Novel polymer and anion exchange membrane containing the same

Abstract

The present invention provides a novel polymer and an anion exchange membrane containing the same, which has improved ionic conductivity and durability.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0176765, dated December 16, 2022, and all contents disclosed in the documents of that Korean patent application are incorporated herein by reference.

[0002] The present invention provides a novel polymer and an anion exchange membrane containing the same, which has improved ionic conductivity and durability. [Background technology]

[0003] An anion exchange membrane is a membrane that has ionic groups with a positive charge, and is able to selectively allow only anions to pass through, while cations have difficulty passing through due to repulsion between the same charges.

[0004] Alkaline electrolysis cells (AECs) using such anion exchange membranes can use low-cost metals such as nickel and manganese as electrode catalysts instead of the precious metal platinum, which makes them inexpensive. This allows them to overcome the disadvantages of existing commercial cation exchange membranes (high cost and fuel crossover, etc.), and they can be widely used in electrochemical devices such as fuel cells, water electrolyzers, and redox flow batteries.

[0005] However, current anion exchange membranes have lower ionic conductivity than cation exchange membranes, and there are difficulties in commercializing them due to chemical / mechanical stability issues under basic conditions. Therefore, in order to develop AEC water electrolyzers to ensure competitiveness in hydrogen production, technology is needed to manufacture high-performance, highly durable anion exchange membranes at a lower cost than existing technologies.

[0006] Therefore, there is a continuing demand for the development of anion exchange membranes that are price competitive and have improved ion conductivity and durability. Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, the present invention provides a novel polymer, a method for producing the same, an anion exchange membrane containing the novel polymer and having improved ion conductivity and durability, and a method for producing the anion exchange membrane. [Means for solving the problem]

[0008] According to one embodiment of the present invention, A polymer containing a crosslinked structure represented by the following chemical formula 1 is provided. [ka]

[0009] In the above Chemical Formula 1, R1 and R2 are each independently a halogen or C 1-4 is alkyl, a and b are each independently an integer from 0 to 3; R3 and R4 are each independently hydrogen or C 1-4 is alkyl, R5 is C 1-10 is alkyl, R6 to R9 are each independently C 1-4 is alkyl, L is C 1-10 is alkylene, Q is a halogen; n is an integer from 1 to 3, x, y and z represent the mole fraction of each repeating unit in the polymer.

[0010] According to yet another embodiment of the present invention, Step 1: reacting a first polymer, which is an ABC triple block copolymer represented by the following chemical formula 1-1, with hydrogen halide to prepare a second polymer, which is an A-B'-C triple block copolymer represented by the following chemical formula 1-2: Step 2: reacting a second polymer represented by the following formula 1-2 with an alkene represented by the following formula 1a to produce a third polymer, which is an A-B''-C triple block copolymer represented by the following formula 1-3; and and (3) reacting a third polymer represented by the following chemical formula 1-3 with a diamine represented by the following chemical formula 1b to produce a polymer having a crosslinked structure represented by the following chemical formula 1: The present invention provides a method for producing a polymer having a crosslinked structure represented by Chemical Formula 1. [ka] [ka] In the above chemical formulas 1-1 to 1-3, 1a and 1b, R1 to R9, L, Q, a, b, n, x, y, and z are as defined in Chemical Formula 1 above.

[0011] According to yet another embodiment, there is provided an anion exchange membrane comprising the polymer described above.

[0012] According to another embodiment, Step 1: reacting the third polymer represented by Chemical Formula 1-3 with the diamine represented by Chemical Formula 1b in an organic solvent to prepare a polymer solution containing a crosslinked structure represented by Chemical Formula 1; and and (step 2) casting the polymer solution onto a substrate and then drying the cast film. A method for producing an anion exchange membrane is provided. [Effects of the Invention]

[0013] The novel polymer of the present invention uses a styrene-isoprene-styrene triple block copolymer, which has the advantages of a simple synthesis process and low processing costs, thereby reducing manufacturing costs. The distance between the ionic bond and the main chain can then be increased through atom transfer radical polymerization of the copolymer, thereby improving the ionic conductivity of an anion exchange membrane containing the copolymer. Furthermore, the formation of several tens of nanostructures allows for microphase separation, facilitating ion migration through nanochannels. Furthermore, the polymer has superior mechanical strength compared to a single polymer, thereby improving the durability of an anion exchange membrane containing the polymer. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a photograph of the anion exchange membrane produced in Example 1. [Figure 2] 1 shows the 1H NMR analysis spectra of the second polymer (SIS-Cl) and the third polymer (SIS-hex-Cl) produced in Example 1. [Figure 3] 1 shows the 1H NMR analysis spectrum of the first polymer (SIS), which is the starting material of Example 1. [Figure 4] 1 shows FT-IR analytical spectra of the first polymer (SIS), which is the starting material in Example 1, and the second polymer (SIS-Cl), third polymer (SIS-hex-Cl), and anion exchange membrane (X1-SIS-hex-QA) produced in Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0015] The terms used in this specification are merely used to describe exemplary embodiments and are not intended to limit the invention. The singular expressions include the plural expressions unless the context clearly dictates otherwise. It should be understood that the terms "comprise," "comprise," "have," and the like, as used in this specification, are intended to specify the presence of implemented features, steps, components, or combinations thereof, and do not preclude the presence or additional possibility of one or more other features, steps, components, or combinations thereof.

[0016] Furthermore, in the present invention, when a layer or element is referred to as being formed "on" another layer or element, it means that the layer or element is formed directly on the other layer or element, or that other layers or elements may be additionally formed between the layers, on the object, or on the substrate.

[0017] Since the present invention can be modified in various ways and can have various forms, specific examples are exemplified and described in detail below, but it is not intended to limit the invention to the particular disclosed form, and it should be understood that the invention includes any modifications, equivalents, or alternatives falling within the spirit and technical scope of the invention.

[0018] Furthermore, the terminology used herein is for the purpose of referring to particular embodiments only and is not intended to limit the present invention, and the singular forms used herein also include the plural forms unless the context clearly dictates otherwise.

[0019] Meanwhile, the term "polymer" as used herein refers to a compound produced by polymerizing a monomer compound, and includes both homopolymers and copolymers.

[0020] Furthermore, in this specification, the alkyl group may be linear or branched, and the number of carbon atoms is not particularly limited, but is preferably 1 to 10. According to yet another embodiment, the number of carbon atoms in the alkyl group is 1 to 6. According to yet another embodiment, the number of carbon atoms in the alkyl group is 1 to 4. Specific examples of the alkyl group include methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methylbutyl, 1-ethylbutyl, pentyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, 1-ethylpropyl, 1,1-dimethylpropyl, hexyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, and 2-ethylbutyl. Examples of cyclohexyl include, but are not limited to, cyclopentyl, heptyl, n-heptyl, isohexyl, 1-methylhexyl, 2-methylhexyl, 3-methylhexyl, 4-methylhexyl, 5-methylhexyl, cyclopentylmethyl, cyclohexylmethyl, octyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2,4,4-trimethyl-1-pentyl, 2,4,4-trimethyl-2-pentyl, 2-propylpentyl, n-nonyl, and 2,2-dimethylheptyl.

[0021] In this specification, the alkylene group is a divalent group, not a monovalent group, but the same explanation as for the alkyl group can be applied.

[0022] In addition, in this specification, halogen means fluorine, chloro, bromo, or iodo.

[0023] Recently, as demand for fuel cells as a next-generation energy source has increased, interest has been growing in anion exchange membranes to overcome the limitations of cation exchange membrane fuel cells. However, when the degree of crosslinking is increased to improve the durability of anion exchange membranes, such as dimensional stability and alkaline stability, there is a problem that ionic conductivity decreases.

[0024] However, the present inventors have confirmed that by preparing a polymer having halogenated alkyl groups introduced into the side chains by the hydrogen halide reaction and atom transfer radical polymerization reaction of a styrene-isoprene-styrene triple block copolymer, and then crosslinking the polymer with a diamine compound, it is possible to produce an anion exchange membrane that can increase the distance between the ionic bond and the main chain, thereby improving ionic conductivity, and at the same time, can produce an anion exchange membrane that can easily move ions through nanochannels due to the formation of nanostructures with several tens of nanometers, and that has mechanical strength that is much superior to that of a single polymer, thereby improving durability.

[0025] Hereinafter, the novel polymer, the method for producing the same, the anion exchange membrane containing the same, and the method for producing the anion exchange membrane will be described in more detail according to specific embodiments of the invention.

[0026] Polymer and its manufacturing method In one embodiment, there is provided a polymer comprising a crosslinked structure represented by the following Chemical Formula 1: [ka] In the above Chemical Formula 1, R1 and R2 are each independently a halogen or C 1-4 is alkyl, a and b are each independently an integer from 0 to 3; R3 and R4 are each independently hydrogen or C 1-4 is alkyl, R5 is C 1-10 is alkyl, R6 to R9 are each independently C 1-4 is alkyl, L is C 1-10 is alkylene, Q is a halogen; n is an integer from 1 to 3, x, y, and z represent the mole fraction of each repeating unit in the polymer, where x+y+z=1.

[0027] The polymer is an ionomer in which the main chain in the polymer is neutral and the side chains have ionic bonds, and therefore the polymer exhibits ionic conductivity.

[0028] Such a polymer contains a crosslinked structure represented by Chemical Formula 1 and ultimately exhibits the form of a film, and therefore the weight average molecular weight of the polymer can be considered unlimited. However, for example, when the number of crosslinked structures represented by Chemical Formula 1 in the polymer is m, m may be 1 to 100,000,000.

[0029] In addition, the polymer may include not only the crosslinked structure represented by Chemical Formula 1 but also a non-crosslinked structure represented by Chemical Formula 2 below. [ka]

[0030] In other words, the polymer may have a partially crosslinked structure.

[0031] In this case, the crosslinked structure represented by Chemical Formula 1 and the non-crosslinked structure represented by Chemical Formula 2 below may be contained in the polymer in a molar ratio of 1:0.5 to 1:10.

[0032] In addition, in the above Chemical Formula 1, a and b respectively represent the number of R1 and R2, and when a is 2 or more, two or more R1 may be the same or different from each other, and when b is 2 or more, two or more R2 may be the same or different from each other.

[0033] More specifically, R1 and R2 are each independently chloro, bromo, methyl, or tert-butyl; a and b may each independently be 0 or 1.

[0034] At this time, R1 and R2 are identical to each other, a and b may be the same as each other.

[0035] Additionally, R3 and R4 may each independently be hydrogen or methyl.

[0036] For example, R3 may be methyl.

[0037] Also, for example, R4 may be hydrogen.

[0038] Also, R5 is C 1-10 It may also be alkyl.

[0039] For example, R5 can be n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, or n-octyl.

[0040] Preferably, R4 is hydrogen, R5 may be n-pentyl, n-hexyl, n-heptyl, or n-octyl.

[0041] Furthermore, R6 to R9 may all be the same.

[0042] For example, R6 through R9 may all be methyl or ethyl.

[0043] Also, L is C 4-10 It may also be alkylene.

[0044] For example, L can be butylene, pentylene, hexylene, or heptylene.

[0045] Q may also be chloro (Cl).

[0046] In Chemical Formula 1, x, y, and z each represent the moles of the repeating unit in parentheses divided by half the moles of all repeating units in the crosslinked structure represented by Chemical Formula 1, and x + y + z is 1. In addition, x, y, and z each represent the same as the mole fraction of each block in the triple block copolymer used as a starting material for producing a polymer containing a crosslinked structure represented by Chemical Formula 1. Specifically, when the blocks in the triple block copolymer are A, B, and C and the repeating numbers of these blocks are a, b, and c, x can be calculated as a / (a+b+c), y can be calculated as b / (a+b+c), and z can be calculated as C / (a+b+c).

[0047] Specifically, x, y, and z are each independently a real number greater than 0 and less than 1.

[0048] More specifically, x and z may each independently be a real number between 0.01 and 0.5, and y may be a real number between 0.3 and 0.9.

[0049] For example, x may be a real number between 0.1 and 0.25, y may be a real number between 0.5 and 0.8, and z may be a real number between 0.1 and 0.25.

[0050] Furthermore, x+z may be 0.2 to 0.5. More specifically, x+z may be 0.2 or more, 0.21 or more, 0.22 or more, 0.23 or more, or 0.24 or more, and 0.5 or less, 0.45 or less, 0.4 or less, 0.35 or less, 0.3 or less, or 0.25 or less.

[0051] In this case, x and z may be the same.

[0052] More specifically, y may be 0.5 or more, 0.55 or more, 0.6 or more, 0.65 or more, 0.7 or more, or 0.75 or more, and 0.8 or less, 0.79 or less, 0.78 or less, 0.77 or less, or 0.76 or less.

[0053] The polymer may also be derived from a triple block copolymer represented by the following Chemical Formula 1-1, having a weight average molecular weight of 50,000 to 400,000 g / mol. [ka] In the above Chemical Formula 1-1, R1, R2, a, b, x, y, and z are as defined in Chemical Formula 1 above.

[0054] In another embodiment, there is provided a method for preparing a polymer having a crosslinked structure represented by Chemical Formula 1, which is prepared through steps 1 to 3 of Reaction Scheme 1 below. [ka] In the above reaction scheme: R1 to R9, L, Q, a, b, n, x, y, and z are as defined in Chemical Formula 1 above.

[0055] (Step 1) Step 1 is a step of reacting a first polymer, which is an ABC triple block copolymer represented by the above-mentioned chemical formula 1-1, with hydrogen halide (HQ; where Q is a halogen) to produce a second polymer, which is an A-B'-C triple block copolymer represented by the following chemical formula 1-2, and the reaction is a halogenation addition reaction in which hydrogen halide is added to the double bond in the first polymer.

[0056] The first polymer represented by Formula 1-1 is an ABC triple block copolymer prepared by copolymerizing a styrene-based monomer, a C4 conjugated diene-based monomer, and a styrene-based monomer, and has a one-dimensional linear polymer structure in which repeating units are arranged as a long chain. More specifically, in the first polymer, the A block refers to a block represented by the following Formula A, the B block refers to a block represented by the following Formula B, and the C block refers to a block represented by the following Formula C. [ka]

[0057] For example, in consideration of ease of synthesis and manufacturing cost, the first polymer represented by Chemical Formula 1-1 is preferably a styrene-isoprene-styrene triple block copolymer (Styrene-b-Isoprene-b-Styrene; SIS).

[0058] The weight-average molecular weight of the first polymer may be 50,000 to 400,000 g / mol, as described above. The weight-average molecular weight of the triple block copolymer can be measured by gel permeation chromatography (GPC) using a calibration curve generated using polystyrene standards. More specifically, the weight-average molecular weight (Mw, g / mol) of the polymer may be 50,000 or more, 60,000 or more, 70,000 or more, or 80,000 or more, and 400,000 or less, 300,000 or less, 200,000 or less, or 100,000 or less.

[0059] In this step, the hydrogen halide can be used in an amount of 2 to 3 moles per mole of the B block units in the first polymer represented by Chemical Formula 1-1. If the hydrogen halide is used in an excessively low amount, the reaction time may be prolonged, but if the hydrogen halide is used in an excessively large amount, the reaction time remains the same. Therefore, it is preferable to use the hydrogen halide in the above-mentioned range. More specifically, in this step, the hydrogen halide can be used in an amount of 2 moles or more, 2.1 moles or more, 2.2 moles or more, 2.3 moles or more, 2.4 moles or more, or 2.5 moles or more, and 3 moles or less, or 2.95 moles or less, per mole of the B block units in the first polymer represented by Chemical Formula 1-1.

[0060] The reaction may also be carried out in an organic solvent such as toluene, dichloromethane, chloroform, dimethylformamide, dioxane, or tetrahydrofuran, etc. The organic solvent may be used in an amount of 5 to 20 times (mL / g) the volume of the first polymer represented by Formula 1-1, more specifically, 10 to 15 times (mL / g).

[0061] The reaction may be carried out at 20 to 30° C. for 12 to 24 hours. The above range is preferred in terms of reaction rate and production yield.

[0062] (Step 2) Step 2 is a step of reacting the second polymer, which is the A-B'-C triblock copolymer represented by Chemical Formula 1-2, with the alkene represented by Chemical Formula 1a to prepare the third polymer, which is the A-B''-C triblock copolymer represented by Chemical Formula 1-3. The reaction is carried out by atom transfer radical polymerization (ATRP).

[0063] In the second polymer, the A block and the C block are the same as those described above, and the B' block means a block represented by the following chemical formula B'. [ka]

[0064] In the above step, the alkene represented by Formula 1a can be used in an amount of 10 to 100 moles per mole of the B' block unit in the second polymer represented by Formula 1-2. If the alkene is used in an excessively low amount, the durability of the film may be reduced due to the short length of the side chain, while if it is used in an excessively large amount, the reaction may be inhibited. Therefore, it is preferable to use the alkene within the above range. More specifically, in the above step, the alkene represented by Formula 1a can be used in an amount of 10 moles or more, 20 moles or more, 30 moles or more, or 40 moles or more, and 100 moles or less, 90 moles or less, 80 moles or less, 70 moles or less, or 60 moles or less, per mole of the B' block unit in the second polymer represented by Formula 1-2.

[0065] The reaction may also be carried out in an organic solvent such as toluene, dichloromethane, chloroform, dimethylformamide, dioxane, dimethylformamide, or tetrahydrofuran, etc. The organic solvent may be used in an amount of 10 to 30 times (mL / g) of the volume of the second polymer represented by Formula 1-2, more specifically, in an amount of 15 to 20 times (mL / g).

[0066] The reaction may be carried out at 50 to 100° C. for 1 to 72 hours, with the above range being preferred in terms of reaction rate and production yield.

[0067] (Step 3) Step 3 is a step of reacting the third polymer, which is an A-B″-C triple block copolymer represented by Chemical Formula 1-3, with the diamine represented by Chemical Formula 1b to prepare a polymer having a crosslinked structure represented by Chemical Formula 1, and through this reaction, two third polymers represented by Chemical Formula 1-3 are crosslinked by the diamine.

[0068] In the third polymer, the A block and the C block are the same as those described above, and the B″ block means a block represented by the following chemical formula B″. [ka]

[0069] In the above step, the diamine represented by Formula 1b can be used in an amount of 0.1 to 0.3 moles per mole of the B" block units in the third polymer represented by Formula 1-3. If the diamine is used in an excessively low amount, crosslinking may be reduced, resulting in a decrease in the mechanical properties of the membrane. If the diamine is used in an excessively large amount, unreacted diamine may remain, resulting in a decrease in ionic conductivity or a decrease in the physical properties of the membrane. Therefore, it is preferable to use the diamine in the above range. More specifically, in the above step, the diamine represented by Formula 1b can be used in an amount of 0.1 moles or more, 0.11 moles or more, 0.12 moles or more, 0.13 moles or more, or 0.14 moles or more, and 0.3 moles or less, 0.25 moles or less, 0.2 moles or less, 0.19 moles or less, 0.18 moles or less, 0.17 moles or less, or 0.16 moles or less, per mole of the B" block units in the third polymer represented by Formula 1-3.

[0070] The reaction may be carried out in an organic solvent selected from the group consisting of tetrahydrofuran, chloroform, dichloromethane, and toluene, in an amount of 10 to 30 times (mL / g) the volume of the third polymer represented by Chemical Formula 1-3, more specifically, 15 to 25 times (mL / g).

[0071] The reaction may be carried out at 20 to 30° C. with stirring for 1 minute to 3 hours.

[0072] More specifically, after the stirring, the organic solvent may be removed under vacuum at 40 to 80°C for 12 to 24 hours, and then the reaction may be further carried out under vacuum at 80 to 150°C for 24 to 72 hours.

[0073] Anion exchange membrane and method for producing the same Meanwhile, in another embodiment, there is provided an anion exchange membrane including a polymer having a crosslinked structure represented by the above-mentioned Chemical Formula 1.

[0074] In addition, in another embodiment, there is provided a method for producing the above-mentioned anion exchange membrane, which includes the following steps 1 to 3: Step 1 (reacting the third polymer represented by Chemical Formula 1-3 with a diamine represented by Chemical Formula 1b below in an organic solvent to prepare a polymer solution containing a crosslinked structure represented by Chemical Formula 1 below); After casting the polymer solution onto a substrate, the cast film is dried (Step 2).

[0075] (Step 1) Step 1 is a step of crosslinking the third polymer represented by Chemical Formula 1-3 using a diamine compound as a crosslinking agent in an organic solvent, and preparing the third polymer in the form of a polymer solution to facilitate coating for preparing the third polymer into a film.

[0076] In step 1, the organic solvent may be one or more selected from the group consisting of tetrahydrofuran, chloroform, dichloromethane, and toluene, and may be used in an amount of 10 to 30 times (mL / g) the volume of the third polymer represented by Formula 1-3, more specifically, 15 to 25 times (mL / g).

[0077] (Step 2) Step 2 is a step of casting the polymer solution onto a substrate and then drying the cast film. In this step, the polymer solution is applied to a substrate to a certain thickness, and then dried to remove the organic solvent from Step 1, thereby producing a film-type film.

[0078] In this case, the substrate used may be a glass substrate from which the cast anion exchange membrane can be easily released. The polymer solution may be applied to a substrate to a thickness of 20 to 80 μm.

[0079] The drying in step 2 may be performed at 40 to 80° C. for 12 to 24 hours. Specifically, the drying may be performed by vacuum drying, and the organic solvent in step 1 can be completely removed by the drying process.

[0080] Furthermore, after step 2, a heat treatment step may be further performed at 80 to 150° C. for 24 to 72 hours. The heat treatment may be performed in a vacuum, and a crosslinking reaction may further occur through the heat treatment step.

[0081] The anion exchange membrane manufactured by this process may have a thickness of 20 to 80 μm.

[0082] Meanwhile, in another embodiment, a fuel cell including the anion exchange membrane described above is provided.

[0083] In yet another embodiment, there is provided an alkaline electrolysis cell including the anion exchange membrane described above.

[0084] Preferred examples are presented below to aid in understanding the invention, but the following examples are merely for illustrative purposes and are not intended to limit the invention. [Example]

[0085] Example 1: Preparation of a polymer containing a crosslinked structure represented by XL-SIS-hex-Cl and an anion exchange membrane containing the same [ka]

[0086] (Step 1) Hydrochlorination In a 250 mL flask, 5 g of styrene-isoprene-styrene triple block copolymer (Styrene-b-Isoprene-b-Styrene; SIS, the number of blocks in the copolymer is styrene (136), isoprene (838), styrene (136); x = 0.1225, y = 0.7550, z = 0.1225; Mw = 90,000 g / mol) (number of moles of isoprene, which is the B block, in 5 g: 0.04194 mmol) was added as the first polymer, 120 mL of toluene, 120 mL of hydrogen chloride dissolved in acetic acid (pure hydrogen chloride: 3 mL, 0.1226 mmol, 2.923 moles per mole of isoprene), and a magnetic bar were placed, and the reaction was carried out at room temperature for 24 hours. After the reaction was completed, the reaction mixture was precipitated in 5 L of methanol and then reprecipitated in 5 L of methanol. Water and solvent were removed at room temperature under vacuum to obtain chloro-substituted styrene-isoprene-styrene secondary polymer (SIS-Cl).

[0087] (Step 2) ATRP alkylation A 250 mL flask was charged with 5 g of the second polymer (SIS-Cl) obtained in Step 1 (number of moles of isoprene-derived B' block in 5 g: 31.765 mmol), 200 mL of toluene, 196.9 mL of 1-hexene (1588.5 mmol, 50 moles per mole of B' block), 1.8 g of copper(I) bromide, 2.6 mL of pentamethyldiethylenetriamine, and a magnetic bar, and the reaction was carried out at 60 °C for 1.5 hours. After the reaction was completed, the solution was filtered through an aluminum oxide column, and the solvent was removed under vacuum at 60 °C. The resulting mixture was then precipitated in 2 L of methanol and reprecipitated in 2 L of methanol. The water and solvent were removed under vacuum at room temperature to obtain a styrene-isoprene-styrene tertiary polymer (SIS-hex-Cl) containing 1-hexene units and substituted with a chloro group at the side chain terminal.

[0088] (Step 3) Crosslinking A 20 mL vial was charged with 0.3 g of the third polymer (SIS-hex-Cl) obtained in Step 2 (number of moles of isoprene-derived B″ block in 0.3 g: 1.88 mmol), 6 mL of the organic solvent tetrahydrofuran, 0.0487 g of N,N,N′,N′-tetramethyl-1,6-hexanediamine (0.283 mmol, 0.15 moles per mole of B″ block), and a magnetic bar, and the mixture was stirred at room temperature for 5 minutes to produce a polymer solution containing a crosslinked structure represented by XL-SIS-hex-Cl.

[0089] Then, the polymer solution was uniformly applied to a Petri dish with a diameter of 9 cm to a thickness of 60 μm, and then dried in a vacuum at 60° C. for 24 hours to remove the solvent, thereby preparing a membrane.

[0090] Next, the membrane was heat-treated at 100°C under vacuum for 48 hours to carry out an additional reaction, resulting in a transparent anion exchange membrane (XL-SIS-hex-QA) with a thickness of 30 μm, the photograph of which is shown in Figure 1.

[0091] Test Example 1: 1 H NMR analysis The second polymer (SIS-Cl) and the third polymer (SIS-hex-Cl) prepared in Steps 1 and 2 of Example 1 1 The H NMR analysis spectrum is shown in Figure 2. In addition, to confirm whether the synthesis was carried out properly, the first polymer (SIS) 1 The H NMR analysis spectrum is shown in Figure 3. 1 1 H NMR spectra were obtained on an Agilent 400-MR (400 MHz) instrument using CDCl 3 as the reference or internal deuterium lock.

[0092] Comparing the spectrum of the second polymer (SIS-Cl) in Figure 2 with the spectrum of the first polymer (SIS) in Figure 3, it can be seen that the first polymer (SIS) in Figure 3 has a high intensity peak at 4.5 to 5.3 ppm due to isoprene groups, whereas the second polymer (SIS-Cl) in Figure 2 barely exhibits such peaks due to isoprene groups. This indicates that the synthesis of the second polymer from the first polymer was successful, and the conversion of the synthesis of the second polymer from the first polymer, calculated from the ratio of the isoprene group peaks, was 98% or more.

[0093] Comparing the spectra of the second polymer (SIS-Cl) and the third polymer (SIS-hex-Cl) in Figure 2, it can be seen that the peak at 2.2 ppm, which appears due to tertiary carbon, in the third polymer (SIS-hex-Cl) is stronger than the peak at 2.2 ppm in the second polymer (SIS-Cl). This is due to the carbon represented by b introduced by the 1-hexene compound. This peak comparison confirms that the synthesis of the third polymer was carried out successfully from step 2 of Example 1.

[0094] Meanwhile, the n value of the third polymer (SIS-hex-Cl) prepared in step 2 of Example 1 was 0.05, which is the same as that of the second polymer (SIS-Cl) and the third polymer (SIS-hex-Cl). 1 The integral value of the peak represented by a in the H NMR analysis spectrum and the integral value of the peak represented by a+b were determined, and it was confirmed that n was a value of 1 to 3.

[0095] Test Example 2: FT-IR analysis FT-IR analysis was performed on the first polymer (SIS), which was the starting material in Example 1, and the second polymer (SIS-Cl), third polymer (SIS-hex-Cl), and anion exchange membrane (X1-SIS-hex-QA) produced in Example 1. The results are shown in Figure 4.

[0096] Referring to FIG. 4, when comparing the spectrum of the third polymer (SIS-hex-Cl) and the spectrum of the anion exchange membrane (X1-SIS-hex-QA), the third polymer (SIS-hex-Cl) has a quaternary ammonium structure and a 985 cm band due to a carbon-nitrogen bond. -1 In contrast to the anion exchange membrane (Xl-SIS-hex-QA), the peak due to the carbon-nitrogen bond in the quaternary ammonium structure is strong. This confirms that the anion exchange membrane (Xl-SIS-hex-QA) with a quaternary ammonium structure was successfully produced from the tertiary polymer (SIS-hex-Cl).

[0097] Test Example 3: Performance measurement of anion exchange membrane The ion exchange capacity of the anion exchange membrane manufactured in the above example was 1 The relative integral areas between the aromatic and methyl protons in the H NMR spectrum were calculated and compared. The results are shown in Table 1, in comparison with a commercially available anion exchange membrane (Fumasep® FAA-3-50, manufactured by Fumatech).

[0098] In addition, the water content and swelling degree of the anion exchange membrane and FAA-3-50 prepared in the above example were measured by OH. - Specifically, after ion exchange, the membrane was washed several times with ultrapure water, and then the hydrated membrane was quickly wiped with filter paper to remove the water on the surface. Then, the weight of the hydrated membrane (m wet ) and unidirectional length (L wet ), and then the membrane was covered with filter paper to prevent shrinkage and dried in a vacuum oven at 90°C for 24 hours to maintain a constant weight. The weight of the dried membrane (m dry ) and unidirectional length (L dry Finally, the water content and swelling degree were calculated by the following formulas 1 and 2, respectively, and the results are shown in Table 1. [Formula 1] Moisture content (%)=[(m wet -m dry ) / m dry ] x 100 [Formula 2] Swelling degree (%)=[(L wet -L dry ) / L dry ] x 100

[0099] In addition, the ionic conductivities of the anion exchange membranes prepared in the above examples and FAA-3-50 were measured by measuring the thickness of each anion exchange membrane using high-purity DI water from Duksan Chemical Co., Ltd., and then connecting them to a 4-probe conductivity cell from Bekktech Co., Ltd. with AC impedance at 80°C / 100% RH. The results are shown in Table 1.

[0100] [Table 1]

[0101] Referring to Table 1 above, it can be seen that the anion exchange membrane containing the polymer having a crosslinked structure represented by Chemical Formula 1 in Example 1 exhibits improved ion exchange performance, water content, swelling degree, and ionic conductivity compared to the anion exchange membrane (FAA-3-50) in Comparative Example 1.

Claims

1. A polymer comprising a crosslinked structure represented by the following chemical formula 1: 【Chemistry 1】 In the above Chemical Formula 1, R １ and R ２ are each independently a halogen or C １－４ is alkyl, a and b are each independently an integer from 0 to 3; R ３ and R ４ are each independently hydrogen or C １－４ is alkyl, R ５ is C １－１０ is alkyl, R ６ Or R ９ are each independently C １－４ is alkyl, L is C １－１０ is alkylene, Q is a halogen; n is an integer from 1 to 3; x, y and z each represent the mole fraction of each repeating unit in the polymer, and x+y+z=1.

2. R １ and R ２ are each independently chloro, bromo, methyl, or tert-butyl; 2. The polymer of claim 1, wherein a and b are each independently 0 or 1.

3. R ３ The polymer of claim 1 , wherein is methyl.

4. R ４ is hydrogen, R ５ The polymer of claim 1, wherein is n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, or n-octyl.

5. R ６ Or R ９ The polymer of claim 1 , wherein each of

6. 2. The polymer of claim 1, wherein L is butylene, pentylene, hexylene, or heptylene.

7. 2. The polymer of claim 1, wherein Q is chloro.

8. 2. The polymer of claim 1, wherein x+z is from 0.2 to 0.

5.

9. The polymer of claim 1, wherein the polymer is derived from a triple block copolymer represented by the following Chemical Formula 1-1 having a weight average molecular weight of 50,000 to 400,000 g / mol: 【Chemistry 2】 In the above Chemical Formula 1-1, R １ , R ２ , a, b, x, y and z are as defined in claim 1.

10. Step 1: reacting a first polymer, which is an ABC triblock copolymer represented by the following chemical formula 1-1, with hydrogen halide to prepare a second polymer, which is an ABC triblock copolymer represented by the following chemical formula 1-2: Step 2: reacting the second polymer represented by the following formula 1-2 with an alkene represented by the following formula 1a to prepare a third polymer, which is an A-B″-C triple block copolymer represented by the following formula 1-3; and Step 3: reacting a third polymer represented by the following formula 1-3 with a diamine represented by the following formula 1b to prepare a polymer including a crosslinked structure represented by the following formula 1: A method for producing a polymer having a crosslinked structure represented by the following chemical formula 1, comprising: 【Chemistry 3A】 【Chemistry 3B】 In the above Chemical Formula 1, Chemical Formula 1-1 to Chemical Formula 1-3, 1a and 1b, R １ and R ２ are each independently a halogen or C １－４ is alkyl, a and b are each independently an integer from 0 to 3; R ３ and R ４ are each independently hydrogen or C １－４ is alkyl, R ５ is C １－１０ is alkyl, R ６ Or R ９ are each independently C １－４ is alkyl, L is C １－１０ is alkylene, Q is a halogen; n is an integer from 1 to 3; x, y, and z represent the mole fraction of each repeating unit in the polymer, where x+y+z=1.

11. 11. The method of claim 10, wherein in step 1, the hydrogen halide is used in an amount of 2 to 3 moles per mole of the B block unit in the first polymer represented by Formula 1-1.

12. 11. The method of claim 10, wherein in step 2, the alkene represented by Formula 1a is used in an amount of 10 to 100 moles per mole of the B′ block unit in the second polymer represented by Formula 1-2.

13. The method according to claim 10, wherein the reaction in step 2 is carried out at 50 to 100°C for 1 to 72 hours.

14. 11. The method of claim 10, wherein in step 3, the diamine represented by Formula 1b is used in an amount of 0.1 to 0.3 moles per mole of the B″ block unit in the third polymer represented by Formulas 1-3.

15. An anion exchange membrane comprising the polymer of claim 1.

16. Step 1: reacting a third polymer represented by the following formula 1-3 with a diamine represented by the following formula 1b in an organic solvent to prepare a polymer solution containing a crosslinked structure represented by the following formula 1; and The method for producing an anion exchange membrane includes a step (Step 2) of casting the polymer solution on a substrate and then drying the cast membrane. [Chemistry 4A] 【Chemistry 4B】 In the above formulas 1, 1-3 and 1b, R １ and R ２ are each independently a halogen or C １－４ is alkyl, a and b are each independently an integer from 0 to 3; R ３ and R ４ are each independently hydrogen or C １－４ is alkyl, R ５ is C １－１０ is alkyl, R ６ Or R ９ are each independently C １－４ is alkyl, L is C １－１０ is alkylene, Q is a halogen; n is an integer from 1 to 3; x, y, and z represent the mole fraction of each repeating unit in the polymer, where x+y+z=1.

17. 17. The method according to claim 16, wherein in step 1, the organic solvent is at least one selected from the group consisting of tetrahydrofuran, chloroform, toluene, and dichloromethane.

18. The method according to claim 16, wherein the drying in step 2 is carried out at 40 to 80°C for 12 to 24 hours.

19. 17. The method of claim 16, further comprising the step of heat treating the substrate at 80 to 150[deg.] C. for 24 to 72 hours after step 2.

20. The method according to claim 16, wherein the anion exchange membrane is manufactured to a thickness of 20 to 80 μm.

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