Network polymers with molecular recognition and temperature responsiveness

Abstract

To provide a network polymer which can be used as a detection agent and a scavenger for a metal ion existing in water, in particular for an alkali metal ion, and further which makes it possible to remove (recover) a radioactive cesium ion difficult to be removed (recovered).SOLUTION: A temperature responsive polymer network film, to which metal cation recognition ability is imparted, is formed by introducing a crown ether to a temperature responsive polymer, is a network polymer which is a polymer with a repeating unit (1) derived from a polymerizable double bond-containing compound having a crown ether structure as a temperature responsive group and, if necessary, with a repeating unit (2) derived from another polymerizable compound randomly bonded to one another, and has a structure crosslinked at four positions derived from acrylamide groups in the repeating unit (1).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a network polymer having molecular recognition ability and temperature responsiveness, and in particular to a network polymer having molecular recognition ability and temperature responsiveness using a crown ether. [Background technology]

[0002] A temperature-responsive polymer is a polymer whose affinity for water changes with temperature. It has a lower critical temperature (LCST) and contains hydrophilic and hydrophobic segments in the molecule. It is hydrophilic at temperatures lower than the LCST and hydrophobic at temperatures higher than the LCST. For example, "poly(N-isopropylacrylamide) (PNIPAAm)" is one of the representative temperature-responsive polymers. PNIPAAm is a type of amphiphilic polymer that is water-soluble and hydrophobic, and when the temperature rises above its LCST (32°C), the hydrogen bonds between the amide groups in the side chains and the water molecules are broken, causing a shrinkage phenomenon in which a globule-like structure is formed. This phase transition from hydrophilic to hydrophobic causes the aqueous solution to become cloudy. Currently, applied research is being conducted on drug delivery systems (DDS) and cell culture by controlling the LSCT by changing the skeleton introduced into temperature-responsive polymers such as PNIPAAm. However, few of the thermoresponsive polymers such as PNIPAAm derivatives have molecular recognition capabilities, and none of them have the ability to preferentially or selectively incorporate specific metal ions such as cesium ions and change their own LCST. Among these, examples in which the crown ethers according to the present invention are used are given below. For example, in Patent Document 1, a temperature-responsive polymer is combined with a phosphate-based, amide-based, crown ether-based or other ligand to be used for separation of metal elements, in which the ligand is not a component in the molecule of the temperature-responsive polymer. Furthermore, Patent Document 2 describes a temperature-responsive polyrotaxane gel in which acrylamides or methacrylamides are bonded to a polyrotaxane network structure. Crown ethers or the like are used as cyclic molecules in the rotaxane structure. The temperature-responsive polyrotaxane gel controls sustained drug release by the expansion and contraction of the film, and does not capture cesium ions in cyclic molecules such as crown ethers. Patent Document 3 describes a thermoresponsive polymer gel having a rotaxane structure. Crown ethers and the like are used as cyclic molecules of the rotaxane structure. By heating, the affinity of water droplets on the film surface is controlled, and the gel is applied to heat-sensitive sensors, temperature-responsive adhesives, and the like. The gel does not have a molecular recognition function for metal ions, etc. In addition, Non-Patent Document 1 describes a polymer gel in which acrylamide (AAm), ethylene bisacrylamide (BIS), and DB24C8-containing acrylamide (DB24C8AAm) are monomers. Here, DB24C8 is dibenzo-24-crown-8, and a 24-membered crown ether is used. Ethylene bisacrylamide (BIS) serves as a crosslinking agent, and DB24C8AAm having a crown ether does not crosslink. Due to this structure, the film is highly hydrophobic and does not have temperature responsiveness. Although selective coordination to cesium ions is possible due to the crown ether, the cesium capture ability is low, even though the amount of crown ether relative to cesium ions is in large excess. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-138319 A [Patent Document 2] JP 2017-31258 A [Patent Document 3] JP 2010-159336 A [Non-patent literature]

[0004] [Non-Patent Document 1] Da-Ming Wang, Mamoru Matsushita et al. Polymer Gels Containing Dibenzo-24-Crown-8 ether Moieties for removal of Cesium Ionsfrom Aqueous Environment, Trans. Mat. Res. Soc. Japan, 44, 217-220(2019) Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention provides a temperature-responsive network polymer having metal cation recognition ability by introducing a crown ether into the temperature-responsive polymer, and provides the same as a detector and collector for metal ions, particularly alkali metal ions, present in water. It is also an object of the present invention to provide a network polymer that enables the removal (recovery) of radioactive cesium ions, which are difficult to remove (recover). [Means for solving the problem]

[0006] As a result of intensive research, the present inventors have found that a network polymer in which a monomer having a dibenzocrown ether and four (meth)acrylic groups is crosslinked to a temperature-responsive polymer such as "poly(N-isopropylacrylamide) (PNIPAAm)" can selectively detect and capture alkali metal ions such as cesium.

[0007] The present invention includes the following aspects. (1) A compound represented by formula (I). [ka] (In the formula, R represents a hydrogen atom or a methyl group; L's each independently represent a saturated or unsaturated, linear or branched hydrocarbon group having 2 to 20 carbon atoms which may have -O-, -CO-, -COO-, -OCO-, -CONH- or -NHCO-; X represents an oxygen atom or NH; n1 and n2 each independently represent an integer of 1 to 4. (2) A polymer in which a repeating unit derived from a polymerizable double bond-containing compound having a temperature-responsive group, a repeating unit derived from the compound described in (1), and, if necessary, a repeating unit derived from another polymerizable compound are randomly bonded, A network polymer having a structure crosslinked at four positions derived from (meth)acrylamide groups or (meth)acrylic ester groups in a repeating unit derived from the compound described in (1). (3) The network polymer according to (2), wherein the polymerizable double bond-containing compound having a temperature-responsive group is a (meth)acrylamide, a vinyl ether or a nitrogen-containing (meth)acrylate. (4) A metal collector containing the network polymer according to (2). (5) A metal detecting agent containing the network polymer according to (2). Effect of the Invention

[0008] The molecular recognition and temperature-responsive network polymer of the present invention undergoes a phase transition at a specific temperature (LCST) and turns white, and furthermore, shows a lower LCST by selectively incorporating metal ions into the crown ether. Therefore, metal ions can be detected by observing the change in LCST. Furthermore, the network polymer of the present invention having molecular recognition ability and temperature responsiveness can selectively detect, capture, and remove (recover) metal ions such as cesium by selecting the size of the crown ether. [Brief description of the drawings]

[0009] [Figure 1]1 is a photograph showing the process of whitening and shrinkage in water of the NIPAAm-co-TAA24C8 network polymer obtained in the example. [Diagram 2] FIG. 1 is a diagram showing the preparation process of a Cs+-containing NIPAAm-co-TAA24C8 network polymer in an example. [Diagram 3] 1 is a photograph showing the process of whitening and shrinkage of the NIPAAm-co-TAA24C8 network polymer obtained in the example in the presence of Cs+. [Figure 4] FIG. 1 is a schematic diagram showing the reason for the decrease in LCST in the presence of Cs+. [Diagram 5] FIG. 1 is a conceptual diagram showing why the LCST does not decrease in the presence of K+. [Figure 6] 1 is a graph showing the Cs+ ion recovery ability of the NIPAAm-co-TAA24C8 network polymer obtained in the examples, as measured by ICP. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] (Polymerizable double bond-containing monomer having dibenzocrown ether) The polymerizable double bond-containing monomer having dibenzocrown ether used in the present invention is a tetra(meth)acrylic compound represented by the following formula (I). It is used as a crosslinking agent for a network polymer. In the following, (meth)acrylamide means acrylamide or methacrylamide, and (meth)acrylic ester means acrylic ester or methacrylic ester. [ka] R represents a hydrogen atom or a methyl group; L's each independently represent a saturated or unsaturated, linear or branched hydrocarbon group having 2 to 20 carbon atoms which may have -O-, -CO-, -COO-, -OCO-, -CONH- or -NHCO-; X represents an oxygen atom or NH; n1 and n2 each independently represent an integer of 1 to 4.

[0011] The "saturated or partially unsaturated, linear or branched, hydrocarbon group having 2 to 20 carbon atoms, which may have -O-, -CO-, -COO-, -OCO-, -CONH- or -NHCO-" of L is -R1(OR2) m -, -R1(COOR2) m -, -R1(OCOR2) m -, -R1(CONHR2) m -or-R1(NHCOR2) m - represented by. Here, R1 and R2 are each independently a saturated or partially unsaturated, linear or branched hydrocarbon group, and R1 and R2 have 2 to 20 carbon atoms in total. m is an integer of 0 to 5. R2 in each repeating unit may be the same or different. R1 and R2 are alkylene groups such as a methylene group, a dimethylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, a heptamethylene group, an octamethylene group, a nonamethylene group, a decamethylene group, an undecamethylene group, a dodecamethylene group, a tridecamethylene group, a tetradecamethylene group, or a pentadecamethylene group; Examples of the alkylidene group include an ethylidene group, a propylidene group, an isopropylidene group, a sec-butylidene group, a tert-butylidene group, an n-pentylidene group, an n-hexylidene group, a decamethylidene group, and a pentadecamethylidene group.

[0012] Dibenzocrown ether is a type of crown ether, a cyclic polyether in which two benzene rings are condensed to a crown ether. Crown ethers include 12-crown-4, 15-crown-5, 18-crown-6, 21-crown-7, 24-crown-8, etc. For example, 18-crown-6 has 18 elements in the ring and contains 6 oxygen atoms. Dibenzocrown ethers are named by adding DB to the beginning. The characteristic of crown ethers is that they strongly recognize metal ions, especially alkali metal ions. When an alkali metal salt dissolves in water, the alkali metal ion undergoes water coordination (hydration). Crown ethers coordinate with the alkali metal ion, surrounding it in the same way that water coordinates. As the size of the crown ether ring increases, it selectively interacts with alkali metal ions that have a larger ionic radius. It can selectively recognize cations of a size close to that of the cation (Table 1).

[0013] [Table 1]

[0014] (Preparation of polymerizable double bond-containing monomer having dibenzocrown ether) The polymerizable double bond-containing monomer having a dibenzocrown ether of the present invention can be produced by a known production method using a dibenzocrown ether as a starting material, for example, by the method described in the Examples. Specifically, the following production methods can be mentioned. [ka] In the reaction formula, R, L, X, n1 and n2 are the same as those in formula (I). 1 represents OH or NH2.

[0015] The formylation of the benzene ring in the first step can be carried out, for example, by using trifluoroacetic acid (TFA) and hexamethylenetetramine (HMTA) or the like, and the X in the second step can be produced. 1 In the reaction with -L-NH2, X 1-L-NH2 can be produced by using a diamine compound represented by H2N-L-NH2 or an amine compound represented by HO-L-NH2 having an OH group at one end; hydrogenation of the imino group in the third step can be carried out by using NaBH4 or the like; and (meth)acrylamidation or (meth)acrylic esterification of the amino group in the third step can be carried out by reacting with (meth)acryloyl halide in the presence of a base such as triethylamine.

[0016] (Network Polymer) The network polymer of the present invention is a network polymer obtained by polymerizing a polymerizable double bond-containing monomer having a temperature-responsive group, a polymerizable double bond-containing monomer (crosslinking agent) having the above-mentioned dibenzocrown ether, and, if necessary, other polymerizable double bond-containing monomers. Here, "temperature-responsive polymer" refers to a polymer that undergoes a phase transition due to a change in temperature, changing its affinity for water. It has a lower critical temperature (LCST) at which the transition occurs, and has hydrophilic and hydrophobic segments in the molecule. It exhibits hydrophilicity (hydrated state) at temperatures lower than the lower critical temperature (LCST), and hydrophobicity (dehydrated state) at temperatures higher than the lower critical temperature (LCST). The term "monomer having a temperature-responsive group" refers to a monomer that exhibits temperature responsiveness when made into a polymer.

[0017] Examples of monomers having a temperature-responsive group include (meth)acrylamides, vinyl ethers, and nitrogen-containing (meth)acrylates. Specifically, there are the following examples: 1) (Meth)acrylamides N,N-Dimethylacrylamide N-ethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide (LCST of acrylamide polymer: 32°C), Nn-propyl (meth)acrylamide (LCST of acrylamide polymer: 21°C, LCST of methacrylamide polymer: 32°C), N-isopropyl(meth)acrylamide (LCST of acrylamide polymer: 32°C, LCST of methacrylamide polymer: 43°C), Nt-butylacrylamide, N,N-diethyl(meth)acrylamide, N-methyl-Nn-propyl (meth)acrylamide, N-tetrahydrofurfuryl(meth)acrylamide (LCST of acrylamide polymer: approx. 28°C, LCST of methacrylamide polymer: approx. 35°C) N-ethoxypropyl(meth)acrylamide (LCST of methacrylamide polymer: 38.5°C), N-ethoxyethyl (meth)acrylamide (LCST of acrylamide polymer: 35°C, LCST of methacrylamide polymer: 45°C), N-1-methyl-2-methoxyethyl (meth)acrylamide (LCST of acrylamide polymer: 33.5°C, LCST of methacrylamide polymer: 42.6°C), N-morpholinopropyl (meth)acrylamide, N-Methoxypropyl(meth)acrylamide, N-isopropoxypropyl (meth)acrylamide, N-isopropoxyethyl (meth)acrylamide, N-cyclopropyl(meth)acrylamide (LCST of acrylamide polymer: 43°C), N-methyl-N-ethyl (meth)acrylamide, N-methyl-N-isopropyl(meth)acrylamide, N-(meth)acryloylpiperidine, N-(meth)acryloylpyrrolidine, N-(meth)acryloylmorpholine, N-(2,2-dimethoxyethyl)-N-methyl(meth)acrylamide, N-1-methoxymethylpropyl(meth)acrylamide, N-di(2-methoxyethyl)(meth)acrylamide, N-2-Methoxyethyl-Nn-propyl(meth)acrylamide, N-2-methoxyethyl-N-ethyl(meth)acrylamide, N-2-Methoxyethyl-N-isopropyl(meth)acrylamide, N-methoxyethoxypropyl (meth)acrylamide, N-(1,3-dioxolan-2-yl)methyl(meth)acrylamide, N-Methyl-N-(1,3-dioxolan-2-yl)methyl(meth)acrylamide N-pyrrolidinomethyl(meth)acrylamide, N-piperidinomethyl(meth)acrylamide and the like. 2) Vinyl ethers 2-Methoxyethyl vinyl ether, 2-Ethoxyethyl vinyl ether 2-(2-methoxyethoxy)ethyl vinyl ether, 2-(2-ethoxyethoxy)ethyl vinyl ether, 2-(2-(2-methoxyethoxy)ethoxy)ethyl vinyl ether, 2-(2-(2-ethoxyethoxy)ethoxy)ethyl vinyl ether, 2-( 2-(2-(2-methoxyethoxy)ethoxy)ethoxy)ethyl vinyl ether, 4[2-(vinyloxy)ethoxy]benzoic acid, 4-(vinyloxy)-1-butanol, Isobutyl vinyl ether and the like. 3) Nitrogen-containing (meth)acrylates N,N-dimethylaminoethyl (meth)acrylate, N-methyl-N-ethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, N,N-dimethylaminopropyl (meth)acrylate, N-methyl-N-ethylaminopropyl (meth)acrylate, N,N-diethylaminopropyl (meth)acrylate, N-2-morpholinoethyl (meth)acrylate, N-2-morpholinoethoxyethyl (meth)acrylate, and the like. These may be used alone or in combination of two or more.

[0018] The network polymer of the present invention has the following repeating units (A), (B) and, if necessary, (C). (A) a repeating unit derived from a polymerizable double bond-containing monomer having a temperature-responsive group, (B) a repeating unit derived from a polymerizable double bond-containing monomer (crosslinking agent) having a dibenzocrown ether, and (C) Repeating units derived from other polymerizable double bond-containing monomers, as necessary The network polymer of the present invention has a structure in which the above-mentioned (A), (B) and, if necessary, (C) are randomly bonded and crosslinked at four positions derived from the (meth)acrylamide groups or (meth)acrylic ester groups in (B).

[0019] The molar ratio of the repeating units (A) and (B) in the network polymer varies depending on the LCST temperature, but can be in the range of (A):(B)=10 to 100:1, and is usually 20 to 30:1. When used, the switching unit of (C) is not particularly limited as long as it does not inhibit temperature responsiveness, but it can be in the range of (A):(C)=10-99:90-1, and is usually 30-80:70-20. Examples of other polymerizable double bond-containing monomers include ethylenic hydrocarbons, styrene hydrocarbons, and (meth)acrylates other than polymerizable double bond-containing monomers having a temperature-responsive group. Since the network polymer is an insoluble polymer, it is difficult to measure the average molecular weight. The lower limit solution temperature (LCST) of the network polymer of the present invention can be set to a desired temperature by appropriately selecting the polymerizable double bond-containing monomer having a temperature-responsive group, which is the raw material of the network polymer, or other polymerizable double bond-containing monomers, etc., depending on the application. Usually, it can be set in the range of 0 to 60°C, and can be set, for example, to 10 to 40°C.

[0020] The network polymer of the present invention has the following characteristics. 1) It is a free-standing three-dimensional network polymer film using DB24C8, which has four double bonds, as a crosslinking agent. 2) It is a (semi)transparent gel-like film in water. 3) The film turns white at a specific temperature (lower critical solution temperature; LCST) (temperature can also be adjusted) 4) Selective response to metal ions such as cesium ions (lowering of LCST)

[0021] (Adjustment of network polymer) The network polymer of the present invention can be prepared by any method, but the method is not particularly limited. The network polymer can be obtained by polymerizing a polymerizable double bond-containing monomer having a temperature-responsive group, a polymerizable double bond-containing monomer (crosslinking agent) having the above-mentioned dibenzocrown ether, and, if necessary, other polymerizable double bond-containing monomers. The polymerization can be generally carried out by a radical polymerization reaction, for example, a method of exposing to heat or light, a method of adding other active species, etc., and a polymerization initiator, a stabilizer for reactive active species, etc. may be added during the polymerization reaction. Here, the mixing ratio of the polymerizable double bond-containing monomer having a temperature-responsive group and the polymerizable double bond-containing monomer having a dibenzocrown ether (crosslinking agent) is 10 to 100:1, usually 20 to 30:1, in terms of molar ratio. The reaction conditions are not particularly limited, but the reaction is usually carried out in a polar solvent such as acetonitrile, N,N-dimethylformamide, dimethylsulfoxide, methanol, alcohol, etc. (a mixed solution is also acceptable) at room temperature to the boiling point of the solvent for about 1 to about 24 hours.

[0022] The polymerization initiator used may be any known one, and examples thereof include azo initiators such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylpropionamidine) disulfate, 2,2'-azobis(2-methylpropionamidine) dihydrochloride, 2,2'-azobis(2-amidinopropane) dihydrochloride, and 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride; persulfate initiators such as potassium persulfate and ammonium persulfate; and peroxide initiators such as benzoyl peroxide, t-butyl hydroperoxide, and hydrogen peroxide. In particular, photopolymerization initiators include acetophenone, acetophenone benzyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-1,2-diphenylethan-1-one, xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, triphenylamine, carbazole, 3-methylacetophenone, benzophenone, 4-chlorobenzophenone, 4,4'-dimethoxybenzophenone, 4,4'-diaminobenzophenone, benzoin propyl ether, benzoin ethyl ether, benzyl dimethyl ketal, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and the like. Examples of the polymerization initiator include pan-1-one, thioxanthone, diethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1,4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, oligo(2-hydroxy-2-methyl-1-(4-(1-methylvinyl)phenyl)propanone), etc. These polymerization initiators may be used alone or in combination of two or more.

[0023] After polymerization, the resulting network polymer can be used in the form of a gel, particles, blocks, film, or the like. The film can be obtained by carrying out polymerization on a substrate such as glass, drying, and then peeling it off from the substrate.

[0024] (Applications of network polymers) The water-soluble gel of the network polymer of the present invention undergoes a phase transition at a specific temperature and turns white, and further exhibits a lower LCST by selectively incorporating metal ions into the crown ether. Therefore, metal ions can be detected by observing the change in LCST. Crown ethers coordinate with metal ions, particularly alkali metal ions, so as to surround the alkali metal ions, and as the size of the crown ether ring increases, they can selectively incorporate alkali metal ions with larger ionic radii. As shown in Table 1 above, crown ethers can selectively recognize cations with sizes close to the inner hole of the ring. By changing the size of the crown ether, it is possible to selectively capture metal ions, and by taking advantage of the property that the LCST changes upon the capture of metal ions, it can be used as a detector or collector for metal ions, particularly alkali metal ions, in water. The network polymer of the present invention can also be used to detect and recover radioactive cesium, a hazardous substance that may leak during a nuclear accident.

[0025] The present invention will be described in more detail below with reference to examples, but the technical scope of the present invention is not limited to these examples. EXAMPLES

[0026] (Reagents and Solvents) Methanol, hexane, diethyl ether, and dichloromethane were used as first-grade commercial products. Triethylmaine was from Sigma-Aldrich Japan. TrifluoroaceticAcid, 1,2-Bis(2-aminoethoxy)ethane, acrylic chloride, cesium bis(trifluoromethane-sulfonyl)imide, and potassium bis(fluorosulfonyl)imide were from Tokyo Chemical Industry Co., Ltd. Cesium bis(trifluoromethane-sulfonyl)imide and potassium bis(fluorosulfonyl)imide were dissolved in water and used as aqueous solutions. Hexamethylenetetramine was from Kishida Chemical Co., Ltd. Crownether / dibenzo-24-crown-8 (DB24C8) was from Wako Pure Chemical Industries, Ltd. (Measuring Equipment) 1 H NMR (500 MHz) spectra were measured in deuterated chloroform using tetramethylsilane (TMS) as the internal standard on a JMN-LA500 (JEOL Ltd.). The UV irradiator (light source: halogen lamp) was a J-cure1500 (JATEC Co., Ltd.).

[0027] (1) Synthesis of crosslinker (TAA24C8) 1) Synthesis of DFB24C8 (Compound No. 1) [ka]

[0028] In a 500mL eggplant flask, add DB24C8 (2.05g, 4.56×10 3After adding 1.2 mmol), hexamethylenetetramine (HMTA) (3.78 g), and trifluoroacetic acid (TFA) (48.0 mL), the mixture was stirred for about 20 hours at 60°C in a reflux oil bath. The mixture was then extracted with water (10.0 mL) and dichloromethane, filtered, and concentrated. After washing, the mixture was filtered and naturally dried to obtain a brown solid. This was used in the next reaction without purification. (Yield 10.3 g, yield 90.8%) 1 H-NMR (CDCl3) δ (ppm fromTMS): 9.83-9.78 (s, 2H, Ph-C H O), 7.43-6.85 (d, 6H, Ph), 4.31-3.54 (t,24H, -OC H 2-C H 2-OC H 2-C H 2-OC H 2-C H 2-O-).

[0029] 2) Synthesis of AE DB24C8 (Compound No. 2) [ka]

[0030] Add 1,2-Bis(2-aminoethoxy)ethane (BAE) (0.735 g, 4.96 × 10 -3 mol), DFB24C8 (0.500g, 9.91×10 -4 The product was dissolved in MeOH:CH2Cl2 = 1:3 (5 mL) and stirred for 20 hours, then concentrated to give a brown liquid, which was used in the next reaction without purification.

[0031] 3) Synthesis of AE DB24C8-red (Compound No. 3) [ka]

[0032] In a 100 mL eggplant flask, add AE DB24C8 (in MeOH:CH2Cl2=1:3), NaBH4 (0.196 g, 4.96 × 10 3 mol) was added and stirred in an ice bath for 20 hours. After that, it was washed with saturated saline and concentrated to obtain a brown liquid (yield 0.25 g, 80.8%). 1 H-NMR (CDCl3) δ (ppm .fromTMS): 6.91-6.77 (d, 6H, Ph), 3.76-3.68 (s, 4H, Ph-CH2-N H ),2.82-2.71 (s, 4H, Ph-CH2-NH-C H 2), 3.68-3.54 (s,4H, Ph-CH2-NH-CH2-C H 2-OC H 2-C H 2),3.54-3.44 (s, 4H, Ph-CH2-NH-CH2-CH2-O-CH2-CH2-OC H 2),2.93-2.83 (s, 4H, Ph-CH2-NH-CH2-CH2-O-CH2-CH2-O-CH2-C H 2), 4.20-3.77 (t, 24H, -OC H 2-C H 2-OC H 2-C H 2-OC H 2-C H 2-O-).

[0033] 4) Synthesis of TAA24C8 (Compound No. 4) [ka]

[0034] AE DB24C8-red (0.202 g, 2.63 × 10 4 mol), Triethylamine (0.200g, 1.98×10 -3After adding 0.126g of acryloylchloride (1.39×10 mol) and stirring, -3 mol) was added and the mixture was stirred in an ice bath for 20 hours and concentrated. It was then washed with 1 mol / L NaOH aq (100 mL), filtered, and concentrated to obtain a brown viscous liquid (yield 0.47 g, 82.7%). 1 H-NMR (CDCl3) δ (ppm .fromTMS): 6.99-6.64 (t, 6H, Ph), 4.69-4.53 (s, 4H, Ph-C H 2-),3.72-3.39 (t, 24H, Ph-CH2-NH-C H 2-C H 2-OC H 2-C H 2-OC H 2-C H 2), 4.19-3.72 (t, 24H, -OC H 2-C H 2-OC H 2-C H 2-OC H 2-C H 2-O-),6.64-5.52 (t, 6H, -N-CO-C H -C H 2-, -NH-CO-C H -C H 2-).

[0035] (2) Synthesis of network polymer (NIPAAm-co-TAA24C8) [ka]

[0036] Add N-isopropylacrylamide (NIPAAm) (0.242g, 2.06×10 3 mol), N,N-dimethylformamide (DMF) (1.00mL), TAA24C8 (0.09g, 1.03×10 -4mol) was added and mixed. Furthermore, the solution to which the photoinitiator benzophenone (appropriate amount) was added was applied to a glass plate and exposed to ultraviolet light using a halogen lamp as a UV irradiator light source. After that, it was washed with H2O, the film was peeled off from the glass plate, and then dried in a dryer for 24 hours to obtain a semi-transparent film. (Yield 0.115g, 38.5%)

[0037] (LCST measurement of NIPAAm-co-TAA24C8 network polymer in water) The dried NIPAAm-co-TAA24C8 network polymer was immersed in water for about 1 hour, and then heated in water from about 20°C to 30°C to measure the LCST. As a result, the NIPAAm-co-TAA24C8 network polymer was translucent and swollen at about 20°C, but turned white and shrunk when it reached about 28°C. The shrinkage rate at that time was about 33%. Figure 1 shows the process of whitening and shrinkage of the NIPAAm-co-TAA24C8 network polymer.

[0038] Compared with the LCST of poly N-isopropilacrylamide (PNIPAAm), the LCST of the NIPAAm-co-TAA24C8 network polymer was found to be reduced by approximately 4°C. The reason why the LCST of the NIPAAm-co-TAA24C8 network polymer is lower than that of normal NIPAAm is that DB24C8 used as a crosslinker has two benzene rings, which are hydrophobic groups, and the entire DB24C8 crosslinker is hydrophobic. Therefore, when this DB24C8 is introduced into PNIPAAm, the hydrophobicity of the NIPAAm-co-TAA24C8 network polymer increases, so that even a small amount of water molecules removed from the amide groups of the PNIPAAm side chains makes it easier for a phase transition to occur. This is thought to be why the LCST is lower.

[0039] (NIPAAm-co-TAA24C8 network polymer Cs + LCST measurement in the presence of As shown in Figure 2, the dried NIPAAm-co-TAA24C8 network polymer (DB24C8:Cs+ =1:2) + After immersion in the aqueous solution for 1 hour, the sample was heated from about 20°C to 30°C and the LCST was measured. Figure 3 shows Cs + The whitening and shrinkage of the NIPAAm-co-TAA24C8 network polymer in the presence of 1,2-dichlorophenyl ether (PAA) is shown. Cs + In the presence of ethanol, the membrane was translucent and swollen at about 20°C, whereas it turned white and shrunk at about 26°C, resulting in a LCST of about 26°C, which is about 2°C lower than the LCST in water.

[0040] Cs + The reason for the decrease in the LCST in the presence of β-lactamase may be as follows. As shown in Figure 4, first, Cs + In the absence of Cs, the ether oxygen in the crown ether is bound to a water molecule, making the crown ether easily hydrated. + In the presence of Cs, the crown ether + The coordination of Cs with the ether oxygen in the crown ether + The interaction with the ether oxygen becomes stronger, and the bond between the ether oxygen and water molecules becomes difficult. In other words, in addition to the high hydrophobicity of the benzene ring in DB24C8, the Cs of the crown ether + The increase in hydrophobicity of the ether ring due to coordination is thought to be the cause of the further decrease in LCST.

[0041] For comparison, NIPAAm-co-TAA24C8 network polymer was used. + LSCT was also measured in the presence of IL-1. As a result, K + The LCST in the presence of + The LCST was the same as that in water without K. + The reason why the LCST did not decrease in the presence of K was that the ring size of the crown ether in TAA24C8 was large, as shown in Figure 5. +The ether oxygen in the crown ether does not coordinate sufficiently, and K + Since no interaction occurred with K + It is considered that the LCST did not decrease compared to the case in water in the absence of acetylcholine.

[0042] (Cs of NIPAAm-co-TAA24C8 network polymer by ICP measurement) + Recovery evaluation) Water temperature 10℃ Cs + A film of NIPAAm-co-TAA24C8 network polymer containing an equal amount of crown ether units was added to an aqueous solution of 3000 ppm concentration, and Cs + After immersion for 1 hour without stirring, the recovery capacity of Cs + The film was taken out of the solution, and the concentration of the solution was evaluated by elemental analysis using inductively coupled plasma (ICP) emission spectroscopy. As a result, as shown in Figure 6, the Cs concentration in the solution was + The concentration was reduced by about 50% (Cs + 50% recovery was successful.

Claims

1. A compound represented by formula (I). (In the formula, R represents a hydrogen atom or a methyl group; L each independently represents a saturated or unsaturated, linear or branched hydrocarbon group having 2 to 20 carbon atoms which may have -O-, -CO-, -COO-, -OCO-, -CONH-, or -NHCO-; X represents an oxygen atom or NH; n1 and n2 each independently represent an integer from 1 to 4.

2. A polymer in which a repeating unit derived from a polymerizable double bond-containing compound having a temperature-responsive group, a repeating unit derived from the compound according to claim 1, and, if necessary, a repeating unit derived from another polymerizable compound are randomly bonded, A network polymer having a structure crosslinked at four positions derived from (meth)acrylamide groups or (meth)acrylic ester groups in a repeating unit derived from the compound according to claim 1.

3. 3. The network polymer according to claim 2, wherein the polymerizable double bond-containing compound having a temperature-responsive group is a (meth)acrylamide, a vinyl ether or a nitrogen-containing (meth)acrylate.

4. A metal collector comprising the network polymer according to claim 2 .

5. A metal detecting agent comprising the network polymer according to claim 2 .

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