FT-IR analysis revealed bands of 1,553 cm ^-1 , 1,480 cm ^-1 (C = N) and 1,058 cm ^-1 (CO), which are polybenzoxazole characteristic bands that were not present in polyhydroxyimide. In addition, the prepared polymer had a free volume of 0.204 and an interplanar distance of 567.6 pm.

In addition, the full width at half maximum (FWHM) measured by positron annihilation lifetime spectroscopy (PALS) was 21.1 pm.

Example  4: Preparation of Polymer Electrolyte Membrane for Fuel Cell

A polymer electrolyte membrane for a fuel cell including a polybenzoxazole including a repeating unit represented by Chemical Formula 51 was prepared in the same manner as in Example 1 except that the nonwoven fabric was heat treated at 425 ° C. for 1 hour. The thermal conversion was 80%.

The FT-IR analysis revealed bands of 1,553 cm ^-1 , 1,480 cm ^-1 (C = N) and 1,058 cm ^-1 (CO), which are polybenzoxazole characteristic bands that were not present in polyhydroxyimide. In addition, the prepared polymer had a free volume of 0.210 and an interplanar distance of 572 pm.

In addition, the full width at half maximum (FWHM) measured by positron annihilation lifetime spectroscopy (PALS) was 23.6 pm.

Example  5: Preparation of polymer electrolyte membrane for fuel cell

A polymer electrolyte membrane for a fuel cell including a polybenzoxazole including a repeating unit represented by Chemical Formula 51 was prepared in the same manner as in Example 1 except that the nonwoven fabric was heat treated at 425 ° C. for 2 hours. Thermal conversion was 88%.

The FT-IR analysis revealed bands of 1,553 cm ^-1 , 1,480 cm ^-1 (C = N) and 1,058 cm ^-1 (CO), which are polybenzoxazole characteristic bands that were not present in polyhydroxyimide. In addition, the prepared polymer had a free volume of 0.214 and an interplanar distance of 575.2 pm.

In addition, the full width at half maximum (FWHM) by positron annihilation lifetime spectroscopy (PALS) was 25.3 pm.

Example  6: Preparation of Polymer Electrolyte Membrane for Fuel Cell

A polymer electrolyte membrane for a fuel cell including a polybenzoxazole including a repeating unit represented by Chemical Formula 51 was prepared in the same manner as in Example 1 except that the nonwoven fabric was heat treated at 425 ° C. for 3 hours. Thermal conversion was 91%.

The FT-IR analysis revealed bands of 1,553 cm ^-1 , 1,480 cm ^-1 (C = N) and 1,058 cm ^-1 (CO), which are polybenzoxazole characteristic bands that were not present in polyhydroxyimide. In addition, the prepared polymer had a free volume of 0.215 and an interplanar distance of 576.4 pm.

In addition, the full width at half maximum (FWHM) measured by positron annihilation lifetime spectroscopy (PALS) was 26.2 pm.

Example  7: Preparation of polymer electrolyte membrane for fuel cell

A polymer electrolyte membrane for a fuel cell including a polybenzoxazole including a repeating unit represented by Chemical Formula 51 was prepared in the same manner as in Example 1 except that the nonwoven fabric was heat treated at 450 ° C. for 1 hour. Thermal conversion was 95%.

The FT-IR analysis revealed bands of 1,553 cm ^-1 , 1,480 cm ^-1 (C = N) and 1,058 cm ^-1 (CO), which are polybenzoxazole characteristic bands that were not present in polyhydroxyimide. In addition, the prepared polymer had a free volume of 0.217 and an interplanar distance of 578 pm.

In addition, the full width at half maximum (FWHM) measured by positron annihilation lifetime spectroscopy (PALS) was 26.9 pm.

Comparative example  1: Preparation of Polymer Electrolyte Membrane for Fuel Cell

A polymer electrolyte membrane for a fuel cell including a polymer including a polyimide including a repeating unit represented by the following Chemical Formula 52 was prepared from a polyamic acid as represented by Scheme 2 below.

Scheme 2

(1) Preparation of Polyamic Acid

2.94 g (10 mmol) of 3,3 ', 4,4'-biphenyl tetracapcarboxyl dianhydride and 4,4'-diaminodiphenyl 2.00 g (10 mmol) of ether (4,4'-diaminodiphenyl ether) was added to 20 ml of dimethylacetamide (DMAc), and reacted at 15 ° C. for 4 hours to prepare a polyamic acid solution having a pale yellow viscosity. The weight average molecular weight of the polyamic acid was 120,000.

(2) Preparation of Porous Support Comprising Polyimide

Dimethylformamide (DMF) was added to the prepared polyamic acid solution to prepare a composition for forming a porous support including 25 wt% of the polyamic acid.

Using the drum-type electrospinning equipment for forming the porous support, +12 kV is applied to the cylinder portion and -4 kV to the drum portion, and the radial interval is 15 cm, flow rate 0.1 μl / min, and drum speed 50 rpm. Electrospinning to prepare a nonwoven fabric containing the fiber.

Subsequently, the prepared nonwoven fabric was heat-treated at 350 ° C. for 1 hour, and then slowly cooled to room temperature to prepare a porous support including polyimide. The temperature increase rate at the time of the said heat processing was 5 degree-C / min.

The porosity of the porous support measured using a capillary flow porometer device was 65%. In addition, the porous support had a thickness of 43 μm.

(4) Preparation of Polymer Electrolyte Membrane for Fuel Cell Containing Polyimide

The porous support was immersed in a solution of 10 g of sulfonated-poly (arylene ether sulfone: s-PAES) in 90 g of dimethylformamide (DMF) for 1 hour, By drying slowly in an oven, a polymer electrolyte membrane for a fuel cell containing polyimide was prepared.

A result of FT-IR analysis, it was confirmed that a polyimide characteristic band of 1787 cm ^-1, a band of 1731cm ^-1, 1360 cm ^-1 and 724 cm ^-1. In addition, the prepared polymer had a free volume of 0.12 and an interplanar distance of 520 pm.

Test Example  1: picture

The porous support prepared in Examples 1 to 7 and Comparative Example 1 was photographed using a general camera. Among them, the photo of the porous support prepared in Example 4 is shown in FIG.

The fuel cell polymer electrolyte membranes prepared in Examples 1 to 7 and Comparative Example 1 were photographed using a general camera. Among these, the photo of the fuel cell polymer electrolyte membrane prepared in Example 4 is shown in FIG.

As shown in Figure 3 and 4, it can be seen that the porous support prepared in Example 4 is effectively wetted by cation exchange resin is changed to transparent. As a result, the porous support prepared in Example 4 can be confirmed that the cation exchange resin is well impregnated with excellent wettability to the cation exchange resin.

Test Example  2: proton conductivity evaluation

After cutting the polymer electrolyte membrane for fuel cells prepared in Examples 1 to 7 and Comparative Example 1 to a size of 1 cm × 4 cm, the impedance / gain phase analyzer (Solartron 1260) and the electrochemical interface (Solartron 1287, Farnborough, Hampshire, UK R) was measured by fixing the polymer electrolyte membrane for each fuel cell to the equipment, and the proton conductivity was calculated through Equation 4 below. Among them, the results for Example 4 are shown in Table 1 below.

&Quot; (4) "

Proton Conductivity = d / (L _s ⅹ W _s ⅹ R)

d: distance between electrodes

L _s : Thickness of polymer electrolyte membrane for fuel cell

W _s : width of polymer electrolyte membrane for fuel cell (1 cm)

R: resistance

Test Example  3: water absorption rate ( water uptake Evaluation of characteristics

The polymer electrolyte membrane for fuel cells prepared in Examples 1 to 7 and Comparative Example 1 was cut to a size of 4 cm × 4 cm.

Next, the weight (W _d ) of the dry state of each polymer electrolyte membrane for fuel cell was measured.

Subsequently, each of the fuel cell polymer electrolyte membranes was immersed in distilled water (deionized water) at 80 ° C. for 24 hours. Next, each of the fuel cell polymer electrolyte membranes was taken out and the weight (W _w ) of the fuel cell polymer electrolyte membrane was measured.

The moisture absorption rate was calculated by substituting the measured weight value into the following Equation 5.

[Equation 5]

Water absorption rate (%) = ((W _w -W _d ) / W _d ) ⅹ100

W _d : dry weight of the polymer electrolyte membrane for a fuel cell

W _w : Weight after hydration of the polymer electrolyte membrane for fuel cell

Test Example  4: Dimensional stability evaluation

The polymer electrolyte membrane for fuel cells prepared in Examples 1 to 7 and Comparative Example 1 was cut to a size of 4 cm × 4 cm. Each polymer electrolyte membrane for fuel cells was then dried in a vacuum oven at 100 ° C. for 24 hours. In the dry state, the length and width of each of the polymer electrolyte membranes for fuel cells were measured.

Subsequently, the polymer electrolyte membranes for each fuel cell were immersed in distilled water (deionized water) at 80 ° C., and then left for one day. Each of the hydrated fuel cell polymer electrolyte membranes was taken out to measure the length and width of the fuel cell polymer electrolyte membrane.

The length and width of the polymer electrolyte membrane for fuel cells may be adjusted using a video microscope system ICS-305B (manufactured by Sometech) in order to reduce errors due to rapid desorption of water molecules in the hydrated fuel cell polymer electrolyte membrane. Measured.

The dimensional stability was evaluated by substituting the measured length and width of the fuel cell polymer electrolyte membrane into the following equation (6). Dimensional stability was evaluated here using the length of the polymer electrolyte membrane for fuel cells.

&Quot; (6) "

Dimensional change (%) = ((D _wet -D _dry ) / D _dry ) ⅹ100

D _dry : Dimension (length or width) of polymer electrolyte membrane for dry fuel cell

D _wet : Dimension (length or width) of the polymer electrolyte membrane for hydrated fuel cell

Proton conductivity
(S / cm, 80 ℃) Water absorption
(%, 80 ℃) Dimensional stability
(%, 80 ℃) Example 4 0.095 39.28 23.57 Comparative Example 1 0.08 > 100 30

As shown in Table 1, it can be seen that the polymer electrolyte membrane for fuel cells prepared in Example 4 has better proton conductivity than the polymer electrolyte membrane for fuel cells prepared in Comparative Example 1, and at the same time exhibits low water absorption and high dimensional stability. have.

Although specific embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to the scope of the invention.

20: membrane-electrode assembly for fuel cell, 22: anode,
24: polymer electrolyte membrane, 26: cathode,
244 porous support, 242 cation exchange resin,
1: fuel cell system, 3: electricity generator,
5: fuel supply, 7: oxidant supply,
9: fuel tank, 11: fuel pump,
13: oxidant pump, 17: membrane-electrode assembly,
19, 19 ': Separator, 15: Stack

Claims (53)

A porous support comprising a polymer derived from polyamic acid or a polymer derived from polyimide,
The porous support has micropores and picopores present in the polymer derived from the polyamic acid or picopores present in the polymer derived from the polyimide,
Wherein said polyamic acid and said polyimide comprise repeating units made from aromatic diamines and dianhydrides comprising at least one functional group present at the ortho position relative to the amine group.
The method of claim 1,
Wherein said functional group comprises OH, SH or NH ₂ .
The method of claim 1,
The polymer is induced by thermal conversion from the polyamic acid or the polyimide, and the ratio (thermal conversion rate) of the thermally converted repeating unit to the total amount of repeating units included in the polyamic acid or the polyimide is 10 mol%. To 100 mol% of the porous support.
The method of claim 1,
The polymer derived from the polyamic acid and the polymer derived from the polyimide have a free volume (FFV) of 0.18 to 0.40.
The method of claim 1,
The polymer derived from the polyamic acid and the polymer derived from the polyimide has a surface-to-face distance by XRD measurement in the range of 550 pm to 800 pm.
The method of claim 1,
The picopores are two or more connected to each other to form an hourglass shape (hourglass shaped).
The method of claim 1,
The picopore is a porous support in which the full width at half maximum (FWHM) by positron annihilation lifetime spectroscopy (PALS) is in the range of 10 pm to 40 pm.
The method of claim 1,
The porous support is a porous support having a porosity of 10% to 95% by volume relative to the total volume of the support.
The method of claim 1,
The porous support is one having a thickness of 10 ㎛ to 200 ㎛.
The method of claim 1,
The polyamic acid is a polyamic acid including a repeating unit represented by the following Chemical Formulas 1 to 4, a polyamic acid copolymer comprising a repeating unit represented by the following Chemical Formulas 5 to 8, copolymers thereof, and blends thereof Selected,
The polyimide is a polyimide comprising a repeating unit represented by the following formulas 19 to 22, a polyimide copolymer comprising a repeating unit represented by the following formulas 23 to 26, copolymers thereof and blends thereof The porous support that is selected:
[Formula 1]

(2)

(3)

[Chemical Formula 4]

[Chemical Formula 5]

[Formula 6]

[Formula 7]

[Chemical Formula 8]

[Chemical Formula 19]

[Chemical Formula 20]

[Chemical Formula 21]

[Chemical Formula 22]

(23)

[Formula 24]

[Formula 25]

[Formula 26]

In Chemical Formulas 1 to 8 and 19 to 26,
Ar ₁ is an aromatic ring group selected from a substituted or unsubstituted tetravalent C6 to C24 arylene group and a substituted or unsubstituted tetravalent C4 to C24 heterocyclic group, wherein the aromatic ring group is present alone; Two or more are joined to each other to form a condensed ring; Two or more single bonds, O, S, C (= 0), CH (OH), S (= 0) ₂ , Si (CH ₃ ) ₂ , (CH ₂ ) _p (where 1 ≦ _p ≦ 10) , (CF ₂ ) _q (where 1 ≦ _q ≦ 10), C (CH ₃ ) ₂ , C (CF ₃ ) ₂ or C (═O) NH, and
Ar ₂ is an aromatic ring group selected from a substituted or unsubstituted divalent C6 to C24 arylene group and a substituted or unsubstituted divalent C4 to C24 heterocyclic group, wherein the aromatic ring group is present alone; Two or more are joined to each other to form a condensed ring; Two or more single bonds, O, S, C (= 0), CH (OH), S (= 0) ₂ , Si (CH ₃ ) ₂ , (CH ₂ ) _p (where 1 ≦ _p ≦ 10) , (CF ₂ ) _q (where 1 ≦ _q ≦ 10), C (CH ₃ ) ₂ , C (CF ₃ ) ₂ or C (═O) NH, and
Q is O, S, C (= O), CH (OH), S (= O) ₂ , Si (CH ₃ ) ₂ , (CH ₂ ) _p (where 1 ≦ _p ≦ 10), (CF ₂ ) _q (where 1 ≦ _q ≦ 10), C (CH ₃ ) ₂ , C (CF ₃ ) ₂ , C (═O) NH, C (CH ₃ ) (CF ₃ ), or a substituted or unsubstituted phenylene group Wherein the substituted phenylene group is substituted with a C1 to C6 alkyl group or a C1 to C6 haloalkyl group, wherein Q is linked to both aromatic rings in the mm, mp, pm, or pp position,
Y is the same or different at each repeating unit, each independently OH, SH or NH ₂ ,
n is an integer satisfying 20 ≦ n ≦ 200,
m is an integer satisfying 10≤m≤400,
l is an integer satisfying 10 ≦ l ≦ 400.
The method of claim 10,
Ar ₁ is a porous support selected from _one of the following formulae:

Where
X ₁ , X ₂ , X ₃ and X ₄ are the same or different from each other and each independently O, S, C (= 0), CH (OH), S (= 0) ₂ , Si (CH ₃ ) ₂ , ( CH ₂ ) _p (where 1 ≦ _p ≦ 10), (CF ₂ ) _q (where 1 ≦ _q ≦ 10), C (CH ₃ ) ₂ , C (CF ₃ ) ₂ , or C (═O) NH ego,
W ₁ and W ₂ are the same or different and are each independently O, S, or C (═O),
Z ₁ is O, S, CR ₁₀₀ R ₁₀₁ or NR ₁₀₂ , wherein R ₁₀₀ , R ₁₀₁ and R ₁₀₂ are the same or different from each other and are each independently hydrogen or a C1 to C5 alkyl group,
Z ₂ and Z ₃ are the same or different from each other and independently of each other N or CR ₁₀₃ (wherein R ₁₀₃ is hydrogen or a C1 to C5 alkyl group) but not CR ₁₀₃ at the same time,
R ₁ to R ₄₂ are the same or different and are each independently hydrogen or a substituted or unsubstituted C1 to C10 aliphatic organic group,
k1 to k3, k8 to k14, k24 and k25 are integers of 0 to 2,
k5, k15, k16, k19, k21 and k23 are integers of 0 or 1,
k4, k6, k7, k17, k18, k20, k22, k26 to k29, k31, k34 to k36, k38, k39 and k42 are integers from 0 to 3,
k30, k37, k40 and k41 are integers from 0 to 4,
k32 and k33 are integers of 0-5.
The method of claim 11,
Ar ₁ is a porous support selected from _one of the following formulae:

The method of claim 10,
Ar ₂ is a porous support selected from those represented by the following formula:

Where
X ₁ , X ₂ , X ₃ and X ₄ are the same or different from each other and each independently O, S, C (= 0), CH (OH), S (= 0) ₂ , Si (CH ₃ ) ₂ , ( CH ₂ ) _p (where 1 ≦ _p ≦ 10), (CF ₂ ) _q (where 1 ≦ _q ≦ 10), C (CH ₃ ) ₂ , C (CF ₃ ) ₂ , or C (═O) NH ego,
W ₁ and W ₂ are the same or different and are each independently O, S, or C (═O),
Z ₁ is O, S, CR ₁₀₀ R ₁₀₁ or NR ₁₀₂ , wherein R ₁₀₀ , R ₁₀₁ and R ₁₀₂ are the same or different from each other and are each independently hydrogen or a C1 to C5 alkyl group,
Z ₂ and Z ₃ are the same or different from each other and independently of each other N or CR ₁₀₃ (wherein R ₁₀₃ is hydrogen or a C1 to C5 alkyl group) but not CR ₁₀₃ at the same time,
R ₄₃ to R ₈₉ are the same or different from each other and are each independently hydrogen, a substituted or unsubstituted C1 to C10 aliphatic organic group, or a metal sulfonate group,
k43, k49, k64 to k68, k72 to k76, and k82 to k89 are integers of 0 to 4,
k44 to k46, k48, k51, k54, k55, k57, k58, k61 and k63 are integers from 0 to 3,
k47, k52, k53, k56, k59, k60, k62, k70, k78, k80 and k81 are integers from 0 to 2,
k50 is an integer of 0 or 1,
k69, k71, k77 and k79 are integers of 0-5.
The method of claim 13,
Ar ₂ is a porous support selected from those represented by the following formula:

Wherein M is a metal and the metal is sodium, potassium, lithium, alloys thereof or combinations thereof.
The method of claim 10,
Q is selected from C (CH ₃ ) ₂ , C (CF ₃ ) ₂ , O, S, S (= 0) ₂ or C (= 0).
The method of claim 10,
Ar ₁ is a functional group represented by any one of Formulas A1 to A8, Ar ₂ is a functional group represented by any one of Formulas B1 to B11, and Q is C (CF ₃ ) ₂ .
[Formula A1] [Formula A2] [Formula A3]

[Formula A4] [Formula A5] [Formula A6]

Formula A7 Formula A8

[Formula B1] [Formula B2] [Formula B3]

[Formula B4] [Formula B5] [Formula B6] [Formula B7]

Formula B8 Formula B9

[Formula B10] [Formula B11]

.
The method of claim 10,
The molar ratio between each repeating unit in the copolymer of the polyamic acid including the repeating unit represented by the formula 1 to 4, the molar ratio of m: l in the formula 5 to 8, the repeating unit represented by the formula 19 to 22 The molar ratio between each repeating unit in the copolymer of the polyimide containing, or the molar ratio of m: l in the formula 23 to 26 is 0.1: 9.9 to 9.9: 0.1.
The method of claim 1,
The polymer is derived from the polyamic acid and the polymer derived from the polyimide is a porous support comprising a polymer or a copolymer thereof comprising a repeating unit represented by any one of the following formulas 37 to 50:
[Formula 37]

[Formula 38]

[Formula 39]

[Formula 40]

[Formula 41]

[Formula 42]

[Formula 43]

[Formula 44]

[Formula 45]

[Formula 46]

[Formula 47]

[Formula 48]

[Formula 49]

[Formula 50]

In Chemical Formulas 37 to 50,
Ar ₁ is an aromatic ring group selected from a substituted or unsubstituted tetravalent C6 to C24 arylene group and a substituted or unsubstituted tetravalent C4 to C24 heterocyclic group, wherein the aromatic ring group is present alone; Two or more are joined to each other to form a condensed ring; Two or more single bonds, O, S, C (= 0), CH (OH), S (= 0) ₂ , Si (CH ₃ ) ₂ , (CH ₂ ) _p (where 1 ≦ _p ≦ 10) , (CF ₂ ) _q (where 1 ≦ _q ≦ 10), C (CH ₃ ) ₂ , C (CF ₃ ) ₂ or C (═O) NH, and
Ar ₁ ′ and Ar ₂ are the same or different from each other and are each independently an aromatic ring group selected from a substituted or unsubstituted divalent C6 to C24 arylene group and a substituted or unsubstituted divalent C4 to C24 heterocyclic group, Aromatic ring groups are present alone; Two or more are joined to each other to form a condensed ring; Two or more single bonds, O, S, C (= 0), CH (OH), S (= 0) ₂ , Si (CH ₃ ) ₂ , (CH ₂ ) _p (where 1 ≦ _p ≦ 10) , (CF ₂ ) _q (where 1 ≦ _q ≦ 10), C (CH ₃ ) ₂ , C (CF ₃ ) ₂ or C (═O) NH, and
Q is O, S, C (= O), CH (OH), S (= O) ₂ , Si (CH ₃ ) ₂ , (CH ₂ ) _p (where 1 ≦ _p ≦ 10), (CF ₂ ) _q (where 1 ≦ _q ≦ 10), C (CH ₃ ) ₂ , C (CF ₃ ) ₂ , C (═O) NH, C (CH ₃ ) (CF ₃ ), or a substituted or unsubstituted phenylene group Wherein the substituted phenylene group is substituted with a C1 to C6 alkyl group or a C1 to C6 haloalkyl group, wherein Q is linked to both aromatic rings in the mm, mp, pm, or pp position,
Y '' is O or S,
n is an integer satisfying 20 ≦ n ≦ 200,
m is an integer satisfying 10≤m≤400,
l is an integer satisfying 10 ≦ l ≦ 400.
The method of claim 18,
Ar ₁ is a porous support selected from _one of the following formulae:

Where
X ₁ , X ₂ , X ₃ and X ₄ are the same or different from each other and each independently O, S, C (= 0), CH (OH), S (= 0) ₂ , Si (CH ₃ ) ₂ , ( CH ₂ ) _p (where 1 ≦ _p ≦ 10), (CF ₂ ) _q (where 1 ≦ _q ≦ 10), C (CH ₃ ) ₂ , C (CF ₃ ) ₂ , or C (═O) NH ego,
W ₁ and W ₂ are the same or different and are each independently O, S, or C (═O),
Z ₁ is O, S, CR ₁₀₀ R ₁₀₁ or NR ₁₀₂ , wherein R ₁₀₀ , R ₁₀₁ and R ₁₀₂ are the same or different from each other and are each independently hydrogen or a C1 to C5 alkyl group,
Z ₂ and Z ₃ are the same or different from each other and independently of each other N or CR ₁₀₃ (wherein R ₁₀₃ is hydrogen or a C1 to C5 alkyl group) but not CR ₁₀₃ at the same time,
R ₁ to R ₄₂ are the same or different and are each independently hydrogen or a substituted or unsubstituted C1 to C10 aliphatic organic group,
k1 to k3, k8 to k14, k24 and k25 are integers of 0 to 2,
k5, k15, k16, k19, k21 and k23 are integers of 0 or 1,
k4, k6, k7, k17, k18, k20, k22, k26 to k29, k31, k34 to k36, k38, k39 and k42 are integers from 0 to 3,
k30, k37, k40 and k41 are integers from 0 to 4,
k32 and k33 are integers of 0-5.
The method of claim 19,
Ar ₁ is a porous support selected from _one of the following formulae:

The method of claim 18,
Wherein Ar ₁ ′ and Ar ₂ are selected from those represented by the following formulas:

Where
X ₁ , X ₂ , X ₃ and X ₄ are the same or different from each other and each independently O, S, C (= 0), CH (OH), S (= 0) ₂ , Si (CH ₃ ) ₂ , ( CH ₂ ) _p (where 1 ≦ _p ≦ 10), (CF ₂ ) _q (where 1 ≦ _q ≦ 10), C (CH ₃ ) ₂ , C (CF ₃ ) ₂ , or C (═O) NH ego,
W ₁ and W ₂ are the same or different and are each independently O, S, or C (═O),
Z ₁ is O, S, CR ₁₀₀ R ₁₀₁ or NR ₁₀₂ , wherein R ₁₀₀ , R ₁₀₁ and R ₁₀₂ are the same or different from each other and are each independently hydrogen or a C1 to C5 alkyl group,
Z ₂ and Z ₃ are the same or different from each other and independently of each other N or CR ₁₀₃ (wherein R ₁₀₃ is hydrogen or a C1 to C5 alkyl group) but not CR ₁₀₃ at the same time,
R ₄₃ to R ₈₉ are the same or different from each other and are each independently hydrogen, a substituted or unsubstituted C1 to C10 aliphatic organic group, or a metal sulfonate group,
k43, k49, k64 to k68, k72 to k76, and k82 to k89 are integers of 0 to 4,
k44 to k46, k48, k51, k54, k55, k57, k58, k61 and k63 are integers from 0 to 3,
k47, k52, k53, k56, k59, k60, k62, k70, k78, k80 and k81 are integers from 0 to 2,
k50 is an integer of 0 or 1,
k69, k71, k77 and k79 are integers of 0-5.
The method of claim 21,
Wherein Ar ₁ ′ and Ar ₂ are selected from those represented by the following formulas:

Wherein M is a metal and the metal is sodium, potassium, lithium, alloys thereof or combinations thereof.
The method of claim 18,
Q is selected from C (CH ₃ ) ₂ , C (CF ₃ ) ₂ , O, S, S (= 0) ₂ or C (= 0).
The method of claim 18,
Ar ₁ is a functional group represented by any one of Formulas A1 to A8, Ar ₁ ′ is a functional group represented by any one of Formulas C1 to C8, and Ar ₂ is a functional group represented by any one of Formulas B1 to B11 Wherein Q is C (CF ₃ ) ₂ ;
[Formula A1] [Formula A2] [Formula A3]

[Formula A4] [Formula A5] [Formula A6]

Formula A7 Formula A8

[Formula B1] [Formula B2] [Formula B3]

[Formula B4] [Formula B5] [Formula B6] [Formula B7]

Formula B8 Formula B9

[Formula B10] [Formula B11]

[Formula C1] [Formula C2] [Formula C3]

[Formula C4] [Formula C5] [Formula C6]

Formula C7 Formula C8

.
The method of claim 1,
The porous support includes a fiber comprising a polymer having the picopores, wherein the fibers are randomly arranged.
The method of claim 1,
The porous support includes a fiber comprising a polymer having the picopores, wherein the fibers are arranged in one direction.
27. A porous support according to any one of claims 1 to 26; And
Polymer electrolyte membrane for a fuel cell comprising a cation exchange resin formed on the inside, the surface, or the inside and the surface of the porous support.
The method of claim 27,
The cation exchange resin is a polymer electrolyte membrane for a fuel cell is a polymer comprising a cation exchange group selected from the group consisting of sulfonic acid group, carboxylic acid group, phosphoric acid group, phosphonic acid group and derivatives thereof.
The method of claim 27,
The porous support and the cation exchange resin is a polymer electrolyte membrane for a fuel cell comprising a weight ratio of 99: 1 to 10:90.
The method of claim 27,
The fuel cell polymer electrolyte membrane has a thickness of 20 μm to 300 μm.
A porous support according to any one of claims 1 to 26,
A polymer electrolyte membrane for a fuel cell, which is formed by doping an acid into the inside, the surface, or inside and the surface of the porous support.
32. The method of claim 31,
The acid is selected from the group consisting of sulfonic acid, carboxylic acid, phosphoric acid, phosphonic acid and derivatives thereof.
A porous support according to any one of claims 1 to 26,
The porous support is a polymer electrolyte membrane for a fuel cell comprising a fluorine group on the surface.
Polyamic acid or polyimide having repeating units prepared from aromatic diamines and dianhydrides comprising at least one functional group present at the ortho position relative to the amine group; And
Contains an organic solvent,
The organic solvent is dimethyl sulfoxide; N-methyl-2-pyrrolidone; N-methylpyrrolidone; N, N-dimethylformamide; N, N-dimethylacetamide; ketones selected from the group consisting of γ-butyrolactone, cyclohexanone, 3-hexanone, 3-heptanone, and 3-octanone; And composition for forming a porous support that is selected from the group consisting of these.
The method of claim 34, wherein
1 to 40% by weight of the polyamic acid or the polyimide, and 60 to 99% by weight of the organic solvent, based on the total amount of the composition for forming the porous support.
The method of claim 34, wherein
The composition for forming the porous support
water; Alcohols selected from the group consisting of methanol, ethanol, 2-methyl-1-butanol, 2-methyl-2-butanol, glycerol, ethylene glycol, diethylene glycol and propylene glycol; Ketones selected from the group consisting of acetone and methylethyl ketone; A polymer compound selected from the group consisting of polyvinyl alcohol, polyacrylic acid, polyacrylamide, polyethylene glycol, polypropylene glycol, chitosan, chitin, dextran and polyvinylpyrrolidone; Tetrahydrofuran; Trichloroethane; And a composition selected from the group consisting of a combination thereof.
The method of claim 36,
1 to 40% by weight of the polyamic acid or the polyimide, 10 to 95% by weight of the organic solvent and 4 to 70% by weight of the auxiliary agent, based on the total amount of the composition for forming the porous support including the auxiliary agent. A composition for forming a phosphorous porous support.
The method of claim 34, wherein
Wherein said polyamic acid and said polyimide each have a weight average molecular weight (Mw) of 10,000 g / mol to 500,000 g / mol.
The method of claim 34, wherein
The composition for forming a porous support is a composition for forming a porous support having a viscosity of 0.01 Pa.s to 100 Pa.s.
40. A method for forming a nonwoven fabric by electrospinning a composition for forming a porous support according to any one of claims 34 to 39; And
Heat-treating the nonwoven fabric to form a porous support comprising a polymer derived from polyamic acid or a polymer derived from polyimide
Method for producing a porous support comprising a.
The method of claim 40,
The electrospinning method of producing a porous support that is carried out by applying a voltage of 1 kV to 1,000 kV.
The method of claim 40,
The nonwoven fabric is a method of producing a porous support that is randomly arranged fibers comprising the composition for forming a porous support.
The method of claim 40,
The nonwoven fabric is a method for producing a porous support is that the fibers comprising the composition for forming the porous support is arranged in one direction.
The method of claim 40,
The polymer is induced by thermal conversion from the polyamic acid or the polyimide, and the ratio (thermal conversion rate) of the thermally converted repeating unit to the total amount of repeating units included in the polyamic acid or the polyimide is 10 mol%. It is to 100 mol% of the method for producing a porous support.
The method of claim 40,
The heat treatment is a method of producing a porous support that is carried out at a temperature of 250 ℃ to 550 ℃.
The method of claim 40,
The heat treatment is a method for producing a porous support that is carried out for 10 minutes to 5 hours.
The method of claim 40,
The temperature increase rate during the heat treatment is 1 ℃ / min to 20 ℃ / min method for producing a porous support.
40. A method for forming a nonwoven fabric by electrospinning a composition for forming a porous support according to any one of claims 34 to 39;
Heat treating the nonwoven fabric to form a porous support comprising a polymer derived from polyamic acid or a polymer derived from polyimide; And
Forming a cation exchange resin on the inside, the surface, or the inside and the surface of the porous support
Method for producing a polymer electrolyte membrane for a fuel cell comprising a.
40. A method for forming a nonwoven fabric by electrospinning a composition for forming a porous support according to any one of claims 34 to 39;
Heat treating the nonwoven fabric to form a porous support comprising a polymer derived from polyamic acid or a polymer derived from polyimide; And
Doping acid into the interior, surface, or interior and surface of the porous support
Method for producing a polymer electrolyte membrane for a fuel cell comprising a.
The method of claim 49,
The acid is selected from the group consisting of sulfonic acid, carboxylic acid, phosphoric acid, phosphonic acid and derivatives thereof.
40. A method for forming a nonwoven fabric by electrospinning a composition for forming a porous support according to any one of claims 34 to 39;
Heat treating the nonwoven fabric to form a porous support comprising a polymer derived from polyamic acid or a polymer derived from polyimide; And
Introducing a fluorine group to the surface of the porous support
Method for producing a polymer electrolyte membrane for a fuel cell comprising a.
Anodes and cathodes positioned opposite one another; And
Located between the anode and the cathode, a polymer for a fuel cell comprising a porous support according to any one of claims 1 to 28 and the cation exchange resin formed on the inside, surface, or inside and surface of the porous support. Membrane-electrode assembly for a fuel cell comprising an electrolyte membrane.
An electricity generation unit including at least one membrane-electrode assembly and a separator according to claim 52, wherein the electricity generation unit generates electricity through an electrochemical reaction between a fuel and an oxidant;
A fuel supply unit supplying fuel to the electricity generation unit; And
Oxidant supply unit for supplying an oxidant to the electricity generating unit
Fuel cell system comprising a.

Images