KR101857152B1 - Latent ion-conducting polymer, resin composition comprising the polymer, and manufacturing method of ion-conducting membrane using the same - Google Patents

Abstract

Provided is a latent ion conductive polymer including a latent ion conductive substituent as a pendant substituent substituted on a main chain which forms the polymer. Moreover, provided are a polymeric resin composition containing the same, and a method for producing an ion conductive membrane thereby. According to the present invention, it is possible to produce ion conductive membranes having ion channels whose morphology is suitably controlled in a fluorine-based matrix which is excellent in chemical and mechanical stability, by using the latent ion conductive polymer.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an ion conductive polymer, a resin composition containing the ion conductive polymer, and a method for manufacturing an ion conductive membrane using the same. BACKGROUND ART [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a potential ion conductive polymer, a resin composition containing the same, and a process for producing an ion conductive membrane using the same. More particularly, the present invention relates to a process for producing an ion conductive membrane including a polymer block having neutral ion conductivity A potential ion conductive polymer capable of easily controlling the morphology of the ionic channel formed in the ion conductive film produced from the solvent and capable of forming a stable ion channel, And a method for producing an ion conductive membrane using the same.

Polymer electrolytes for fuel cells are one of the key components of the fuel cell, which affects the fuel cell performance. The production cost of the catalyst electrode including the polymer electrolyte and the binder accounts for about 50% of the fuel cell production cost.

A widely used material for the ion conductive membrane applied to the polymer electrolyte is Nafion (registered trademark) of DuPont, which is based on a polymer in which a sulfonic acid group is introduced into the skeleton of polytetrafluoroethylene. Nafion has the advantages of chemical stability, thermal stability and high ionic conductivity, but there are problems such as high cost, dehydration at high temperature, methanol permeation, and so on.

As an example of an alternative technique, a technique of impregnating a hydrophobic porous film with Nafion is known . This technology is the most potent alternative to Nafion at present, but it is still expensive in that it can be used at high Nafion usage and can maintain high temperature functionality and mechanical stability.

As an attempt to overcome the problem of Nafion's high temperature dehydration, a method of crosslinking Nafion resin has been proposed. However, the method has a fundamental problem that the ionic conductivity can not be secured.

Another approach is to apply a hydrocarbon-based ionic polymer. However, the hydrocarbon-based polymer is still not an alternative to the naphion-based polymer because of its relatively low chemical stability and ionic conductivity compared with fluoropolymers such as nafion.

Finally, attempts have been made to secure an ion channel by using the self-assembly phenomenon of a hydrocarbon-based block copolymer. The ionic conductive membrane produced by this method is still unsatisfactory in mechanical and chemical stability. Further, The manufacturing process is complicated due to the amphipathic nature of the polymer.

Accordingly, the present inventors have made efforts to find a new material capable of overcoming the disadvantages of the prior art described above. As a result, the inventors have found that a hydrocarbon copolymer having potential ion conductivity is blended with a fluoropolymer, It has been confirmed that an ion conductive membrane having excellent chemical and mechanical stability can be obtained while ensuring a stable ion channel when the ion conductive membrane is converted into an ion channel after inducing the assembly phenomenon.

It is an object of the present invention to provide a potential ion conductive polymer capable of producing an ion conductive membrane capable of forming a controlled type ion channel having excellent chemical and mechanical stability such as a fluorinated polymer.

Another object of the present invention is to provide a polymer resin composition comprising the polymer.

It is still another object of the present invention to provide a method for producing an ion conductive membrane using the above composition.

Another object of the present invention is to provide an ion conductive membrane produced by the above method.

In order to achieve the above object, the present invention provides a potential ion-conducting polymer comprising a potential ion-conducting substituent as a pendant substituent substituted on the main chain forming the polymer.

Also, the present invention provides a polymer electrolyte membrane comprising: a first polymer comprising the potential ion conductive polymer; And a second polymer comprising an emissive resin for the potential ion conductive polymer.

The potential ion conductive polymer may be poly (alkyl p-styrene sulfonate).

The first polymer may be a block copolymer of a latent ion conductive polymer and a non-polar acrylic polymer.

The second polymer resin may be a fluorine-based or partially fluorine-based polymer resin.

According to another aspect of the present invention, there is provided a method of manufacturing a polymer electrolyte fuel cell, comprising the steps of: casting a polymer resin composition comprising a first polymer containing a latent ion conductive polymer and a second polymer including a resin incompatible with the potential ion conductive polymer; After the casting, inducing self-assembly of the potentially ion conductive polymer block to obtain a film precursor film; And converting the self-assembled potential ion conductive polymer to an ion conductive polymer to form an ion channel.

The present invention also provides an ion conductive film produced by the above method, wherein an ion channel of a polar polymer resin is formed in a fluorine resin matrix.

By using the composition of the present invention, a potential ion-conductive channel is formed in a polymer matrix, for example, a fluorine-based polymer matrix, and then converted into an ionic channel having an ionic property to form an ionic channel in the polymer matrix A conductive film can be produced.

The ion conductive membrane prepared according to the composition of the present invention may have ion channels of well-controlled morphology in a matrix resin excellent in chemical and mechanical stability. Therefore, an ion conductive membrane having an ion conductive channel having stable and high conductivity can be produced.

The potential ion conductive polymer included in the composition of the present invention is a nonionic neutral compound. Therefore, in the case of blending with the fluorine-based polymer, there is no limitation on the solvent depending on the difference in ionicity. Therefore, the ion conductive film can be produced by a simple process.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram for explaining a change in morphology of a film in a method for producing an ion conductive membrane of the present invention. FIG.
FIG. 2A shows GPC results for PNSSs synthesized in the embodiment, and FIG. 2B is a comparison of GPC results of PNSS and PNSS-b-PMMA.
FIG. 3A is a ¹ H NMR spectrum of PNSS-PMMA having a molecular weight Mn of 15,000 g / mol, and FIG. 3 b is an IR spectrum.
4 is a graph showing a change in weight with time while the film precursor film is heat-treated.
FIG. 5 is an ATM photograph of a self-assembled film precursor film after drying is completed and a surface of an ion conductive membrane on which an ion channel is formed after heat treatment is completed.
6 is a graph showing the water absorption rate of the produced ion conductive membrane over time.
7 is a graph showing the ionic conductivity of the ion conductive membrane prepared according to the method of the present invention.

In the present invention, the term " ionic substituent or polymer " refers not only to a case where an ionic substituent such as an alkali metal salt of a sulfonic acid is present on all or a part of a molecule, A polymer having an acid substituent capable of being converted to an ionic substituent. In the present invention, "neutral" or "nonionic" polymer refers to a polymer having no ionic substituent.

In the present invention, a `potential ion conductive` substituent or polymer refers to a substance which is neutral and has no ionic conductivity, but can be converted into a substituent or polymer having an ionic moiety when subjected to an appropriate treatment. The process of converting the potential ionic conductivity to ionic conductivity may be, for example, heat treatment; Chemical treatments such as acids and bases; Or a light treatment such as visible light, UV- or electron beam irradiation. These treatments can be used in combination.

In the present invention, the term `self-assembly 'refers to a process in which each block of a copolymer containing an incompatible polymer or an incompatible polymer block contained in the composition is rearranged according to the properties of the polymer or unit blocks . The nature of the polymers, or blocks, to derive the self-assembly is a physical interaction such as surface tension, hydrophilic / lipophilic or ionic / nonionic properties. The result of the rearrangement usually involves phase separation.

In the present invention, the term "pendant substituent" refers to a substituted atom or group in place of hydrogen bonded to an atom such as carbon or nitrogen which forms the main chain of the polymer. The pendant substituent may be a form in which an atomic group containing a functional group is directly bonded to the main chain, or an atomic group containing a main chain and a functional group is a carbon atom and / or a hetero atom containing a C1 to C10 hetero atom May be in the form in which an atomic group including a bonded functional group is bonded to the main chain.

1. Potential ion conducting polymer

The potential ion conductive polymers according to the present invention provide a potential ion conductive polymer comprising a potential ion conductive substituent as a pendant substituent substituted on the main chain forming the polymer.

In the potential ion conductive polymer according to the present invention, the polymer forming the main chain is not particularly limited.

In one embodiment, the polymer forming the main chain may be an olefin polymer, an acrylic polymer, an acetate polymer, a styrene polymer, an ester polymer, an amide polymer, a fluorine or partial fluorine polymer, a cellulosic polymer, , A carbonate-based polymer, a polyimide-based polymer, a polyetheretherketone (PEEK), a polysulfone-based polymer, and the like.

In the above, the olefinic polymer may be, for example, polyethylene (PE), polypropylene (PP), polymethylpentene (PMP), polybutene-1 (PB-1), polyisobutylene Rubber (EPR), ethylene-propylene-diene rubber (EPDM), and C5 to C20 alpha-olefin polymers or copolymers thereof.

In the above, the acrylic polymer may include, for example, one or two or more monomers selected from the group including (meth) acrylic acid, C1 to C10 (meth) acrylates, C1 to C10 (meth) acrylamides and acrylonitrile But is not limited thereto.

In the above, the acetate-based polymer may be, for example, polyvinyl acetate (PVAc), polyvinyl alcohol (PVA), ethylene-vinyl acetate copolymer (EVA), vinyl acetate-acrylic acid copolymer (VA / AA) Acetate (PVCA), and polyvinylpyrrolidone (Vp / Va copolymer).

The styrene-based polymer may be, for example, a polystyrene, an acrylonitrile-styrene-butadiene copolymer, a styrene-butadiene copolymer (rubber or latex), a styrene-isoprene-styrene copolymer, / Butadiene-styrene copolymer, a styrene-divinylbenzene copolymer, or a styrene-acrylonitrile copolymer.

In the above, the ester polymer may be, for example, polyethylene terephthalate, polybutylene terephthalate, polylactic acid, polycaprolactone, polyhydroxybutyrate, polybutylene succinate, polyethylene naphthalate or polyethylene adipate , But is not limited thereto.

In the above, the amide polymer may be, for example, nylon 4, nylon-6, nylon-66, nylon 12 or copolymers thereof, but is not limited thereto.

In the above, the fluorinated or partially fluorinated polymer may be, for example, polyvinylidenefluoride (PVDF), polytrifluoroethylene (TrFE), polytetrafluoroethylene (PTFE), polyhexafluoropropylene (polyhexafluoropopylene, PHFP), or copolymers of two or more thereof, but is not limited thereto.

In the above, the cellulosic polymer may be selected from the group consisting of, for example, cellulose, nitrocellulose, carboxymethylcellulose and cellulose acetate, but is not limited thereto.

The polyimide-based polymer is, for example, polyimide, polyamideimide and the like, but is not limited thereto.

In the above, the glycol-based polymer may be, for example, polyethylene glycol, polypropylene glycol, polybutylene glycol, or a copolymer thereof, but is not limited thereto.

In the above, the polysulfone-based polymer may be selected from the group consisting of polysulfone (PSF or PSU), poly (ether sulfone), PES, polyphenylsulfone (PPSU or PPSF) (Arylene ether sulfone), and the like, but are not limited thereto.

In the present invention, the potential ion conductive polymer may be an oligomer or a macromer. In one embodiment, the oligomer includes, for example, a small number of polymerized units wherein the polymerized units forming the main chain in the polymer are 100 or less, 50 or less, or 20 or less, or 10 or less . In one embodiment, the macromer may comprise greater than 10, greater than 20, greater than 50, or greater than 100 polymerized units.

In one embodiment, the polymer forming the main chain may be a linear polymer and may be a branched geometry such as, for example, star or comb, Or a branched polymer.

On the other hand, in terms of composition, the polymer forming the main chain may be a homopolymer or a polymer containing two or more polymerized units in the form of random- or block-copolymerization. The block-copolymer may be, for example, a di-block, a tri-block or a more copolymer.

Non-limiting examples of polymers forming the main chain include the following forms (1) to (5):

(One)

(2)

(3)

(4)

(5)

In the above, A, B and C are repeating units of the polymer, and B and C may be the same or different.

In one embodiment, the repeating units A, B, or C in the polymers of Forms (2) to (5) described above may be chemically and physically the same or completely different. For example, the repeating unit A is hydrophilic and the repeating unit B or C is hydrophobic. For example, when the melt is cooled or the polymer in solution is dried, the self-assembly phenomenon or phase separation phenomenon occurs due to the difference in compatibility .

A potential ion conductive polymer according to the present invention is one that contains a potential ion conductive substituent as a pendant substituent substituted in a polymer forming the main chain described above.

In the present invention, the potential ionically conductive substituent is a substituent whose ion-conducting functional group is protected by a protecting group.

In one embodiment, the ion conductive functional group may be used singly or in combination of two or more, such as a sulfonic group, a carboxyl group, an acrylic acid group, or a phosphoric acid group. The ion conductive functional group may be in the form of an acid such as a sulfonic group, a carboxyl group, an acrylic acid group or a phosphoric acid group, or in the form of an alkali metal salt, an alkaline earth metal salt, or a transition metal salt thereof.

In one embodiment, the protecting group is a C3 to C10 alkyl group. In a preferred embodiment, the alkyl group is a C4-C10 alkyl group in the tert- or neo-branched form. In a more preferred embodiment, the alkyl group is a tert-butyl, tert-pentyl or neopentyl group.

In a more preferred embodiment, the pendant substituent is a substituent represented by the following formula 1-1, 1-2 or 1-3:

[Formula 1-1] [Formula 1-2] [Formula 1-3]

Wherein R and R 'are each independently a C3 to C10 alkyl group, preferably a tert-or neo-branched C4 to C10 alkyl group.

In potential ion conductive polymers according to the invention, it is preferred that the potential ionically conductive substituents as pendant substituents substituted on the main chain are present in a molar ratio of 1: 1 per functional group.

The potential ion conductive polymer is not protected by a protecting group and is compatible with various organic solvents as opposed to a polymer containing a sulfonic group, a carboxyl group, an acrylic acid group or a phosphoric acid group. For example, the polymer may be dissolved in a solvent such as chloroform, tetrahydrofuran, chlorobenzene, and bromobenzene.

In a preferred embodiment, the potential ion conductive polymer comprises a polymeric unit represented by the following formula (2)

(2)

Wherein n is an integer from 1 to 200 and R is a protecting group.

The potential ion conductive polymer can be converted into a polymer having an ionic portion by deprotection treatment. The deprotection treatment is, for example, heat treatment; Chemical treatments such as acids and bases; Or a light treatment such as visible light, UV- or electron beam irradiation. These treatments can be used in combination.

As a non-limiting example, the poly (alkyl p-styrene sulfonate) compound represented by the following general formula (2) is deprotected when heat treatment is performed at a temperature of, for example, (P-styrene sulfonic acid). ≪ / RTI > In addition, the compound of formula (2-1) can be reacted with a base, for example NaOH. KOH, Na ₂ CO ₃ or the like to obtain metal salts of poly (p-styrenesulfonic acid) represented by the formula (2-2).

[Chemical Formula 2] [Chemical Formula 2-1] [Chemical Formula 2-2]

Wherein n is an integer from 5 to 200, R is a protecting group, and M is an alkali metal, an alkylittal metal, or a transition metal.

In the above, Formulas (2-1) and (2-2) are "ionic polymers having an ionic compound in the repeating unit". Therefore, it has ionic conductivity, particularly hydrogen ion conductivity. Therefore, when it is formed into a dispersed phase, it has an ion channel function.

The ion conductive polymer according to the present invention may be a polymer comprising two or more polymerized units wherein the pendant substituents with potential ionic conductivity may be evenly distributed throughout the copolymer or may be localized to either polymer unit have. In this case, the substituent having no pendant substituent can be selected in consideration of compatibility when blended with other polymer.

For example, when the pendant substituent having potential ion conductivity is localized in any one of the two or more polymerized units, the ion conductive polymer may be a polymeric unit represented by Formula 2 and a nonionic polymeric copolymer, The nonionic polymer may be at least one selected from the group consisting of an olefin polymer, an acrylic polymer, an acetate polymer, a styrene polymer, an ester polymer, an amide polymer, a fluorine or partial fluorine polymer, a cellulosic polymer, a glycol polymer, A polyether ether ketone (PEEK), a polysulfone-based polymer, and the like, but are not limited thereto.

In a preferred embodiment, the polymer having the potential ionic conductivity represented by the following formula (3) may be a block copolymer of a latent ion conductive polymer and a non-ionic acrylic polymer.

(3)

N is an integer of 1 to 200, R is a protecting group, m is an integer of 10 to 1,000, R ₁ is a straight or branched alkyl of C1-C10, and R ₂ is hydrogen or methyl.

In a more preferred embodiment, R ₁ and R ₂ are each methyl. In this case, the acrylic polymer is polymethylmethacrylate (PMMA). In another embodiment, R < ₁ > is methyl and R < ₂ > In this case, the acrylic polymer is polymethylacrylate (PMA).

In the above-mentioned block copolymer, the acrylic polymer block is a neutral nonpolar polymer. In addition, it is relatively non-polar compared to the polymer comprising the above-mentioned poly (alkyl p-styrene sulfonate). The non-polar portion is introduced to improve the compatibility with the second polymer, which will be described later.

In one embodiment of the composition, the content ratio of the potential ion conductive polymer and the non-polar acrylic polymer contained in the block copolymer may be 30 to 80% by weight, preferably 50 to 70% by weight. For example, if the content of the potential ion conductive polymer contained in the block copolymer is less than 30% by weight, there is a problem that the ion conductive property is low after forming a complex with the fluorinated polymer. When the content exceeds 80% by weight, a complex with the fluorinated polymer It may be difficult to form a homogeneous complex when it is formed.

2. Resin composition

In the present invention, a first polymer containing a potential ion conductive polymer; And a second polymer comprising an emissive resin for the potential ion conductive polymer.

In one embodiment of the composition of the present invention, the potential ion conductive polymer included in the first polymer is a potential ion conductive polymer containing a potential ion conductive substituent as a pendant substituent substituted on the main chain forming the polymer, As shown above.

On the other hand, the second polymer is nonionic and may be any of olefin polymers, acrylic polymers, acetate polymers, styrene polymers, ester polymers, amide polymers, fluorinated or partially fluorinated polymers, A polyimide-based polymer, a polyether ether ketone (PEEK), a polysulfone-based polymer, and the like. Concrete examples of the polymers exemplified are the same as those listed in the polymers forming the main chain of the ion conductive polymer.

One criterion for selecting the second polymer to be blended with the first polymer is their compatibility. For example, when a resin that is incompatible with the first polymer as the second polymer is selected, it is possible to induce phase separation after blending, for example, in a molten state or in a solution state.

In a preferred embodiment, the second polymer is a fluorine-based or partially fluorine-based polymer. The fluorine-based polymer may be, for example, polytetrafluoroethylene (PTFE), polyhexafluoropopylene (PHFP), or the like. The partially fluorinated polymer is, for example, polyvinylidenefluoride (PVDF) or polytrifluoroethylene (TrFE). The fluoropolymer and the partial fluoropolymer may be copolymers in which two or more components are copolymerized. Examples of the copolymer applicable to the present invention include polyvinylidene-trifluoroethylene (PVDF-TrFE) tetrafluoroethylene-co-hexafluoropropylene, tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride Ternary copolymers and the like. The fluorine-containing or partially fluorine-containing polymer can be used by purchasing a commercially available product. Examples of commercially available products include Aciplex (Asahi Chemical), Flemion (Asahi Glass), and the like.

When the fluorine-based or partially fluorine-based polymer is selected as the second polymer, the potential ion-conductive polymer is relatively non-compatible with the fluorine-based or partially fluorine-based polymer, but is relatively less soluble than the polymer having the sulfonic acid or sulfonate- . Therefore, when a film is cast using a composition comprising a first polymer and a second polymer, and phase separation is induced through a self-assembly process, the size of a domain formed as a dispersed phase can be stably controlled.

In one embodiment, the fluorinated or partially fluorinated polymer may have a weight average molecular weight of 1,000 to 100,000. The molecular weight control of the fluorinated or partially fluorinated polymers can be another means of controlling the morphology of the ion conductive membrane.

In one embodiment, the weight ratio of the first polymer to the second polymer may be 30:70 to 60:40, preferably 40:60 to 50:50. If the content of the first polymer is less than 30% by weight, the ion conductive property is low. If the content of the first polymer exceeds 60% by weight, the ion conductive material may be discharged to the electrolyte.

Each of the components of the composition according to the present invention, for example, the poly (alkyl p-styrene sulfonate) constituting the first polymer and the fluoropolymer or the partial fluoropolymer constituting the acrylic polymer and the second polymer resin, , The acrylic polymer constituting the first polymer is excellent in compatibility with the fluorine-based or partially fluorine-based polymer. Accordingly, when the composition is cast and then self-assembly is induced, the phase separation is performed such that the poly (alkyl p-styrene sulfonate) block forms one phase, and the acrylic polymer block of the first polymer and the second polymer , It is possible to induce self-assembly.

3 . Method for manufacturing ion conductive membrane

The present invention also provides a method for preparing an ion conductive membrane using the above-mentioned composition. A method of manufacturing an ion conductive membrane according to the present invention includes the steps of casting a polymer resin composition comprising a first polymer containing a potential ion conductive polymer and a second polymer including a potential ion conductive polymer and a resin incompatible with the ion conductive polymer; And, after the casting, inducing self-assembly of the potentially ion conductive polymer block to obtain a film precursor film; And converting the self-assembled potential ion conductive polymer into an ion conductive polymer to form an ion channel.

In the first step of the above production method, the respective components of the polymer resin composition comprising the first polymer and the second polymer are as described above.

In one embodiment of the manufacturing method, the casting is performed by dissolving or suspending each component of the resin composition in an appropriate solvent, or applying the solution or suspension to glass or a film which is not known in the art, such as a Teflon film Followed by drying. In another embodiment, the casting may be formed directly on the electrode, such as, for example, an electrode of a fuel cell. The application may be carried out according to techniques known in the art, such as bar coating, spray coating, slit coating or brush coating.

One advantage of the compositions and processes of the present invention is that the choice of solvent used to dissolve or suspend the composition in this step is free. For example, when self-assembly is induced by blending an ionic polymer and a non-ionic polymer for the purpose of forming an ion channel, there are limitations in selecting a co-solvent that solves these problems due to the difference in polarity. Aggregation of polar molecules is liable to occur even when it is selectively dissolved, so that it is difficult to control the morphology. In the case of the present invention, the polymer or polymer block with potential ionic conductivity is neutral similar to the second polymer. Therefore, the co-solvent selection can be made wide, and further, the coagulation can be prevented, and the morphology after the self-assembly induced in the following steps is stable.

In the second step, the casting film is dried and self-assembly is induced to obtain a film precursor film. The self-assembly of this step determines the morphology of the ionic channels present in the film precursor film, and ultimately, in the ion conductive membrane to be produced.

Drying of the casting film for self-assembly is known in the art, and any method can be adopted as long as it can induce self-assembly. In one embodiment, the drying may be natural drying at room temperature (25 占 폚). Natural drying is advantageous for the self-assembly of polymer blocks with potential ionic conductivity because the migration of polymer blocks or microstructures can be carried out with some solvents dissolved. In another embodiment, the drying may be carried out in a warm state above normal temperature. The temperature and time of the heating can be appropriately selected in consideration of the boiling point of the solvent or the self-assembly time.

In one embodiment, additional drying may be carried out under reduced pressure conditions after self-assembly is complete, if necessary to clear the film precursor film.

FIG. 1 is a schematic view of a film precursor film in which morphology is controlled by inducing self-assembly in the second step. FIG. Referring to FIG. 1, the blue region is a block self-assembled with a potential ion conductive polymer block included in the first polymer and a yellow region is a second polymer that is incompatible with the potential ion conductive polymer, Is a region formed by a mixture of the polymer and the acrylic polymer block in the first polymer.

The result of self-assembly typically involves phase separation. In the present invention, the form of separation is not necessarily the same as that shown in Fig. 1, but may be a cylindrical shape passing through the upper and lower portions of the membrane, a sea-island shape, a layered shape, or the like.

One of the features of the method of the present invention is that the potential ion conductive polymer block included in the first polymer (for example, the polymer represented by the formula (2) is a polymer having a form such as a sulfonic acid or a sulfonate in terms of compatibility (2-1) and (2-2), the compatibility with the second polymer resin is good, and the difference in compatibility is easy to control the microstructure morphology induced by self-assembly .

In the final step of the method of the present invention, the self-assembled potential ion conductive polymer is converted into an ion conductive polymer to form an ion channel. Referring again to FIG. 1, the morphology of the microstructure at this stage does not change or remains at a level that is small compared to the change due to the self-assembly of the previous stage, and the potential ion conductive polymer is a polar ion- Only its chemical properties change.

The conversion is such that the conversion is deprotection of a functional group protected by a protecting group, for example, a sulfonic group, a carboxyl group, an acrylic group or a phosphoric acid group protected by a protecting group.

In one embodiment, the heating is carried out at a temperature of at least 100 ° C, preferably at least 120 ° C, most preferably at least 150 ° C. When heating is carried out, it is possible to reduce the thermal decomposition phenomenon which may be caused by the heating furnace by heating in a nitrogen or vacuum state. The heating time may vary depending on the content of the protecting group and can be, for example, 60 to 200 minutes. Heating for 60 minutes or less may not allow removal of the protecting group, and pyrolysis may occur for more than 200 minutes. Heating is carried out according to methods known in the art. For example, a known heating means such as an oven or a heater can be used, but the present invention is not limited thereto. However, the heating is preferably carried out at a temperature not exceeding 200 캜, preferably 180 캜. In case of heating at a temperature of 200 占 폚 or more for a long time, undesirable side reactions such as oxidation and discoloration of the polymer material may be involved.

By the heating, the protecting group of the potential ion conductive polymer is separated and separated from the constituting resin while the microstructure morphology of the film precursor film is maintained, and thereby the polar ion conductive polymer resin is converted. The ion conductive polymer resin of the polarity formed may be provided as an ion conductive channel, for example, as an electrolyte membrane of a fuel cell. The microstructure maintains that of the film precursor film.

According to the manufacturing method of the present invention, an ion conductive film having an ion conductive channel formed of an ion conductive block in a matrix formed of a second polymer resin or a non-polar acrylic polymer of a second polymer resin and a first polymer resin is produced .

In one embodiment, the thickness of the ion conductive film can be arbitrarily adjusted as needed. For example, the ion conductive membrane manufactured according to the present invention can be used as an electrolyte membrane for a fuel cell. In this case, the electrolyte membrane is 50 m or less, and in a specific embodiment is 40 m or less, 30 m or less, .

In one embodiment, the water absorption rate of the ion conductive membrane is 15 to 25% by weight; The ionic conductivity can be 10 < ^-1 > S / cm or more.

Illustratively, when the membrane is used as an ion conductive electrolyte membrane, the morphology of the ion conductive channel is one of the factors determining the required physical properties as an electrolyte membrane, for example, water absorption rate or hydrogen ion conductivity. According to the manufacturing method of the present invention, the morphology of the ion conductive channel can be easily controlled.

Hereinafter, the present invention will be described in more detail with reference to examples. The following examples serve to illustrate the present invention and are not intended to limit the scope of the present invention.

Poly (neopentylstyrenesulfonate) (PNSS) was synthesized according to Synthesis Route 1 below.

[Synthetic route 1]

The above block copolymers were prepared according to Synthesis Route 1 using an atom transfer radical polymerization (ATRP) polymerization method, which is one of the living radical polymerization methods. A 50 mL flask was charged with CuBr EBOS (0.3 mmol, 0.43 mmol) diluted in toluene at 700 mM was added to a solution of the title compound (0.3 mmol, 43.0 mg), enisole (10 mL), PMDETA (0.3 mmol, 51.9 mg) mL, toluene) was poured while flowing Ar gas. After stirring for 10 minutes, the mixture was placed in a prepared 80 ° C oil bath, and the reaction was allowed to proceed for 14 hours and then the temperature was dropped to -78 ° C to stop the reaction. The reaction solution was diluted with 10 mL of THF solvent, and the solution was passed through a column tube filled with aluminum oxide to remove the metal catalyst. The reaction solution was poured into 200 mL of hexane to obtain a white precipitate, which was dried in vacuo at room temperature for 2 days Lt; / RTI >

For the synthesis of MMA-b-PNSS copolymer, a 50 mL flask was charged with CuCl ₁ (0.3 mmol, 29.7 mg), Enisole (10 mL), dNbpy (0.6 mmol, 0.24 g), PNSS I poured it in. After stirring for 10 minutes, the mixture was placed in a prepared 80 ° C oil bath, and the reaction was allowed to proceed for 24 hours and then the temperature was dropped to -78 ° C to stop the reaction. The reaction solution was diluted with 10 mL of a THF solvent. The solution was passed through a column tube filled with aluminum oxide to remove the metal catalyst, and a PNSS-PMMA block copolymer solution was poured into 200 mL of hexane to obtain a white precipitate , Followed by vacuum drying at room temperature for 2 days.

The molecular weight and the weight fraction of each block of the PNSS-PMMA block copolymer obtained through the above experiment can be controlled by adjusting the ratio of the monomer NSS and the MMA and controlling the reaction time under the above reaction conditions.

FIG. 2A shows the results of GPC analysis of molecular weights and molecular weight distributions for the PNSSs synthesized in the examples, and FIG. 2B is a comparison of results of GPC analysis of PNSS and PNSS-PMMA molecular weights and molecular weight distributions. From FIG. 2A, the molecular weight and molecular weight distribution of PNNS were shown in terms of [NSS] / [2-EBP] / [CuBr] / [PMDETA] = (60/1/1/1) When the time was increased from 3 hours to 21 hours, the monomer conversion tended to increase from 21% to 84%, and the molecular weight tended to increase from 2,800 g / mol to 7,500 g / mol. In the experimental results, the parts indicated by the arrows are due to the coupling between the chains, which must be avoided for copolymerization. For this reason, it is preferable to set the NSS conversion rate to 50% or less for copolymerization.

FIG. 2B shows the results of GPC analysis of MMA-b-NSS obtained by reacting at a ratio of [MMA] / [PNSS] / [CuCl] / [dNbpy] = (80/1/1/2) to be. The molecular weight of the obtained PNSS-PMMA was increased from 9,400 g / mol to 15,000 g / mol by the GPC graph.

FIG. 3A is a ¹ H NMR spectrum of PNSS having a molecular weight Mn of 9,400 g / mol and PNSS-PMMA having a Mn of 15,000 g / mol. In FIG. 3A, the chemical structure of PNSS and PNSS-PMMA can be confirmed by ¹ H NMR spectra and it can be confirmed that the PNSS-PMMA block copolymer is synthesized well. Also, the weight fraction of each block of PNSS-PMMA can be calculated, where the weight fraction of calculated PNSS is 70% by weight.

2. Blending with fluorinated polymers, film casting, and annealing

To the THF solvent, 0.3 g of the prepared PNSS-PMMA and 0.7 g of PVDF-TrFE were dissolved so that the concentration of the premix was 10% by weight. Stirring was carried out for one day for smooth dissolution. The solution was poured onto a glass substrate after filtering using a syringe filter. The prepared solution was dried at room temperature (25 ° C) for 2 days and then dried in a vacuum oven at room temperature for 1 day to completely remove THF to obtain a self-assembled film precursor film.

3B is an IR-spectrum of PNSS-PMMA, PVDF-TrFE, and a complex of the two preceding materials (PNM-PDFE). The intrinsic functional groups of the PNSS-PMMA block copolymer and the PVDF-TrFE can be identified through IR spectra in FIG. 3B. In particular, the peak observed at 1730 cm ^-1 is the peak appearing in the carboxyl functional group of the PNSS- It can be confirmed that PVDF-TrFE contains PNSS-PMMA block copolymer by confirming the peak from the carboxyl functional group in the IR spectrum obtained after the compounding at the ratio of -TrFE and PNSS-PMMA: PVDF-TrFE = 30:70 , in particular a carboxylic acid functional group at the peak of the 1730 1720cm found in a composite material of two materials PNM_PDFE ^- can be moved by a group of PMMA in ^1-PNSS PMMA check having a PVDF-TrFE and compatible with each other.

3. Preparation of ion conductive membrane by heating

Finally, the prepared membrane precursor film was heated at 150 캜 for 80 hours to remove the neopentyl group of neopentylstyrene sulfonate and converted into a styrene sulfonic acid group, thereby preparing an ion conductive membrane.

4 is a graph showing the change in weight with time while the film precursor film is heat-treated. From FIG. 4, it was confirmed that when the heat treatment was performed at a constant temperature of 150 ° C, the neopentyl group was reduced by about 5% per hour at the beginning, and no further decrease in weight was observed after about 60 hours.

5 is an ATM phase photograph of the self-assembled film precursor film after annealing is completed and the surface of the ion conductive membrane where the ion channel is formed after the heat treatment is completed. From Fig. 5, it is possible to confirm the structural change of the surface before and after heating at the aforementioned 150 ° C under vacuum condition for 12 hours. It can be confirmed that the size of the domain including the styrene sulfonic acid group which serves as an ion conduction channel is enlarged although the overall structure is maintained before and after heating. This phenomenon is a phenomenon in which the repulsive force with the PVDF-TrFE applied as a matrix by the styrene sulfonic acid group having an ionic group becomes large, and the domain formation between the PSPSs containing the styrene sulfonic acid group is activated.

FIG. 6 is a graph recording the water absorption rate of the ion conductive film manufactured over time. The water absorption capacity was measured by immersing the prepared membrane in ultra-pure water at room temperature, measuring the weight with increasing time, and calculating "(weight of membrane after swelling-weight of membrane before swelling) / (weight of membrane before swelling)".

In the examples, PVDF-TrFE showed no change in weight with time but PSM_PDFE (PNSS-PMMA: PVDF-TrFE = 30:70) complex in which a styrene sulfonic acid group was introduced into a composite of a PNSS-PMMA block copolymer and PVDF- , The weight increased by 11% in 5 minutes and slowly increased after that, but the weight did not change after 45 minutes. As a result, it was confirmed that the PSM_PDFE composite can contain 15 wt% of ultrapure water.

FIG. 7 is a graph showing the hydrogen ion conductivity of the ion conductive membrane prepared according to the method of the present invention. The quadrupole electrode structure for measuring hydrogen ion conductivity can control the constant temperature and constant humidity connected to an electrochemical interface (Solatron 1287, Solatron Analytical, Farnborough Hampshire, GU14, ONR, UK) and an impedance phase analyzer (Solatron 1260) , Which measures the ohmic resistance using the Nyquist line and the Bode line.

In the table, the black (- - -) indicates the hydrogen ion conductivity of the PSM-PDFE membrane, while the red (- • -) indicates the hydrogen ion conductivity of the PNM-PDGE membrane will be. From the above table, it can be confirmed that the ion conductive membrane according to the present invention is not only superior in ion conductivity but also superior to commercially available Nafion products as compared with the control group.

Claims (22)

Casting a first polymer, which is a copolymer of a potential ion conductive polymer and a non-ionic polymer, and a polymeric resin composition comprising the potential ion conductive polymer and a non-compatible polyvinylidene fluoride (PVDF);
After the casting, inducing self-assembly of the potentially ion conductive polymer block to obtain a film precursor film; And
And converting the self-assembled potential ion conductive polymer into an ion conductive polymer to form an ion channel,
Wherein the self-assembling is such that the potential ion conductive polymer block forms one phase, and the non-ionic polymer block of the first polymer and the polyvinylidene fluoride form one remaining phase.
The ion conductive membrane according to claim 1, wherein the ion conductive membrane is formed by forming a matrix of polyvinylidene fluoride or polyvinylidene fluoride and a nonionic polymer block of the first polymer; Wherein the ionic polymeric resin formed by converting the potential ion conductive polymer of the first polymer forms an ion channel.
3. The method of claim 1, wherein the potential ionically conductive polymer comprises a potential ionically conductive substituent as a pendant substituent substituted on the main chain that forms the polymer. 4. The method according to claim 3, wherein the potential ion conductive substituent is one in which an ion-conductive portion of the ion conductive functional group is protected by a protecting group.
5. The method according to claim 4, wherein the ion conductive functional group is at least one selected from the group consisting of a sulfonic group, a carboxyl group, an acrylic acid group and a phosphoric acid group.
5. The method of claim 4, wherein the protecting group is a C3 to C10 alkyl group.
The process according to claim 4, wherein the protecting group is tert-butyl, tert-pentyl or neopentyl.
4. The polymer composition according to claim 3, wherein the main chain forming polymer is at least one selected from the group consisting of an olefin polymer, an acrylic polymer, an acetate polymer, a styrene polymer, an ester polymer, an amide polymer, a fluorinated or partially fluorinated polymer, a cellulosic polymer, Wherein the polymer is at least one selected from the group consisting of an ethylene-based polymer, an ethylene-based polymer, a polyimide-based polymer, a polyetheretherketone (PEEK), and a polysulfone-based polymer.
4. The method according to claim 3, wherein the potential ion conductive substituent is a substituent represented by the following formula (1-1), (1-2) or (1-3)
[Formula 1-1] [Formula 1-2] [Formula 1-3]

Wherein R and R 'are each independently a C3 to C10 alkyl group.
4. The method according to claim 3, wherein the polymer comprises a unit represented by the following formula (2):
(2)

Wherein n is an integer from 1 to 200 and R is a protecting group.
4. The method according to claim 3, wherein the polymer is a block copolymer of a potential ion conductive polymer and an acrylic polymer represented by the following formula (3)
(3)

N is an integer of 1 to 200, R is a protecting group, m is an integer of 10 to 1,000, R ₁ is a straight or branched alkyl of C1-C10, and R ₂ is hydrogen or methyl.
delete delete delete delete delete The method according to claim 1, wherein the weight ratio of the first polymer to the polyvinylidene fluoride in the composition is from 30:70 to 60:40.
delete delete delete An ion conductive membrane produced by the method of claim 1, wherein an ion channel of the polar polymer resin is formed in the polyvinylidene fluoride matrix.
22. The composition of claim 21, wherein the water absorption rate is from 15 to 25% by weight; Wherein the ionic conductivity is 10 < ^-1 > S / cm or more.

Images