Cationic compounds for anion exchange membranes

Abstract

Amidinium-functionalized compound, wherein the compound has a structure according to general formula I or general formula II. [Formula 1] JPEG2026512571000033.jpg55164 [C2] In formula JPEG2026512571000034.jpg54164, ·R5 and R9 are any substituents other than hydrogen; ·R1 to R4 are independently selected from the group consisting of alkyl groups, alkenyl groups, alkynyl groups, aralkyl groups, alkaryl groups, and heteroaryl groups, or any of R1 and R3, R1 and R4, R1 and R2, R3 and R4, R2 and R3, or R2 and R4 are five-membered ~Represents the atoms necessary to form an eight-membered non-aromatic ring; ·R6~R8 are independently selected from the group consisting of hydrogen, alkyl groups, alkenyl groups, alkynyl groups, aralkyl groups, alkaryl groups, aryl or heteroaryl groups, halogen groups, ether groups, nitro groups, and amine groups, or any of R5 and R6, R6 and R7, R7 and R8, or R8 and R9 represents the atoms necessary to form a five-membered to eight-membered ring; ·X - The formula is characterized in that it is an anion, and at least one of the R1 to R9 groups has a polymerizable group or an atom necessary for linking the amidinium group to the polymer.

Description

[Technical Field]

[0001] This invention relates to the field of anion exchange membranes, more specifically to cationic monomers and cationic polymers for their manufacture. The invention has potential applications in water electrolysis. [Background technology]

[0002] To guide future generations towards a climate-neutral world, alternatives to fossil fuels are becoming increasingly important. Renewable energy is generated from natural sources that can be replenished over time, such as sunlight, wind, hydro, geothermal, bioenergy, and tidal / wave power. Water electrolysis is one technology for a sustainable future that utilizes these renewable energy sources to produce green hydrogen. Hydrogen gas is an efficient energy carrier and storage medium and can be a substitute for fossil fuels for power generation.

[0003] Although alkaline water electrolysis (AWE) is an established technology for hydrogen production, combining it with renewable energy presents challenges due to the inherent intermittent availability associated with this type of energy. Intermittent power supply leads to fluctuations in voltage and current, resulting in increased gas crossover during the electrolysis process. This is a problem related to the porous structure of AWE separators.

[0004] Proton exchange membrane (PEM) water electrolysis is a promising alternative to AWE, but its industrialization is limited due to the need to use expensive platinum and iridium catalysts. On the other hand, anion exchange membrane (AEM) water electrolysis combines the advantages of PEM water electrolysis with the use of inexpensive and abundant catalyst materials.

[0005] In the context of water electrolysis, the use of AEMs offers a wide range of advantages over PEMs and AWEs, such as relatively lower costs, pressure resistance, large operating capacity, and rapid response to changes in operating conditions. AEMs must be thin, stable, airtight, and highly conductive polymer films. Typically, AEMs are cationic polymer electrolytes that transport charge across the film via hydroxide ions. Cationic groups can exist as pendant functional groups or as part of the polymer backbone. Examples of cationic groups include quaternary ammonium groups, guanidinium groups, imidazolium groups, benzimidazolium groups, phosphonium groups, and cobalt-cenium groups. Due to their ion exchange capabilities, AEMs are applied not only to water electrolysis but also to (waste) water treatment, electrodialysis, chlor-alkali production, desalination, batteries, and fuel cells.

[0006] Patent Document 1 (EVONIK) discloses a benzimidazolium unit-containing polymer compound for anion exchange membranes, and Patent Document 2 (EVONIK) describes a spiro or piperidine structural unit-containing polymer compound as an anion-conducting membrane. The membrane has high mechanical stability, low swelling properties, and extremely high anion conductivity.

[0007] One specific problem with AEM is its low alkali stability, which stems from decomposition reactions occurring at the polymer backbone or functional groups. Decomposition at the backbone leads to mechanical defects in the film, while decomposition at the functional groups reduces ionic conductivity. Decomposition often occurs through nucleophilic attack by hydroxide ions, which can destroy anion exchange capacity and hydroxide ion conductivity.

[0008] Patent Document 3 (FUJIFILM) discloses a cationic charged polymer film, which has cationic charged nitrogen atoms in its aromatic heterocycle, and as a result has high ion exchange capacity. Furthermore, it possesses low electrical resistance even after being exposed to harsh conditions.

[0009] Patent Document 4 (IONOMR) and Patent Document 5 (IONOMR) are based on methylated polybenzimidazole and describe a cationic membrane that can be used in an anion exchange resin, having a sterically hindered and more alkali-stable cationic group by introducing methyl groups at both ortho-positions of the linked 2-phenyl group.

[0010] However, in order to prevent chemical and physical decomposition, it is still necessary to further improve the alkali stability of AEM, thereby increasing the durability of AEM.

Prior Art Documents

Patent Documents

[0011]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Summary of the Invention

[0012] An object of the present invention is to provide a cationic monomer or cationic polymer having improved stability under alkaline conditions.

[0013] This object is achieved by an amidinium-functionalized compound as defined in claim 1.

[0014] A further object of the present invention is to provide a method for preparing such a cationic polymer.

[0015] A further object of the present invention will become apparent from the following description.

Modes for Carrying Out the Invention

[0016] Definition The term "monofunctional", for example in the case of a monofunctional polymerizable compound, means that the polymerizable compound has one polymerizable group.

[0017] The term "bifunctional", for example in the case of a bifunctional polymerizable compound, means that the polymerizable compound has two polymerizable groups.

[0018] The term "polyfunctional" or "multifunctional", for example in the case of a polyfunctional polymerizable compound, means that the polymerizable compound has more than two polymerizable groups.

[0019] The term "alkyl" means all possible deformation forms for alkyl groups of each number of carbon atoms, that is, methyl, ethyl, for those with 3 carbon atoms, n-propyl and isopropyl, for those with 4 carbon atoms, n-butyl, isobutyl, and tert-butyl, for those with 5 carbon atoms, n-pentyl, 1,1-dimethylpropyl, 2,2-dimethylpropyl, and 2-methylbutyl, etc.

[0020] Unless otherwise specified, a substituted or unsubstituted alkyl group is preferably a C1-C6-alkyl group.

[0021] Unless otherwise specified, a substituted or unsubstituted alkenyl group is preferably a C2-C6-alkenyl group.

[0022] Unless otherwise specified, a substituted or unsubstituted alkynyl group is preferably a C2-C6-alkynyl group.

[0023] Unless otherwise specified, a substituted or unsubstituted aralkyl group is preferably a phenyl or naphthyl group having one, two, three, or more C1-C6-alkyl groups.

[0024] Unless otherwise specified, substituted or unsubstituted aralkyl groups are preferably C7-C groups having a phenyl or naphthyl group. 20 -It is an alkyl group.

[0025] Unless otherwise specified, the substituted or unsubstituted aryl group is preferably a phenyl group or a naphthyl group.

[0026] Unless otherwise specified, substituted or unsubstituted heteroaryl groups are preferably five- or six-membered rings substituted with one, two, or three oxygen, nitrogen, sulfur, selenium atoms, or a combination thereof.

[0027] The term "substituted" means, for example, that the alkyl group can be substituted with an atom other than the atoms normally present in such a group (i.e., carbon and hydrogen). For example, a substituted alkyl group may contain a halogen atom or a thiol group. An unsubstituted alkyl group contains only carbon and hydrogen atoms.

[0028] Unless otherwise specified, substituted alkyl groups, substituted alkenyl groups, substituted alkynyl groups, substituted aralkyl groups, substituted alkaryl groups, substituted aryl groups, and substituted heteroaryl groups are preferably substituted with one or more components selected from the group consisting of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and tert-butyl, esters, amides, amines, ethers, thioethers, ketones, aldehydes, sulfoxides, sulfones, sulfonic acid esters, sulfonamides, -Cl, -Br, -I, -OH, -SH, -CN, and -NO2.

[0029] Amidinium-functionalized compounds The amidinium-functionalized compound according to the present invention has a structure according to general formula I or general formula II. [ka] [ka] During the ceremony R5 and R9 are any substituents other than hydrogen; R1 to R4 are independently selected from the group consisting of substituted or unsubstituted alkyl groups, substituted or unsubstituted alkenyl groups, substituted or unsubstituted alkynyl groups, substituted or unsubstituted aralkyl groups, substituted or unsubstituted alkaryl groups, and substituted or unsubstituted aryl or heteroaryl groups, or any of R1 and R3, R1 and R4, R1 and R2, R3 and R4, R2 and R3, or R2 and R4 represent atoms necessary to form a five-membered to eight-membered non-aromatic ring; R6-R8 are independently selected from the group consisting of hydrogen, substituted or unsubstituted alkyl groups, substituted or unsubstituted alkenyl groups, substituted or unsubstituted alkynyl groups, substituted or unsubstituted aralkyl groups, substituted or unsubstituted alkaryl groups, substituted or unsubstituted aryl or heteroaryl groups, halogens, ethers, nitros, and amines, or any of the substituents R5 and R6, R6 and R7, R7 and R8, or R8 and R9 represent atoms necessary to form a five-membered to eight-membered ring; ·X - It is an anion that cancels out the charge of the cation; Furthermore, during the ceremony, At least one of R1 to R9 has a polymerizable group or an atom necessary for linking the amidinium group to the polymer.

[0030] AEMs are typically positively charged polymers having cationic groups that enable the transport of anions, such as hydroxide ions, across the membrane. Examples of cationic groups include ammonium, imidazolium, guanidinium, and phosphonium groups. One of the major challenges in designing AEMs is overcoming their low alkali stability, which is partly due to dealkylation reactions occurring at these cationic groups.

[0031] The compounds according to the present invention have an amidinium group as a cationic group. The amidinium group is a cationic group obtained by quaternization of the amidine group RC(NR')NR''R''', where R, R', R'', and R''' can be the same or different. Amidine is an imine derivative of amide. The amidinium group has a higher pKa of the corresponding base compared to the corresponding base of the typically used cationic groups listed above. This is thought to reduce dealkylation reactions and therefore lead to higher alkali stability.

[0032] To further enhance the alkali stability of the compound, the amidinium-functionalized compound according to the present invention has a group that sterically protects the amidinium group from nucleophilic attack by a cation. To optimally protect the amidinium group, the protecting group is introduced at both ortho positions of the 2-phenyl group, i.e., R5 and R9. Therefore, R5 and R9 are any substituents other than hydrogen. R5 and R9 are preferably alkali-stable substituents, and alkali stability A functional group is defined as one that exhibits less than 5% degradation when treated in 2M KOH at 80°C for 7 days. More preferably, the degradation is less than 2%, and most preferably, no detectable degradation is present.

[0033] R5 and R9 can be independently selected from the group consisting of substituted or unsubstituted alkyl groups, substituted or unsubstituted alkenyl groups, substituted or unsubstituted alkynyl groups, substituted or unsubstituted aralkyl groups, substituted or unsubstituted alkaryl groups, substituted or unsubstituted aryl or heteroaryl groups, halogens, ether groups, nitro groups, and amine groups.

[0034] Preferably, R5 and R9 are independently selected from the group consisting of substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, halogens, and ether groups. More preferably, R5 and R9 are independently selected from substituted or unsubstituted alkyl groups and substituted or unsubstituted aryl groups, and most preferably, R5 and R9 are independently selected from unsubstituted C1-C4 alkyl groups and substituted or unsubstituted phenyl groups, with phenyl and methyl groups being particularly preferred. When R5 and R9 are independently methyl or phenyl groups, the amidinium group is sufficiently sterically protected against nucleophilic attack, while the synthesis of the desired amidinium-functionalized compound is not substantially hindered sterically, as will be described below.

[0035] The amidinium-functionalized compound according to the present invention can be either a monomer or a polymer. If at least one of R1 to R9 has a polymerizable group, the amidinium-functionalized compound is referred to as an amidinium-functionalized monomer, which will be described in more detail below. If at least one of R1 to R9 has an atom necessary for linking the amidinium group to the polymer, the amidinium-functionalized compound is referred to as an amidinium-functionalized polymer, which will be described in more detail below. In a preferred embodiment, at least one of R1, R2, R3, R4, and R7 has a polymerizable group, as further disclosed. In another preferred embodiment, at least one of R1, R2, R3, R4, and R7 has an atom necessary to link the amidinium group to the polymer backbone. In a further preferred embodiment, at least two of R1, R2, R3, R4, and R7 are incorporated into the polymer backbone. When at least two of R1, R2, R3, R4, and R7 are incorporated into the polymer backbone, the amidinium group also becomes part of the polymer backbone. The structure of the amidinium-functionalized polymer according to the present invention will be examined in more detail.

[0036] Preferably, R6 to R8 are independently selected from the group consisting of hydrogen, substituted or unsubstituted alkyl groups, and substituted or unsubstituted aryl groups. More preferably, R6 to R8 are selected from hydrogen and C1-C6 alkyl groups, most preferably from hydrogen and methyl groups.

[0037] The amidinium-functionalized compound of the present invention contains an anion X that cancels out the cationic charge of the compound. - It has. It is not limited to X - The following are selected from the group consisting of iodide ions, bromide ions, chloride ions, fluoride ions, triiodide ions, hydroxide ions, carbonate ions, bicarbonate ions, cyanide ions, acetate ions, nitrate ions, sulfate ions, alkyl sulfate ions, perfluoroalkyl sulfonate ions, aryl sulfonate ions, perchlorate ions, tetrachloroaluminate ions, tetrafluoroborate ions, alkyl borate ions, phosphate ions, halophosphate ions, alkyl phosphate ions, trifluoromethanesulfonate ions, tosylate ions, mesylate ions, alkyl carboxylate ions, tetrakis(3,5-bis(trifluoromethyl)phenyl)borate ions, bis(trifluoromethane)sulfonamide, and any combination thereof.

[0038] Suitable anions are selected from the group consisting of bromide ions, chloride ions, hydroxide ions, benzenesulfonate ions, tosylate ions, and mesylate ions.

[0039] The amidinium-functionalized compounds according to the present invention are preferably prepared according to the synthetic strategy described below: [ka] In the formula, R1 to R9 are as defined above, and M represents a metal atom, which is optionally bonded to a halide atom.

[0040] In the first step, the substituted urea R1HNCONHR4 or thiourea R1HNCSNHR4 is converted to the corresponding carbodiimide using any method known in the literature, followed by the addition of a sterically hindered aromatic organometallic reagent having R5 and R9 as hindering groups. Preferably, aryllithium and Grignard reagents are used as organometallic reagents. Suitable sterically hindered aromatic organometallic reagents are: (2,4,6-trimethylphenyl)magnesium bromide, (2,4,6-trimethylphenyl)magnesium chloride, (2,4,6-trimethylphenyl)lithium, (2,6-dimethylphenyl)magnesium bromide, (2,6-dimethylphenyl)lithium, (2,3,4,5,6-pentamethylphenyl)magnesium bromide, (2,3,4,5,6-pentamethylphenyl)lithium, (4-methoxy-2,6-dimethylphenyl)magnesium Bromide, (4-methoxy-2,6-dimethylphenyl)lithium, (2,6-dimethoxyphenyl)magnesium bromide, (2,6-dimethoxyphenyl)lithium, (2,4,6-trimethoxyphenyl)magnesium bromide, (2,4,6-trimethoxyphenyl)lithium, (2,6-diphenylphenyl)magnesium bromide, (2,6-diphenyl(diphenly)phenyl)lithium, (2,4,6-triphenylphenyl)magnesium bromide, and (2,4,6-triphenylphenyl)lithium.

[0041] Next, the resulting amidine is alkylated with the first alkylating reagent R3-X, followed by quaternary fermentation with the second alkylating agent R2-X. R2 and R3 are as defined above and can be the same or different. Alkylating reagents are also called alkylating agents. Suitable alkylating agents are alkyl halides, such as alkyl bromides, alkyl iodides, alkyl chlorides, alkyl fluorides, etc. Other typical alkylating agents include These include silates, mesilates, and benzenesulfonates.

[0042] Amidinium-functionalized compounds having polymerizable groups According to one embodiment of the present invention, the amidinium-functionalized compound is an amidinium-functionalized monomer. In this case, at least one of R1 to R9 is a polymerizable group. Preferably, at least one of R1, R2, R3, R4, or R7 is a polymerizable group, which is selected from the group consisting of styrene, epoxy, oxetane, vinyl ether, and alkene. Preferred polymerizable groups are styrene, vinyl ether, and alkene groups. Most preferably, the polymerizable group is a styrene group.

[0043] Amidinium-functionalized monomers may have one or more polymerizable groups. Preferably, amidinium-functionalized monomers are monofunctional, i.e., amidinium-functionalized monomers have one polymerizable group.

[0044] Amidinium-functionalized monomers are preferably prepared using amidine-functionalized monomers as precursor compounds. These amidine-functionalized monomers can be converted to amidinium-functionalized monomers by quaternization using a suitable alkylating agent. Particularly preferred strategic routes for obtaining amidinium-functionalized monomers are as described above.

[0045] Examples of monomers according to the present invention, though not limited to those described above, are listed in Table 1. Table 1 [Table 1] TIFF2026512571000006.tif209170TIFF2026512571000007.tif226170TIFF2026512571000008.tif186170TIFF2026512571000009.tif129168

[0046] Amidinium-functionalized polymer According to another embodiment of the present invention, the amidinium-functionalized compound is an amidinium-functionalized polymer. In this case, at least one of R1 to R9 has an atom necessary for linking the amidinium group to the polymer. Preferably, at least one of R1, R2, R3, R4, and R7 has an atom necessary for linking the amidinium group to the polymer backbone.

[0047] In another preferred embodiment, at least two of R1, R2, R3, R4, and R7 are incorporated into the polymer backbone. When at least two of R1, R2, R3, R4, and R7 are incorporated into the polymer backbone, the amidinium groups become part of the polymer backbone.

[0048] More preferably, the polymer according to the present invention contains monomer units of the above-mentioned amidinium-functionalized monomer. This means that the polymer according to the present invention contains monomer units derived from the above-mentioned amidinium-functionalized monomer. A monomer unit is defined as the largest structural unit in a single monomer molecule that contributes to the structure of a macromolecule (IUPAC). If the polymer is a homopolymer, the monomer unit can also be called a repeating unit.

[0049] The amidinium-functionalized polymer according to the present invention can be any type of polymer. The polymer can be a linear polymer, a star-shaped polymer, a cross-linked polymer, or a (super)branched polymer.

[0050] The amidinium group is a part incorporated into the polymer backbone, also known as the polymer main chain. If possible, it can also be part of a side chain covalently bonded to the polymer backbone. The definition of a polymer backbone or backbone is known to those skilled in the art and can be defined as follows: "A straight chain to which all other chains, whether long, short, or both, can be considered pendants" (IUPAC definition). For example, polyolefins, such as polyethylene, polypropylene, polystyrene, and acrylates, have a backbone composed of carbon...CCCC.... A polymer side chain is a chemical group added to the backbone. Side chains can be short, oligomeric, or polymeric.

[0051] The amidinium group can be an integrated part of the polymer backbone. This means that at least one nitrogen atom of the amidinium group is incorporated into the polymer backbone. Integrating the amidinium group into the polymer backbone may offer the advantage of further improving the mechanical properties of the AEM by further reducing decomposition reactions. Another benefit is the possibility of better ionic conductivity. Preferably, both nitrogen atoms of the amidinium group are incorporated into the polymer backbone.

[0052] The amidinium group can also be part of the side chains of the polymer skeleton. This has the advantage of allowing the polymer skeleton to be designed in a way that further enhances alkali stability or modulates the mechanical properties of the AEM.

[0053] The amidinium-functionalized polymer can be selected from amidinium-functionalized polyolefins, polyethylenes, polyacrylates, polymethacrylates, polystyrenes, polysulfones, poly(phenylene oxide), poly(phenylene), poly(benzimidazolium), poly(arylene ether ketone), polyarylene or poly(arylene ether sulfone), polyether ether ketone, polyimide, or polyamide. Preferably, the amidinium-functionalized polymer is amidinium-functionalized polystyrene.

[0054] Any polymerization method can be used to prepare the polymers according to the present invention, including free radical polymerization, living free radical polymerization, ring-opening polymerization, cationic polymerization, anionic polymerization, metathesis polymerization, Ziegler-Natta polymerization, polyaddition, and polycondensation. Preferred polymerization techniques are free radical polymerization and living free radical polymerization.

[0055] Polymerization reactions can be initiated using any suitable initiator of any type. In radical polymerization processes, any radical polymerization initiator, such as a redox initiator, photoinitiator, or thermal initiator, can be used. A preferred initiator is a thermal polymerization initiator, which generates radicals when exposed to heat. Examples of thermal polymerization initiators include organic peroxides, inorganic peroxides, and azo initiators, of which azobisisobutyronitrile (AIBN) is the most common example. Other azo initiators, such as 2,2'-azobis(2-(2-imidazolin-2-yl)propane) dihydrochloride; 2,2'-azobis(N,N'-methylene isobutylamidine) dihydrochloride; 2,2'-azobis-(amidinopropane) dihydrochloride; 2,2'-azobis(2-methylpropionamidine) dihydrochloride; 2,2'-azobis(2,4-dimethylvaleronitrile); 2,2'-azobis(2-methylbutyronitrile); or dimethyl-2,2'-azobis(2-methylpropionate), are commercially available from WAKO Chemicals or Vesta Chemicals.

[0056] A suitable amount of radical initiator is 0.02 to 20 mol%, more preferably 0.1 to 10 mol%, and most preferably 0.5 to 5 mol%, relative to the total amount of monomer.

[0057] The polymer according to the present invention can also be obtained by a post-derivative method of an existing polymer backbone. A preferred post-derivation method involves quaternizing the amidine-functionalized precursor polymer using an alkylating agent, such as alkyl tosylate. The amidine-functionalized polymer can preferably be prepared by polymerizing the amidine-functionalized monomer using free radical polymerization or living free radical polymerization techniques as described above. The amidine-functionalized precursor monomer can be prepared as described above.

[0058] The polymer according to the present invention may be a homopolymer or a copolymer containing two or more monomers. The copolymer may be, but is not limited to, a random copolymer, a block copolymer, an alternating copolymer, a graft copolymer, a gradient copolymer, or a comb or comb-like copolymer.

[0059] Copolymers are typically prepared from a mixture of monomers in predetermined ratios. Different ratios of monomers can be used depending on the desired properties. It is also possible to obtain block copolymers or gradient copolymers by adding monomers at different points in the polymerization process. Block or block-like copolymers exhibit different characteristics compared to random copolymers. Amidinium-functionalized monomers can be combined with any other type of monomer. Mixtures of different amidinium-functionalized monomers are available. Amidinium-functionalized monomers can be copolymerized with a second type of amidinium-functionalized monomer or with another cationic-functionalized monomer, such as guanidinium-functionalized monomer, benzimidazolium-functionalized monomer, or ammonium-functionalized monomer. Copolymers can also be prepared by copolymerizing amidinium-functionalized monomers with nonionic monomers, such as styrene. A suitable amount of cationic functionalized monomer in the copolymer is 10 to 90 mol%, more preferably 20 to 80 mol%, and most preferably 30 to 70 mol%, relative to the total moles of monomer.

[0060] In another embodiment of the present invention, the amidinium-functionalized polymer according to the present invention is provided in the form of a polymer dispersion. This polymer dispersion can be mixed with a catalyst, which can be deposited on a substrate such as a porous metal structure or a membrane. Following the removal of the liquid medium, the polymer acts as a binder to bond the catalyst to the substrate (see below).

[0061] The polymer dispersion can be provided in both aqueous and solvent media. Preferably, the polymer dispersion is provided in an aqueous or alcoholic form such as ethanol. Preferably, the dispersion contains 2.5 to 70% by weight, more preferably 10 to 50% by weight, and most preferably 5 to 25% by weight of the amidinium-functionalized polymer.

[0062] The amidinium-functionalized polymer according to the present invention is self-dispersible by electrostatic force or dispersible by a dispersant, which can be a polymer dispersant or a non-polymer surfactant. The dispersant can be nonionic, cationic, or anionic. Since the amidinium-functionalized polymer is inherently cationic, cationic or nonionic dispersants are preferred. Suitable dispersants include DISPERBYK® dispersant (supplied by BYK CHEMIE), JONCRYL® dispersant (supplied by JOHNSON POLYMERS), and SOLSPERSE® dispersant (supplied by Lubrisol). Another example is poly(diallyldimethylammonium chloride), also known as PolyDADMAC. A detailed list of non-polymer dispersants and some polymer dispersants can be found in MCCUTCHEON. Functional Materials, North American Edition. Glen Rock, NJ: Manufacturing Confectioner. Disclosed in Publishing Co., 1990, pp. 110-129.

[0063] Polymer dispersions can be obtained using any type of technique, such as solvent evaporation, milling, emulsion polymerization, mini-emulsion polymerization, or dispersion polymerization. Preferred dispersion techniques are solvent evaporation and mini-emulsion polymerization.

[0064] Typical polymers and copolymers according to the present invention are shown in Table 2 below, but are not limited to these. The structures are general structures, and the ratio of comonomers can be changed according to the desired properties. Copolymers can be random, block, or gradient copolymers. [Table 2] TIFF2026512571000011.tif143170

[0065] Anion exchange membrane The amidinium-functionalized polymer according to the present invention can be used in any application where a cationic polymer is required, such as, for example, as a coagulant in (waste) water treatment or as an additive in fabric finishing. Preferably, the amidinium-functionalized polymer is used in the manufacture of anion exchange membranes (AEMs).

[0066] AEM is an anion (e.g., OH) in electrochemical reactions. - Cl - , Br - This enables the transport of hydroxide ions (OH) from the cathode to the anode. The AEM can be used in any electrochemical process, such processes being selected from electrolysis, electrodialysis, and fuel cell technology. Preferably, the anion exchange membrane of the present invention is used in electrolysis, more preferably in water electrolysis. In water electrolysis, hydroxide ions (OH) - ) are transported through the AEM together with water molecules. The AEM according to the present invention can also be used in batteries, sensors, and actuators.

[0067] There is an important balance to be found between the mechanical properties and conductivity of the AEM. Preferably, the AEM has a long lifespan, which can be achieved by a film with good mechanical properties. Typically, thicker films result in improved mechanical properties of the AEM and reduced hydrogen and oxygen crossover. The AEM film according to the present invention preferably has a dry thickness of 10 to 100 μm, more preferably 20 to 80 μm, and most preferably 30 to 60 μm. If the EM is wet, the membrane may swell, potentially increasing in thickness.

[0068] However, if the thickness is too great, the ion resistance increases, which reduces the ion conductivity of the AEM. High anionic conductivity is required to support large currents while minimizing resistance loss. The anionic conductivity of the AEM according to the present invention is preferably greater than 40 mS / cm, more preferably greater than 70 mS / cm, and most preferably greater than 100 mS / cm.

[0069] The thickness of the AEM not only determines the mechanical properties, but the chemical structure of the polymer used, the degree of crosslinking, and any optional additives also have an influence.

[0070] When the AEM contains chemically or physically crosslinked polymers, the AEM preferably has a swelling ratio of 5-60%, more preferably 10-50%, and most preferably 20-40%. A lower swelling ratio often results in better mechanical properties for the AEM.

[0071] The strength of the AEM is expressed by its tensile strength. The tensile strength of the AEM according to the present invention is preferably 10 to 50 MPa. More preferably, the tensile strength is 12 to 40 MPa, and most preferably 15 to 34 MPa.

[0072] Anion exchange membranes can be manufactured by any method known in the art, depending on the desired size and scale. Generally, any coating or casting technique is available. Preferred techniques include slot-die coating, extrusion coating, and dip coating. A suitable method for producing AEMs on a small scale is solution casting of a polymer solution and solvent evaporation. Solvent evaporation can be accelerated by heating, vacuum application, or a combination thereof. Another suitable method for producing AEMs consists of coating a polymer solution using a bar coater and coating knife. This process can be carried out in air or under a nitrogen atmosphere. A suitable method for large-scale AEM manufacturing is slot die coating.

[0073] The polymer solution used in the preparation of AEM can be a solution of amidinium-functionalized polymer, which can be obtained directly after polymer synthesis. However, if higher purity is desired, the amidinium-functionalized polymer can be isolated and purified after synthesis, and then redissolved in an optimal solvent, such as propylene glycol, NMP, NBP, DMSO, DMF, THF, MEK, and dioxolane. In principle, any solvent in which the polymer dissolves can be used. The polymer can also be dissolved in a solvent mixture or a water-solvent mixture. Preferred mixtures are water-isopropanol and water-ethanol. Preferably, the solvent or solvent mixture has a boiling point of less than 175°C.

[0074] AEM can also be prepared using a solution of amidine-functionalized precursor polymers and subsequently quaternized. In the first step, a nonionic film is formed, and this film is then reacted with a suitable alkylating agent to obtain a cationic polymer film.

[0075] It is further possible to increase the mechanical strength of the film by crosslinking the polymer. Any type of crosslinking reaction is available, but preferred methods include thermocuring, photocuring, electron beam irradiation, gamma irradiation, and combinations thereof. It is also possible to cure the polymer in two separate steps, meaning that the UV crosslinking step and the thermocuring step are performed sequentially, and is not limited to a specific order of steps.

[0076] The anion exchange membrane according to the present invention may have a porous or non-porous support, which may also be called a reinforcing support. While not limited to these, the support can be selected from stretched polymer films such as stretched PTFE, and polymer wire meshes, and the polymer wire mesh may be woven or nonwoven. An AEM having a support has the advantage of further improved mechanical properties.

[0077] The process for preparing an anion exchange membrane having a support preferably involves immersing the support in a polymer-containing solution or coating the support with a polymer-containing solution. Optionally, a curing reaction can be performed to crosslink the polymer and create an AEM with even greater durability.

[0078] Electrochemical apparatus including anion exchange membrane The AEM according to the present invention can be used in any electrochemical apparatus, such as an electrolytic cell, redox flow battery, fuel cell, or electrodialysis system.

[0079] The AEM according to the present invention is preferably used in a water electrolytic cell.

[0080] An electrolysis cell typically comprises two electrodes, an anode and a cathode, separated by a membrane. The electrolyte is located between the two electrodes.

[0081] When an electric current is applied to the electrolysis cell, the hydroxyl ions in the electrolyte are oxidized to oxygen at the anode, and water is reduced to hydrogen at the cathode. The hydroxyl ions formed at the cathode move to the anode through the membrane. The membrane restricts the transport of hydrogen and oxygen formed during water electrolysis from the cathode to the anode and from the anode to the cathode, respectively.

[0082] The AEM water electrolytic cell can operate with pure water. It can also operate with an electrolyte, which is typically an alkaline solution. A suitable electrolyte is an aqueous solution of an electrolyte selected from sodium hydroxide or potassium hydroxide. Potassium hydroxide electrolyte is often preferred due to its higher specific conductivity. The concentration of the electrolyte in the solution is preferably 0.01 mol / L to 2 mol / L. As a result, the pH of the electrolyte is 7 to 14, more preferably 7 to 12.

[0083] The electrolyte temperature is preferably 35°C to 100°C, more preferably 40°C to 80°C, and most preferably 45°C to 60°C.

[0084] The electrode typically comprises a substrate coated with a so-called catalyst layer. The catalyst layer can be the same or different at the anode, where oxygen is formed, and the cathode, where hydrogen is formed.

[0085] Typical electrode substrates are made of conductive materials selected from the group consisting of nickel, iron, mild steel, stainless steel, vanadium, molybdenum, copper, silver, manganese, platinum group elements, graphite, and chromium. The substrate may also be made of a conductive alloy of two or more metals or a mixture of two or more conductive materials. Preferred materials are nickel or nickel-based alloys. Nickel has good stability in strong alkaline solutions, good conductivity, and is relatively inexpensive.

[0086] The catalyst layer is preferably selected from nickel, cobalt, iron, or platinum elements. The catalyst layer may contain these elements as the metal itself, a compound (e.g., an oxide), a composite oxide, an alloy made of multiple metallic elements, or a mixture thereof. Suitable catalyst layers include nickel plating, nickel-cobalt alloy or nickel-iron alloy plating, composite oxides containing nickel and cobalt, such as LaNiO3, LaCoO3, and NiCo2O4, compounds of platinum elements, such as iridium oxide, or carbon materials, such as graphene.

[0087] Particularly preferred catalyst layers include Raney nickel. The Raney nickel structure is formed by the selective leaching of aluminum or zinc from a Ni-Al or Ni-Zn alloy. The vacancies formed during leaching result in large surface areas and high densities of lattice defects, which serve as active sites for electrocatalytic reactions.

[0088] Suitable porous electrodes and methods for preparing them are disclosed, for example, in EP-A 3575442, paragraphs 23-84.

[0089] The pore size of a porous electrode can affect the electrolysis efficiency. For example, EP-A 3575442 discloses that a suitable pore size for a porous electrode is 10 nm to a maximum of 200 nm.

[0090] The catalyst layer may also contain an organic substrate, such as a polymer, to improve durability and adhesion to the substrate. The polymer in the catalyst layer is preferably similar to the polymer in the AEM film. Most preferably, the polymer in the catalyst layer is an amidinium-functionalized polymer. The amidinium-functionalized polymer in the catalyst layer is preferably provided in the form of a polymer dispersion as described above.

[0091] The catalyst layer can also be applied to the surface of the film, resulting in a so-called catalyst coating (CCM). Such a CCM can improve the contact surface between the film surface and the catalyst layer, resulting in higher electrolysis efficiency.

[0092] The catalyst layer can be applied to the film surface by any deposition technique, such as coating, spraying, inkjet printing, gravure printing, screen printing, 3D printing, or vapor deposition.

[0093] A typical AEM water electrolysis cell consists of multiple electrolytic cells, which are also referred to as an electrolytic cell stack.

[0094] Regarding cell configuration, two types of electrolytic cells are typically used.

[0095] A unipolar (i.e., "tank-type") electrolytic cell consists of alternating anodes and anodes, separated by a membrane. All anodes are coupled in parallel as a single unit, and so are the anodes. The entire assembly is submerged in a single electrolyte bath ("tank") to form a unit cell. These units are then electrically connected in series to construct a plant-scale electrolytic cell. The total voltage applied to the entire electrolytic cell is the same as that applied to the individual unit cells.

[0096] On the other hand, in a bipolar electrolytic cell, a metal sheet (i.e., a "bipolar") electrically connects adjacent cells in series. The electrode catalyst for the negative electrode is coated on one side of the bipolar, and the catalyst for the positive electrode of the adjacent cell is coated on the opposite side. In this case, the total cell voltage is the sum of the voltages of the individual unit cells. Therefore, a stack of such cells connected in series forms a module that operates at a higher voltage and lower current than a tank-type (unipolar) design. To meet the requirements of large-scale electrolysis plants, these modules are connected in parallel to increase the current.

[0097] Membrane electrode assemblies (MEAs) can also be used in electrolytic cells. Such MEAs are typically prepared by applying a membrane, preferably without reinforcing support, to at least one porous electrode. Such MEAs are disclosed, for example, in EP-A 2831312 (Agfa Gevaert), EP3277862 (De Nora), and WO2020 / 158719 (Nippon Shokubai). Such MEAs can also be used in the electrolysis method according to the present invention. [Examples]

[0098] material All materials used in the following examples were readily available from standard suppliers, such as ALDRICH CHEMICAL Co. (Belgium) and ACROS (Belgium), unless otherwise specified. Deionized water was used.

[0099] Proglyde DMM is dipropylene glycol dimethyl ether.

[0100] TEMPO is a 2,2,6,6-tetramethylpiperidine-1-oxyl radical.

[0101] WAKO V59 is 2,2'-dimethyl-2,2'-azodibutyronitrile, supplied by Wako Chemicals GmbH.

[0102] Evaluation method molecular weight The molecular weight was determined using TLC-MS according to the following procedure. TLC was performed under the conditions given in the synthesis example. An Amazon® SL mass spectrometer (supplied by Bruker Daltonics) was connected to a CAMAG® TLC-MS interface via an Agilent® 1100 HPLC pump, and the TLC was analyzed using these. The first blank spectrum was measured by eluting a spot on the TLC plate where no compound was present with a 0.01 molar methanol solution of ammonium acetate. The second spectrum of the compound to be analyzed was measured by eluting a spot of the compound under consideration with a 0.01 molar methanol solution of ammonium acetate. The spectrum of the compound to be analyzed was obtained by subtracting the first spectrum from the second spectrum.

[0103] Example 1 The initial alkali stability of the monomers and polymers according to the present invention was evaluated using low molecular weight model compounds.

[0104] Synthesis of model compound M1 Model compound M1, having the structure shown below, is synthesized in three steps. [ka]

[0105] Step 1: Synthesis of dibutylcarbodiimide [ka] 72.55 g (0.165 mol) of dibromotriphenylphosphorane was dissolved in 190 mL of methylene chloride. The reaction mixture was cooled to 0°C, and while maintaining the temperature below 3°C, 34.1 g (0.333 mol) of triethylamine was added dropwise. While maintaining the temperature at 0°C, a solution of 22.74 g (0.132 mol) of dibutylurea dissolved in 50 mL of methylene chloride was added. The reaction was continued at 0°C for 90 minutes. While maintaining the reaction temperature below 5°C, 330 mL of water was added to the mixture over 15 minutes. The mixture was stirred for a further 15 minutes. The mixture was heated to room temperature, and the methylene chloride layer was isolated. The methylene chloride layer was dried over MgSO4 and evaporated under reduced pressure. 240 mL of hexane was added to the residue, and the remaining triphenylphosphine oxide was filtered off. Triphenylphosphine oxide was treated again with 240 mL of hexane. The pooled hexane fraction was evaporated under reduced pressure, and dibutylcarbodiimide was purified by distillation (boiling point, 82°C at 11 mbar). 13.6 g of dibutylcarbodiimide (yield: 67%) was isolated.

[0106] Step 2: Addition of 4-toluylmagnesium bromide to dibutylcarbodiimide: [ka] 0.666 g (4.32 mmol) of dibutylcarbodiimide was dissolved in 3 mL of tetrahydrofuran. The reaction mixture was cooled to -5 °C. While maintaining the temperature below 0 °C, 4.32 mL (4.32 mmol) of a 1 M tetrahydrofuran solution of p-tolylmagnesium bromide was added over 145 minutes. The reaction mixture was warmed to room temperature and the reaction was continued at room temperature for 16 hours. The reaction mixture was cooled to -5 °C and an additional 0.864 mL (0.864 mmol) of a 1 M tetrahydrofuran solution of p-tolylmagnesium bromide was added. The reaction mixture was warmed to room temperature. The reaction was continued at room temperature for 2 hours. The reaction mixture was cooled to -5 °C and an additional 0.432 mL (0.432 mmol) of a 1 M tetrahydrofuran solution of p-tolylmagnesium bromide was added. The reaction mixture was warmed to room temperature. The reaction was continued at room temperature for 2 hours. The reaction mixture was cooled to -5 °C and while maintaining the reaction temperature below 5 °C, 3 mL of methanol was added to the mixture. The precipitated salt was filtered off and washed with 20 mL of methyl t-butyl ether. The salt was treated with 20 mL of a 1 / 1 mixture of methylene chloride / methanol. The organic fractions were pooled and the solvent was removed under reduced pressure. 30 mL of water was added to the residue and the pH was adjusted to pH = 10 using 10 N NaOH solution. The mixture was extracted with 100 mL of methyl t-butyl ether. The methyl t-butyl ether fraction was isolated and the pH of the aqueous layer was adjusted to 12 using 10 N NaOH solution. The aqueous layer was extracted again with 100 mL of methyl t-butyl ether. The methyl t-butyl ether fractions were pooled, dried over MgSO4 and evaporated under reduced pressure. The crude amidine was purified by preparative column chromatography on a Varian Mega Bond Elut C18 column using methanol / 0.2 M ammonium acetate 70 / 30 as the eluent (TLC analysis on a Reveleris RP18 TLC plate with methanol / 1 M NaCl as the eluent, R f : 0.45). The pH of the pooled fractions was adjusted to 12 using 10 N NaOH solution. The pooled fractions were extracted with 250 mL of methyl t-butyl ether. The organic fraction was dried over MgSO4 and evaporated under reduced pressure. 0.463 g (yield: 39%) of purified amidine was isolated.

[0107] Step 3: Synthesis of model compound M1 [ka] 0.430 g (1.75 mmol) of amidine was dissolved in 3 mL of Proglyde DMM. 0.574 g (4.15 mmol) of K2CO3 and 0.67 g (3.49 mmol) of methyl tosylate were added, and the reaction mixture was heated to 76°C. The reaction was continued at 76°C for 17 hours. After 17 hours, an additional 0.326 g (1.75 mmol) of methyl tosylate was added. The reaction was continued at 76°C for an additional 2 hours. The reaction mixture was allowed to cool to room temperature. The precipitated salt was filtered off. The salt was washed with 7 mL of methyl t-butyl ether. The organic fraction was pooled, and the solvent was evaporated under reduced pressure. The residue was treated with 6 mL of water, and the pH was adjusted to 10 using a 10 N NaOH solution. The mixture was extracted with 30 mL of methyl t-butyl ether. The aqueous fraction was isolated and extracted with 20 mL of methylene chloride. The methylene chloride fraction was isolated, dried over MgSO4, and evaporated under reduced pressure. 0.531 g (yield: 64%) of model compound M1 was isolated (on a Uniplate (Reveleris RP18), and TLC analysis was performed using methanol / 1M NaCl as the eluent at 75 / 25 ratios). f :0.39). The molecular weight of model compound M1 was confirmed using TLC-MS as described above.

[0108] Synthesis of model compound M2 Model compound M2, having the structure shown below, was synthesized in three steps. [ka]

[0109] Step 1: Synthesis of dibutylcarbodiimide Dibutylcarbodiimide was prepared using the same method as for the model compound M1 described above.

[0110] Step 2: Addition of 2-mesitylmagnesium bromide to dibutylcarbodiimide: [ka]

[0111] 13.88 g (90 mmol) of dibutylcarbodiimide was dissolved in 45 mL of tetrahydrofuran. The reaction mixture was cooled to -5°C. While maintaining the temperature below 0°C, 90 mL (90 mmol) of 1 M tetrahydrofuran solution of 2-mesitylmagnesium bromide was added over 145 minutes. The reaction mixture was raised to room temperature, and the reaction was allowed to continue at room temperature for 16 hours. The reaction mixture was cooled to -5°C, and 70 mL of methanol was added to the mixture over 10 minutes. The precipitated salt was filtered off and washed with 50 mL of methyl t-butyl ether. The organic fraction was pooled and 700 mL of water was added. The pH was adjusted to 10.3 using a 10 NaOH solution. The mixture was extracted once with 1000 mL of methyl t-butyl ether and once with 500 mL of methyl t-butyl ether. The pooled organic fraction was extracted with 500 mL of water and dried over MgSO4. The solvent was removed under reduced pressure, and 21.5 g of the crude intermediate aminidine was isolated. The crude aminidine was purified using a Varian Mega Bond Elut C18 column with methanol / 0.2 M ammonium acetate as the eluent at a ratio of 70 / 30 (TLC analysis on a Revelleris RP18 TLC plate with methanol / 1 M NaCl as the eluent, R f (0.51). The pH of the pooled fraction was adjusted to 12 using a 10N NaOH solution. The pooled fraction was extracted with 250 mL of methyl t-butyl ether. The organic fraction was dried over MgSO4 and evaporated under reduced pressure. 17.8 g of purified amidine (yield: 72%) was isolated.

[0112] Step 3: Alkylation using methyl tosylate and synthesis of model compound M2 [ka] 5.49 g (20 mmol) of amidine was dissolved in 28 mL of Proglyde DMM. 6.58 g (47.6 mmol) of K2CO3 and 4.22 g (22 mmol) of methyl tosylate were added, and the reaction mixture was heated to 76°C. The reaction was continued at 76°C for 17 hours. The reaction mixture was allowed to cool to room temperature. The salt was filtered off and methyl t-butyl ether 80% was obtained. Washed with mL. The organic fraction was pooled and the solvent was removed under reduced pressure. 60 mL of water was added to the residue, and the pH was adjusted to 12 using a 10 N NaOH solution. The aqueous layer was extracted with 320 mL of methyl t-butyl ether. The organic fraction was dried over MgSO4 and evaporated under reduced pressure. 4.42 g of alkylated amidine (yield: 77%) was isolated (TLC analysis on a Revelleris RP18 TLC plate with methanol / 1 M NaCl as the eluent, 75 / 25, R f :0.33, TCL-MS analysis by the above method (MM=288). A second extraction was performed in the aqueous layer, this time using 200 mL of methylene chloride. The organic fraction was isolated, dried over MgSO4, and evaporated under reduced pressure. 1.4428 g of amidinium model compound M2 was isolated (TLC analysis on a Revelleris RP18 TLC plate with methanol / 1M NaCl as the eluent at 75 / 25, R f :0.33, TCL-MS analysis by the above method:MM=303 (this corresponds to the cation of model compound M2).

[0113] Synthesis of model compound M3 Model compound 3 was prepared to compare the stability of the cationic moiety according to the present invention in an alkaline medium with the stability of other highly stable cationic moieties disclosed in the prior art. For this purpose, the functional group disclosed by Fan et al. (ACS Macro Letters, 6(10), 1089-1093 (2017)) was selected. Model compound M3 was prepared having the same substituents and counterions as model compound M2. [ka]

[0114] CASRN29898-78-8 was prepared as disclosed by Fan et al. (ACS Macro Letters, 6(10), 1089-1093 (2017)).

[0115] Next, CASRN29898-78-8 was converted to model compound M3 by following the procedure below: 0.337 g (6 mmol) of potassium hydroxide was dissolved in 15 mL of DMSO. 1.015 g (3 mmol) of CASRN29898-76-8 was dissolved in 15 mL of DMSO and added to the potassium hydroxide solution over 5 minutes. The mixture was stirred at room temperature for 1 hour. 0.593 g (3.12 mmol) of methyl tosylate was added, and the reaction was continued at room temperature for 1 hour. The reaction was carried out on Merck Silica gel 60F. 254 The TLC-plate was monitored using TLC chromatography with n-hexane / ethyl acetate as the eluent at 80 / 20. After 1 hour, CASRN29898-78-8 was completely converted to an N-methylated compound (CASRN2131737-37-4, R f :0.38;TLC-MS analysis:mm=352). The reaction mixture was added to 240 mL of water containing 0.6 g of potassium hydroxide. The mixture was extracted with 90 mL of dibutyl ether. The organic fraction was washed with 50 mL of water, 50 mL of brine, and then 50 mL of water again. The organic fraction was dried over MgSO4 and evaporated under reduced pressure. 1.019 g of CASRN2131737-37-4 was isolated and dissolved in 15 mL of methylene chloride. 2.394 g (12.6 mmol) of methyl tosylate was added, and the reaction was continued at 30°C for 18 hours. The solvent was removed under reduced pressure, and preparative fractionation was performed on a Prochrom LC80 column using Kromasil C18 100A 10 μm as the stationary phase and methanol / 0.2 M ammonium acetate 70 / 30 as the eluent. Model compound M3 was purified by Lamb chromatography. 0.823 g (yield: 51%) of model compound M3 was isolated (TLC analysis on Whatman Partisil KC18F with methanol / 1M NaCl 70 / 30 as the eluent: R f:0.42; TLCMS analysis: Cation mm in positive mode: 367).

[0116] Stability of model compounds M1, M2, and M3 in alkaline solution. To compare the stability of model compounds M1 and M2 in alkaline solutions, 1 wt% solutions of both compounds were prepared with 2 M KOH. The mixtures were stored at 80°C, and the stability of the compounds was analyzed by TLC chromatography on a Uniplate Reveleris Rp18 plate using methanol / 1 M NaCl as the eluent at 80 / 20. To further confirm stability, TLC-MS analysis was performed on each sample to confirm its structure. The first sample was collected after 24 hours at 80°C.

[0117] After 24 hours, model compound M1 had completely decomposed, forming decomposed compounds D1 and D2, which were optionally in ionic form: [ka] [ka]

[0118] Model compound M2 remained completely intact even after 18 days at 80°C. No traces of degradation products were found. Structural integrity was further confirmed by TLC-MS. For example, no traces of dealkylation were found, which demonstrates the excellent alkali stability of the compound according to the present invention.

[0119] To compare the stability of model compounds M2 and M3, 2 wt% solutions of both compounds were prepared in 2 M potassium hydroxide. The solutions were stored at 80°C for 17 days and re-analyzed using a combination of TLC chromatography and mass spectrometry (TLC analysis using Whatman Partisil KC18F, eluent: methanol / 1 M NaCl 70 / 30).

[0120] Model compound M2 proved to be completely stable at 80°C for 17 days, but side reaction decomposition products were detectable in model compound M3 (R f (0.065). The structure of the degradation product was determined using mass spectrometry and was identified as CASRN2131737-37-4.

[0121] CASRN2131737-37-4 was formed by dealkylation of model compound M3 under the experimental conditions used, as illustrated in the scheme below. [ka]

[0122] From the above experiments, it can be concluded that the cationic compound according to the present invention shows improved stability in alkaline media compared to the prior art cationic moiety disclosed in the prior art.

[0123] Example 2 Starting from the amidine-functionalized precursor molecule APM-1, the amidinium-functionalized monomer AM-1 was synthesized. Subsequently, the alkali stability of AM-1 was evaluated.

[0124] Synthesis of Amidine-Functionalized Precursor Monomer APM-1 [ka] 1.28 g (10 mmol) of N,N-diisopropylcarbodiimide was dissolved in 1 mL of tetratidropuran. 12 mL (12 mmol) of 1 M THF solution of 2-mesitylmagnesium bromide was added over 90 minutes. During this time, the reaction temperature rose to 43°C. The reaction was continued at room temperature for an additional 30 minutes. 2.243 g (11 mmol) of 1,3-dibromopropane was added, and the reaction mixture was refluxed for 2 hours. The solvent was removed under reduced pressure, and 6 mL of dimethylformamide was added to the reaction mixture. 1.514 g (10 mmol) of sodium iodide and 2.43 g (11 mmol) of dibromopropane were added, and the reaction mixture was heated to 120°C. The reaction was continued for 1 hour. The solvent was removed under reduced pressure, and amidine was isolated by preparative column chromatography on a Prochrom LC80 column using Kromasil C18 100A, 10 μm as the stationary phase and methanol / 0.2 M ammonium acetate as the eluent at 70 / 30. 0.25 g of amidine (yield: 8.7%) was isolated (TLC analysis on a Revelleris RP18 TLC plate with methanol / 1 M NaCl as the eluent at 70 / 30, R f :0.26, TCL-MS analysis by the above method:MM:286).

[0125] Synthesis of Amidinium-Functionalized Monomer AM-1 [ka] 0.211 g (0.74 mmol) of amidine was dissolved in 1 mL of xylene. 0.435 g (2.26 mmol) of methyl tosylate was added, and the reaction mixture was heated to 135°C. The reaction was continued at 135°C for 6 hours. The reaction mixture was allowed to cool to room temperature, and the AM-1 phase separated from the medium. The xylene was removed, and the residue was dried under reduced pressure. The residue was dissolved in 1 mL of methylene chloride and precipitated with methyl t-butyl ether. AM-1 precipitated as an oily substance. The solvent was removed, and the residue was dried under reduced pressure. 0.245 g (yield: 70%) of AM-1 was isolated (TLC analysis on a Whatman RP18 plate with methanol / 1M NaCl eluent at 70 / 30: R f:0.42; TCL-MS analysis by the above method: MM:301, corresponding to the cation of AM-1).

[0126] Stability of AM-1 in alkaline solution A 1w% solution of AM-1 was prepared with 2M KOH, and this solution was stored at 80°C. The stability was analyzed using TLC analysis on a Whatman RP18 plate with methanol / 1M NaCl as the eluent. Each sample was analyzed by TLC-MS analysis using the method described above. After 47 days at 80°C, no signs of degradation were detected. The structural integrity of AM-1 was confirmed by TLC-MS analysis, demonstrating the excellent alkaline stability of the compound according to the present invention.

[0127] Example 3 The amidine-functionalized precursor monomer APM-2 was synthesized and polymerized to form the amidine-functionalized polymer APP-1. Subsequently, this polymer was quaternized to form the amidinium-functionalized polymer AP-1.

[0128] Synthesis of Amidine-Functionalized Precursor Monomer APM-2 [ka] 2.744 g (10 mmol) of the above amidine was dissolved in 12 mL of Proglyde DMM. 2.764 g (20 mmol) of K2CO3 was added, followed by 0.062 g of TEMPO and 1.526 g (10 mmol) of 4-vinylbenzyl chloride. The reaction mixture was heated to 120°C and the reaction was continued at 120°C for 17 hours. The reaction mixture was allowed to cool to room temperature, and the salt was filtered off. The salt was washed with 20 mL of methanol, and the pooled organic fraction was evacuated under reduced pressure. Vaporization was performed. 20 mL of water was added to the oily residue, and the pH was adjusted to 12 using a 10 N NaOH solution. The mixture was extracted with 60 mL of methyl t-butyl ether. The organic fraction was isolated, dried over MgSO4, and evaporated under reduced pressure. APM-2 was purified by preparative column chromatography using methanol / 0.2 M ammonium acetate as the eluent on a Varian Mega Bond Elut C18 column. 2.26 g (yield: 58%) of APM-2 was isolated (TLC analysis on a Revelleris RP18 TLC plate with methanol / 1 M NaCl as the eluent at 80 / 20, R f :0.36, TCL-MS analysis by the above method:MM:390)

[0129] Synthesis of amidine-functionalized precursor polymer APP-1 [ka] 1 g (2.56 mmol) of styrene-functionalized amidine was dissolved in 5 g of toluene. 1 g (9.6 mmol) of styrene was added. A solution was prepared by dissolving 23 mg (0.12 mmol) of WAKO V59 in 1 g of toluene. The reaction mixture was heated to 83°C, and the WAKO V59 toluene solution was injected into the reaction mixture. The needle was rinsed with an additional 1 g of toluene. Polymerization was continued at 83°C for 2 hours. 1 g of toluene containing an additional 23 mg (0.12 mmol) of WAKO V59 was added, and polymerization was continued at 83°C for 17 hours. 1 g of toluene containing an additional 12 mg (0.06 mmol) of WAKO V59 was added, and the reaction mixture was heated to 93°C. Polymerization was continued for an additional 2 hours. Monomer conversion was monitored using TLC chromatography (TLC analysis on a Revelleris RP18 TLC plate with methanol / 1M NaCl as the eluent at 80 / 20). After the third addition, only trace amounts of the remaining monomer were detectable. The reaction mixture was allowed to cool to room temperature, and the solvent was removed under reduced pressure. When 20 mL of methanol was added to the residue, APP-1 precipitated. APP-1 was isolated by filtration. The isolated polymer was treated with 30 mL of ethanol and isolated again by filtration. 1.32 g of APP-1 (yield: 66%) was isolated.

[0130] Synthesis of Amidinium-Functionalized Polymer AP-1 [ka] 1.160 g of APP-1 was dissolved in 4 mL of Proglyde DMM. A solution of 0.2 g (1.04 mmol) of methyl tosylate dissolved in 1 mL of Proglyde DMM was added, and the reaction mixture was heated to 125°C. Polymer transformation was monitored by TLC analysis (TLC analysis on a Revelleris RP18 TLC plate with methanol / 1M NaCl as the eluent, 70 / 30). After 16 hours at 125°C, no further detectable methyl tosylate was found. The tosylate ion, the counterion of the polymer, was clearly detectable. The structure of the counterion was confirmed by TLC-MS according to the method described above. An additional 0.2 g (1.04 mmol) of methyl tosylate was added, and the reaction was continued at 125°C for 5 hours. Traces of methyl tosylate were detectable during TLC analysis, but this was not further transformed. When the reaction mixture was allowed to cool to room temperature, the polymer separated from the reaction mixture. The solvent was removed, and the residue was dried under reduced pressure. When the residue was treated with 50 mL of methyl t-butyl ether, the polymer solidified. The polymer was isolated and dried. 1.06 g of AP-1 was isolated.

[0131] Example 4 Starting from APM-2, the amidinium-functionalized monomer AM-2 was synthesized and subsequently polymerized to form the amidinium-functionalized polymer AP-1', which has the same chemical formula as AP-1. This example demonstrates that there are different methods for obtaining amidinium-functionalized polymers.

[0132] Synthesis of Amidinium-Functionalized Monomer AM-2 [ka] 0.55 g (1.41 mmol) of APM-1 was dissolved in 5 mL of Proglyde DMM. 9 mg of TEMPO was added, followed by 0.551 g (2.82 mmol) of methyl tosylate. The reaction mixture was heated to 120°C and allowed to continue for 150 minutes. The reaction mixture was allowed to cool to room temperature, and the solvent was removed under reduced pressure. 25 mL of water was added to the oily residue, and the pH was adjusted to 12 using a 10 N NaOH solution. The mixture was extracted with 50 mL of methyl t-butyl ether. The methyl t-butyl ether fraction was extracted three times with 25 mL of water, and the pH was adjusted to alkaline by adding 400 μl of a 10 N NaOH solution. The pooled aqueous fraction was extracted with 200 mL of methylene chloride. The methylene chloride fraction was isolated, dried over MgSO4, and evaporated under reduced pressure. 0.37 g of AM-2 (yield: 46%) was isolated (TLC analysis on a Revelleris RP18 TLC plate with methanol / 1M NaCl eluent at 80 / 20 ratio: R f :0.35; TCL-MS analysis by the above method: MM of cations:405).

[0133] Synthesis of amidinium-functionalized polymer AP-1' by polymerization of amidinium-functionalized monomer AM-2 [ka] 0.35 g (0.61 mmol) of AM-2 and 0.35 g (3.36 mmol) of styrene were dissolved in 4.5 mL of toluene. A nitrogen stream was passed over the reaction mixture to remove oxygen. 12 mg (0.06 mmol) of WAKO V59 was dissolved in 0.5 mL of toluene and added. The reaction mixture was heated to 83°C with stirring. The reaction was continued at 83°C for 2 hours. After 2 hours, 0.5 mL of toluene containing an additional 12 mg (0.06 mmol) of WAKO V59 was added. Polymerization was continued at 83°C for 21 hours. The reaction was analyzed by TLC chromatography (on a Revelleris RP18 TLC plate, with methanol / 1M NaCl as the eluent, TLC analysis of AM-2 R) fMonitoring was performed using (0.35). After 21 hours at 83°C, AM-2 was completely converted to AP-1'. The solvent was removed under reduced pressure, and the residue was first treated with 20 mL of methyl t-butyl ether, followed by treatment with 30 mL of ethanol. Upon treatment with ethanol, AP-1' solidified and was isolated by filtration. 0.305 g of AP-1' (yield: 44%) was isolated.

Claims

1. an amidinium-functionalized compound, wherein the compound has a structure according to general formula I or general formula II. 【Chemistry 1】 【Chemistry 2】 During the ceremony ・R ５ and R ９ is any substituent other than hydrogen; ・R １ ~R ４ is independently selected from the group consisting of an alkyl group, an alkenyl group, an alkynyl group, an aralkyl group, an alkaryl group, an aryl group, and a heteroaryl group, or R １ and R ３ 、R １ and R ４ 、R １ and R ２ 、R ３ and R ４ 、R ２ and R ３ 、or R ２ and R ４ represents an atom necessary to form a 5- to 8-membered non-aromatic ring; ・R ６ ~R ８ The group is independently selected from the group consisting of hydrogen, alkyl groups, alkenyl groups, alkynyl groups, aralkyl groups, alkaryl groups, aryl or heteroaryl groups, halogen groups, ether groups, nitro groups, and amine groups, or R ５ and R ６ , R ６ and R ７ , R ７ and R ８ , or R ８ and R ９ One of these represents an atom necessary to form a five-membered to eight-membered ring; ・X － is an anion; Furthermore, during the ceremony ・R １ ~R ９ At least one of these has a polymerizable group or an atom necessary to link the amidinium group to the polymer. The compound characterized by the above.

2. X － These include iodide ions, bromide ions, chloride ions, fluoride ions, triiodide ions, hydroxide ions, carbonate ions, bicarbonate ions, cyanide ions, acetate ions, nitrate ions, sulfate ions, alkyl sulfate ions, perfluoroalkyl sulfonate ions, aryl sulfonate ions, perchlorate ions, tetrachloroaluminate ions, tetrafluoroborate ions, alkyl borate ions, phosphate ions, halophosphate ions, alkyl phosphate ions, trifluoromethanesulfonate ions, tosylate ions, and mesylate ions. The compound according to claim 1, selected from the group consisting of ions, alkyl carboxylate ions, tetrakis(3,5-bis(trifluoromethyl)phenyl)borate ions, bis(trifluoromethane)sulfonamides, and any combination thereof.

3. R ５ and R ９ The amidinium-functionalized compound according to claim 1 or 2, wherein is independently selected from alkyl groups and aryl groups.

4. R ５ and R ９ The amidinium-functionalized compound according to claim 3, wherein is independently selected from a methyl group and a phenyl group.

5. R １ ~R ９ The amidinium-functionalized compound according to any one of claims 1 to 4, wherein at least one of the members comprises a polymerizable group.

6. R １ , R ２ , R ３ , R ４ , or R ７ The amidinium-functionalized compound according to claim 5, wherein at least one of the groups comprises a polymerizable group selected from styrene, epoxy, oxetane, vinyl ether, or alkene.

7. A polymer comprising monomer units of the amidinium-functionalized compound according to claim 5 or 6.

8. The polymer according to claim 7, wherein the amidinium group of the amidinium-functionalized compound forms part of the polymer skeleton.

9. A dispersion comprising the polymer according to claim 7 or 8.

10. An anion exchange membrane comprising an amidinium-functionalized polymer as defined in claim 7 or 8.

11. The anion exchange film according to claim 10, coated with an electrode catalyst selected from nickel, molybdenum, copper, iron, ruthenium, iridium, or platinum.

12. The anion exchange film according to claim 11, wherein the coating further comprises the polymer according to claim 7 or 8.

13. An electrochemical apparatus comprising an anion exchange membrane according to any one of claims 10 to 12.

14. The device includes a water electrolyzer, a fuel cell, a CO ２ The electrochemical apparatus according to claim 13, which is an electrolytic cell, an electrodialysis machine, or a redox flow battery.

15. A method for preparing the polymer according to claim 7 or 8, the following: i. Polymerization of amidine-functionalized precursor compounds according to general formula III. 【Transformation 3】 During the ceremony R １ ~R ９ This is as defined in claim 5 or 6, ii. Obtain a cationic polymer by performing a quaternary modification step using an alkylating agent. Does it include, or i'. Polymerizing the amidinium-functionalized compound according to claim 5 or 6, The method, including the method described above.

16. Use of an anion exchange membrane according to any one of claims 10 to 12 for producing green hydrogen, green ammonia, or green steel.

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