Polyallylamine with aromatic compound introduced

Abstract

To provide a novel polyallylamine derivative applicable as an absorption or desorption agent of carbon dioxide.SOLUTION: A polyallylamine includes a repeating unit expressed by a following general formula (1): [In the formula, n denotes a number 1 to 5 and R independently denotes a halogen atom or a hydroxy group].SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polyallylamine having an aromatic compound introduced therein. [Background technology]

[0002] The use of amine compounds as carbon dioxide absorbents, desorbents, etc. has been investigated. For example, Patent Document 1 describes a method for adsorbing gases, particularly acidic gases, onto a monodisperse spherical aminomethylated polymer. Furthermore, Patent Document 2 discloses a method for producing polyallylbenzamide-graphene hydrogel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-52340 [Patent Document 2] Chinese Patent Application Publication No. 201910760594 Summary of the Invention [Problem to be solved by the invention]

[0004] However, there is room for improvement in the ability of conventional amine compounds such as those described in Patent Documents 1 and 2 to absorb or desorb carbon dioxide. Therefore, an object of the present invention is to provide a novel polyallylamine derivative that can be used as a carbon dioxide absorbent or desorbent. [Means for solving the problem]

[0005] The present invention provides polyallylamine described in the following [1] to [4].

[0006] [1] Polyallylamine having a repeating unit represented by the following general formula (1): In general formula (1), n is a number from 1 to 5, and each R independently represents a halogen atom or a hydroxyl group.

[0007] [ka]

[0008] In the general formula (1), -(R) n means that n Rs are bonded to the benzene ring.

[0009] The polyallylamine can be used as a carbon dioxide absorber or desorber. The polyallylamine has a sufficiently large carbon dioxide absorption capacity. The carbon dioxide absorption capacity determined by the carbon dioxide absorption capacity evaluation described below can be, for example, about 9 to 17 times that of polyallylamine composed only of 3-aminopropylene repeating units.

[0010] Furthermore, carbon dioxide absorbents and the like that use low-molecular-weight amine compounds such as monoethanolamine can produce a foul odor due to the evaporation of the low-molecular-weight amine compounds, but the polyallylamine provided by the present invention is a polymer, and therefore the foul odor can be reduced.

[0011] Furthermore, since the polyallylamine can repeatedly absorb and desorb carbon dioxide, the polyallylamine can be a reusable carbon dioxide absorption or desorption agent.

[0012] [2] The polyallylamine according to [1], wherein the halogen atom is a fluorine atom.

[0013] The polyallylamine in which the halogen atom is a fluorine atom has a larger carbon dioxide absorption capacity.

[0014] [3] The polyallylamine according to [1] or [2], wherein the repeating unit represented by the general formula (1) has a skeleton selected from the group consisting of a 4-fluorobenzamide skeleton, a 4-hydroxybenzamide skeleton, a 2,3,5,6-tetrafluorobenzamide skeleton, a pentafluorobenzamide skeleton, and a 2,3,5,6-tetrafluoro-4-hydroxybenzamide skeleton.

[0015] Such polyallylamine has an even greater carbon dioxide absorption capacity.

[0016] [4] The polyallylamine according to any one of [1] to [3], wherein the number of repeating units represented by the formula (1) is 10 to 95% based on the total number of repeating units. [Effects of the Invention]

[0017] According to the present invention, a novel polyallylamine derivative that can be used as an absorbent or desorbent for carbon dioxide can be provided. [Brief explanation of the drawings]

[0018] [Figure 1] 1H-NMR spectrum of polyallylamine having a 4-fluorobenzamide skeleton. [Figure 2] 1 is an IR spectrum of polyallylamine having a 4-fluorobenzamide skeleton. [Figure 3] 1H-NMR spectrum of polyallylamine having a 4-hydroxybenzamide skeleton. [Figure 4] 1 is an IR spectrum of polyallylamine having a 4-hydroxybenzamide skeleton. [Figure 5] 1H-NMR spectrum of polyallylamine having a 2,3,5,6-tetrafluoro-4-hydroxybenzamide skeleton. [Figure 6] 1 is an IR spectrum of polyallylamine having a 2,3,5,6-tetrafluoro-4-hydroxybenzamide skeleton. [Figure 7] 1H-NMR spectrum of polyallylamine having a 2,3,5,6-tetrafluorobenzamide skeleton. [Figure 8] 1 is an IR spectrum of polyallylamine having a 2,3,5,6-tetrafluorobenzamide skeleton. [Figure 9]1H-NMR spectrum of polyallylamine having a pentafluorobenzamide skeleton. [Figure 10] 1 is an IR spectrum of polyallylamine having a pentafluorobenzamide skeleton. [Figure 11] Graphs showing the relationship between the chemical equivalent of substituted benzoic acid and the ratio of the number of repeating units represented by general formula (1) based on the total number of repeating units, where (a) is a graph showing the relationship between the chemical equivalent of 4-fluorobenzoic acid and the ratio, (b) is a graph showing the relationship between the chemical equivalent of 4-hydroxybenzoic acid and the ratio, (c) is a graph showing the relationship between the chemical equivalent of 2,3,5,6-tetrafluorobenzoic acid and the ratio, (d) is a graph showing the relationship between the chemical equivalent of pentafluorobenzoic acid and the ratio, and (e) is a graph showing the relationship between the chemical equivalent of 2,3,5,6-tetrafluoro-4-hydroxybenzoic acid and the ratio. [Figure 12] These are the adsorption and desorption isotherms of various polyallylamine. (a) is the adsorption and desorption isotherm of polyallylamine having a 4-fluorobenzamide skeleton, (b) is the adsorption and desorption isotherm of polyallylamine having a 4-hydroxybenzamide skeleton, (c) is the adsorption and desorption isotherm of polyallylamine having a 2,3,5,6-tetrafluorobenzamide skeleton, (d) is the adsorption and desorption isotherm of polyallylamine having a pentafluorobenzamide skeleton, (e) is the adsorption and desorption isotherm of polyallylamine having a 2,3,5,6-tetrafluoro-4-hydroxybenzamide skeleton, and (f) is the adsorption and desorption isotherm of unsubstituted polyallylamine. [Figure 13] 1 is a graph showing the carbon dioxide absorption capacity of various polyallylamines and unsubstituted polyallylamines. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, embodiments of the present disclosure will be described in detail.

[0020] The polyallylamine according to this embodiment has a repeating unit represented by the above-mentioned general formula (1). That is, the polyallylamine according to this embodiment is a homopolymer comprising a repeating unit represented by the general formula (1), or a copolymer comprising a repeating unit represented by the general formula (1) and a 3-aminopropylene repeating unit.

[0021] In general formula (1), n is a number from 1 to 5, and each R independently represents a halogen atom or a hydroxyl group. n may be a number from 2 to 5, 3 to 5, 4 to 5, or 5. R may contain 1 or more, 2 or more, 3 or more, 4 or more, or 5 halogen atoms. When multiple halogen atoms are present as R, the carbon dioxide adsorption capacity becomes larger, and this tendency becomes more pronounced as the number of halogen atoms increases. The halogen atom represented by R may be a fluorine atom.

[0022] The repeating unit represented by general formula (1) may have a skeleton selected from the group consisting of a 4-fluorobenzamide skeleton, a 4-hydroxybenzamide skeleton, a 2,3,5,6-tetrafluorobenzamide skeleton, a pentafluorobenzamide skeleton, and a 2,3,5,6-tetrafluoro-4-hydroxybenzamide skeleton. When the repeating unit represented by general formula (1) has such a group, the carbon dioxide adsorption capacity of the polyallylamine according to this embodiment is increased.

[0023] Here, embodiments in which the repeating unit represented by general formula (1) "has a 4-fluorobenzamide skeleton" include embodiments in which the amino group in the repeating unit forms a reaction product with "4-fluorobenzene having a group that reacts with an amino group to form an amide group," such as 4-fluorobenzoic acid or 4-fluorobenzoyl halide, resulting in the introduction of a "4-fluorobenzamide skeleton." The same applies to a 4-hydroxybenzamide skeleton, a 2,3,5,6-tetrafluorobenzamide skeleton, a pentafluorobenzamide skeleton, and a 2,3,5,6-tetrafluoro-4-hydroxybenzamide skeleton. That is, the embodiment "having a 4-hydroxybenzamide skeleton" is an embodiment in which a reaction product is formed with "4-hydroxybenzene having a group that reacts with an amino group to form an amide group" such as 4-hydroxybenzoic acid or 4-hydroxybenzoyl halide, the embodiment "having a 2,3,5,6-tetrafluorobenzamide skeleton" is an embodiment in which a reaction product is formed with "2,3,5,6-tetrafluorobenzene having a group that reacts with an amino group to form an amide group" such as 2,3,5,6-tetrafluorobenzoic acid or 2,3,5,6-tetrafluorobenzoyl halide, and the embodiment "having a pentafluorobenzamide skeleton" is an embodiment in which a reaction product is formed with "2,3,5,6-tetrafluorobenzene having a group that reacts with an amino group to form an amide group" such as 2,3,5,6-tetrafluorobenzoic acid or 2,3,5,6-tetrafluorobenzoyl halide. The embodiment "having a 2,3,5,6-tetrafluoro-4-hydroxybenzamide skeleton" includes a reaction product formed with "pentafluorobenzene having a group that reacts with an amino group to form an amide group," such as pentafluorobenzoic acid or pentafluorobenzoic acid halide, and the embodiment "having a 2,3,5,6-tetrafluoro-4-hydroxybenzamide skeleton" includes a reaction product formed with "2,3,5,6-tetrafluoro-4-hydroxybenzene having a group that reacts with an amino group to form an amide group," such as 2,3,5,6-tetrafluoro-4-hydroxybenzoic acid or 2,3,5,6-tetrafluoro-4-hydroxybenzoic acid halide. Chloride is preferred as the halide.

[0024] The polyallylamine according to this embodiment may have a plurality of repeating units represented by general formula (1). In this case, the plurality of repeating units represented by general formula (1) may be the same or different.

[0025] In the polyallylamine according to this embodiment, the number of repeating units represented by general formula (1) may be 10 to 95% of the total number of repeating units, and from the viewpoint of further improving the carbon dioxide absorption capacity, it is preferably 12 to 65%, more preferably 15 to 35%. The total number of repeating units is the sum of the number of repeating units represented by the above formula (1) and the number of 3-aminopropylene repeating units (the same applies hereinafter).

[0026] When the repeating unit represented by general formula (1) is a repeating unit having a 4-fluorobenzamide skeleton, the number of repeating units represented by general formula (1) in the polyallylamine according to this embodiment may be 10 to 50% based on the total number of repeating units.

[0027] When the repeating unit represented by general formula (1) is a repeating unit having a 4-hydroxybenzamide skeleton, the number of repeating units represented by general formula (1) in the polyallylamine according to this embodiment may be 10 to 50% based on the total number of repeating units.

[0028] When the repeating unit represented by general formula (1) is a repeating unit having a 2,3,5,6-tetrafluorobenzamide skeleton, the number of repeating units represented by general formula (1) in the polyallylamine according to this embodiment may be 15 to 90% based on the total number of repeating units.

[0029] When the repeating unit represented by general formula (1) is a repeating unit having a pentafluorobenzamide skeleton, the number of repeating units represented by general formula (1) in the polyallylamine according to this embodiment may be 15 to 90% based on the total number of repeating units.

[0030] When the repeating unit represented by general formula (1) is a repeating unit having a 2,3,5,6-tetrafluoro-4-hydroxybenzamide skeleton, the number of repeating units represented by general formula (1) in the polyallylamine according to this embodiment may be 5 to 70% based on the total number of repeating units.

[0031] In the polyallylamine according to this embodiment, the ratio of the number of repeating units represented by the general formula (1) based on the total number of repeating units is determined by proton nuclear magnetic resonance ( 1 The NMR spectrum is determined by the following method. First, the polyallylamine is subjected to proton nuclear magnetic resonance using dimethyl sulfoxide-d6 as the measurement solvent, tetramethylsilane as the internal standard, and a frequency of 400 MHz to obtain a proton nuclear magnetic resonance spectrum. The obtained proton nuclear magnetic resonance spectrum is shown in Figure 1. Note that Figure 1 shows the structure of a polyallylamine in which the repeating unit represented by general formula (1) has a 4-fluorobenzamide skeleton. 1 The H-NMR spectrum is then obtained. Next, from the proton nuclear magnetic resonance spectrum, the peak area of the hydrogen atom of the amide bond of the repeating unit represented by general formula (1) (d in the case of FIG. 1) and the sum of the peak areas of the hydrogen atoms corresponding to a, b, a', b', and d' shown in the example of FIG. 1 are calculated. The above ratio is then calculated using the following formula (A). In the following formula (A), x represents the above ratio. x: (5-2x) = (peak area of hydrogen atom d): (sum of peak areas of hydrogen atoms a, b, a', b', and d')...(A)

[0032] The weight-average molecular weight (Mw) of the polyallylamine may be, for example, 500 to 100,000 or 1,000 to 15,000. The weight-average molecular weight of the polyallylamine is determined by gel permeation chromatography (GPC) using a Hitachi high-performance liquid chromatograph. Specifically, the eluent flow pump is a Hitachi L-2130 inert pump, the detector is a Hitachi Chromaster® 5450, and the columns are a dual-connected Asahi Pack aqueous gel filtration type GS-220HQ (molecular weight exclusion limit: 3,000) and GS-620HQ (molecular weight exclusion limit: 2,000,000). The sample is adjusted to a concentration of 0.5 g / 100 mL with the eluent, and 20 μL of the sample is used. The eluent is a 0.4 mol / L aqueous sodium chloride solution. The column temperature is 30°C, and the flow rate is 1.0 mL / min. A calibration curve was prepared using polyethylene glycols with molecular weights of 106, 194, 420, 615, 1010, 1970, 3930, 7920, 12140, 18380, 21300, 25240, 50630, 77360, 116300, 199800, 278000, 454000, and 895500 as standard samples, and the weight-average molecular weight (Mw) of the copolymer was determined based on the calibration curve. The ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn) (Mw / Mn) was approximately 1.0 to 15.0.

[0033] The polyallylamine according to the present embodiment has a sufficiently large carbon dioxide adsorption capacity. Here, "sufficiently large carbon dioxide absorption capacity" means that the carbon dioxide absorption capacity determined by evaluating the carbon dioxide absorption capacity of the polyallylamine is greater than that of a polyallylamine comprising 3-aminopropylene repeating units that has the same number of repeating units as the polyallylamine (hereinafter, sometimes referred to as "unsubstituted polyallylamine").

[0034] In evaluating the carbon dioxide absorption capacity, the carbon dioxide absorption capacity is determined by subtracting the amount of water contained in the polyallylamine from the amount of carbon dioxide absorbed when the equilibrium pressure of carbon dioxide is equal to the saturated vapor pressure in the adsorption / desorption isotherm of the polyallylamine according to this embodiment at 25°C. The adsorption / desorption isotherm may be determined specifically by a method described in the Examples. The water content may be determined by measuring the mass loss when the polyallylamine used in the adsorption / desorption isotherm measurement is heated to 100°C in a nitrogen atmosphere. The water content may be determined specifically by a method described in the Examples.

[0035] The polyallylamine according to this embodiment can efficiently absorb carbon dioxide, for example, at 0 to 50° C. The carbon dioxide adsorbed in the polyallylamine can be desorbed by heating to, for example, 50 to 400° C. Such absorption and desorption of carbon dioxide can be repeated.

[0036] The polyallylamine according to this embodiment may be produced by reacting an unsubstituted polyallylamine with a compound represented by the following general formula (2): In general formula (2), n is a number from 1 to 5, A is a carboxy group or an acyl halide group (-C(=O)X, where X is a fluorine atom, chlorine atom, bromine atom, or iodine atom), and each R is independently a halogen atom or a hydroxyl group.

[0037] [ka]

[0038] An amide bond can be formed by reacting the amino group of the unsubstituted polyallylamine with the carboxy group or acyl halide group of the compound represented by general formula (2).

[0039] The unsubstituted polyallylamine is not particularly limited, and may be produced by a known method, or a commercially available product may be used.

[0040] The compound represented by general formula (2) is not particularly limited, and may be produced by a known method, or a commercially available product may be used.

[0041] The reaction between the unsubstituted polyallylamine and the compound represented by general formula (2) may be carried out in a solvent, and the solvent may be stirred during the reaction.

[0042] The solvent is not particularly limited as long as it can dissolve the unsubstituted polyallylamine and the compound represented by general formula (2) and has low reactivity with the compound represented by general formula (2). Examples of the solvent include water, N,N-dimethylformamide, N,N-dimethylacetamide, methanol, ethanol, acetone, dichloromethane, chloroform, and a mixture of two or more of these.

[0043] The content of the unsubstituted polyallylamine in the solvent may be, for example, 0.5 to 20% by mass, or 1 to 10% by mass.

[0044] The content of the compound represented by general formula (2) in the solvent may be, for example, 0.0001 to 10 chemical equivalents relative to the amino groups of the unsubstituted polyallylamine, or 0.005 to 4 chemical equivalents. When the chemical equivalent of the compound represented by general formula (2) relative to the amino groups of the unsubstituted polyallylamine is high, the ratio of the number of repeating units represented by general formula (1) to the total number of repeating units tends to be high.

[0045] However, if the chemical equivalent exceeds the threshold value, the ratio will not increase even if the chemical equivalent is further increased. The threshold value varies depending on the type of compound represented by general formula (2). For example, at 80 ° C, when the compound represented by general formula (2) is 4-fluorobenzoic acid, the threshold value is about 7; when the compound represented by general formula (2) is 4-hydroxybenzoic acid, the threshold value is about 7; when the compound represented by general formula (2) is 2,3,5,6-tetrafluorobenzoic acid, the threshold value is about 1; when the compound represented by general formula (2) is pentafluorobenzoic acid, the threshold value is about 0.7; and when the compound represented by general formula (2) is 2,3,5,6-tetrafluoro-4-hydroxybenzoic acid, the threshold value is usually about 0.9. The threshold value tends to be positively correlated with the pKa of the compound represented by general formula (2).

[0046] Other components may be added to the solvent as needed. When A is a carboxy group, examples of the other components include condensing agents such as 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMT-MM), dicyclohexylcarbodiimide (DCC), and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC). The content of the condensing agent in the solvent may be, for example, 0.05 to 5 chemical equivalents or 0.5 to 1.5 chemical equivalents relative to the compound represented by general formula (1). When A contains an acyl halide group, examples of the other components include a base such as triethylamine. The base can be used for the purpose of neutralizing the hydrogen halide by-product.

[0047] In the above reaction, when A is a carboxy group, the reaction temperature may be 75 to 95°C and the reaction time may be 10 to 25 hours. When A is an acyl halide group, the reaction temperature may be 0 to 25°C and the reaction time may be 30 minutes to 10 hours. When the reaction temperature is high, the ratio of the number of repeating units represented by general formula (1) to the total number of repeating units tends to increase. When the reaction time is long, the ratio of the number of repeating units represented by general formula (1) to the total number of repeating units tends to increase. [Example]

[0048] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In Tables 1 to 5, the "introduction rate" refers to the ratio of the number of repeating units represented by general formula (1) to the total number of repeating units.

[0049] Polyallylamine was synthesized by the method described in the synthesis example below. 1 H NMR spectra and infrared (IR) spectra were obtained by the following methods. The ratio of the number of repeating units represented by general formula (1) to the total number of repeating units was calculated by the following method.

[0050] ( 1 H NMR spectrum) 1 H NMR spectra were measured using a 400 JJYH spectrometer (400 MHz, JEOL). Dimethyl sulfoxide-d6 was used as the measurement solvent, and tetramethylsilane was used as the internal standard.

[0051] (Proportion of the number of repeating units represented by general formula (1) based on the total number of repeating units) The ratio of the number of repeating units represented by general formula (1) to the total number of repeating units is: 1The calculation was based on the H NMR spectrum. Specifically, the hydrogen atoms bonded to the carbon atoms (e.g., a, b, a', and b' in Figure 1) and the hydrogen atoms bonded to the nitrogen atoms (e.g., d and d' in Figure 1) derived from unsubstituted polyallylamine (PAA) were 1 The values were calculated from the peak areas of the HNMR spectrum using the above formula A.

[0052] (IR spectrum) IR spectra were measured by attenuated total reflection (ATR) using an FT / IR-6100 spectrometer (JASCO).

[0053] (Synthesis Example 1: Polyallylamine having a 4-fluorobenzamide skeleton) 4-Fluorobenzoic acid (FBA, Tokyo Chemical Industry Co., Ltd.) was dissolved in 10 mL of N,N-dimethylformamide (DMF, anhydrous, Kishida Chemical Co., Ltd.) at 1.85 chemical equivalents relative to the amino groups of the unsubstituted polyallylamine described below. To this solution, 1 chemical equivalent of 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMT-MM, Tokyo Chemical Industry Co., Ltd.) relative to the 4-fluorobenzoic acid and 5 mL of a 15% by weight aqueous solution of unsubstituted polyallylamine (weight average molecular weight 1600, Nittobo Medical Co., Ltd.) were added, and the mixture was stirred at 80 °C for 19 hours. Then, 200 mL of acetone (Fujifilm Wako Pure Chemical Industries, Ltd.) was added, and the precipitate was collected by membrane filtration. The precipitate was washed with acetone (Fujifilm Wako Pure Chemical Industries, Ltd.) and acetonitrile (Kanto Chemical Co., Ltd.) and dried overnight in a desiccator at 90°C to obtain 0.674 g of polyallylamine (PAA-FBA(1)) having a repeating unit represented by general formula (1) containing a 4-fluorobenzamide skeleton. The yield was 88.3% by mass.

[0054] Polyallylamine (PAA-FBA (2) to (7)) having a repeating unit represented by general formula (1) containing a 4-fluorobenzamide skeleton was obtained in the same manner as in the method for obtaining PAA-FBA (1), except that the reaction temperature, reaction time, and chemical equivalent of 4-fluorobenzoic acid (FBA, Tokyo Chemical Industry Co., Ltd.) shown in Table 1 were used instead of a reaction temperature of 80°C, a reaction time of 19 hours, and 1.85 chemical equivalents of 4-fluorobenzoic acid relative to the amino group of the unsubstituted polyallylamine.

[0055] PAA-FBA(1) 1 The H-NMR and IR spectra are shown in Figures 1 and 2, respectively. 1 The H-NMR chemical shifts and IR absorption peaks were as follows: 1 H-NMR (400 MHz, dimethyl sulfoxide-d6, δ (ppm)): 8.1 (s, 1H), 7.9 (d, 2H), 7.1 (d, 2H), 3.1-2.9 (br, 2H), 0.8-2.0 (br, 6H). IR (ATR, v (cm -1 )):3260,3060,2850,1680,1590,1570cm -1 .

[0056] [Table 1]

[0057] (Synthesis Example 2: Polyallylamine with a 4-hydroxybenzamide skeleton) Polyallylamine (PAA-HBA (1) to (7)) having a repeating unit represented by general formula (1) containing a 4-hydroxybenzamide skeleton was obtained in the same manner as for obtaining PAA-FBA (1), except that the reaction temperature was 80°C, the reaction time was 19 hours, and 1.85 chemical equivalents of 4-fluorobenzoic acid relative to the amino groups of the unsubstituted polyallylamine were replaced by 4-hydroxybenzoic acid (HBA, Tokyo Chemical Industry Co., Ltd.) in the amounts shown in Table 2. 0.646 g of PAA-HBA (1) was obtained, for a yield of 84.6% by mass.

[0058] PAA-HBA(1) 1 The H-NMR and IR spectra are shown in Figures 3 and 4, respectively. 1 The H-NMR chemical shifts and IR absorption peaks were as follows: 1 H-NMR (400 MHz, dimethyl sulfoxide-d6, δ (ppm)): 8.0 (s, 1H), 7.8 (d, 2H), 6.8 (d, 2H), 3.1-2.9 (br, 2H), 0.8-2.0 (br, 6H). IR (ATR, v (cm -1 )):3260,3060,2850,1680,1590,1570cm -1 .

[0059] [Table 2]

[0060] (Synthesis Example 3: Polyallylamine having a 2,3,5,6-tetrafluoro-4-hydroxybenzamide skeleton) Polyallylamine (PAA-TFHBA (1)-(5)) having a repeating unit represented by general formula (1) containing a 2,3,5,6-tetrafluoro-4-hydroxybenzamide skeleton was obtained in the same manner as for obtaining PAA-FBA (1), except that the reaction temperature was 80°C, the reaction time was 19 hours, and 1.85 chemical equivalents of 4-fluorobenzoic acid relative to the amino groups of the unsubstituted polyallylamine were replaced with 2,3,5,6-tetrafluoro-4-hydroxybenzoic acid (TFHBA, Tokyo Chemical Industry Co., Ltd.) in the amounts shown in Table 3. 0.655 g of PAA-TFHBA (1) was obtained, for a yield of 85.1% by mass.

[0061] PAA-TFHBA(1) 1 The H-NMR and IR spectra are shown in Figures 5 and 6, respectively. 1 The H-NMR chemical shifts and IR absorption peaks were as follows: 1 H-NMR (400 MHz, dimethyl sulfoxide-d6, δ (ppm)): 8.1 (s, 1H), 3.9-2.9 (br, 2H), 0.8-2.0 (br, 6H). IR (ATR, v (cm -1 )):3260,3060,2850,1680,1590,1570cm -1 .

[0062] [Table 3]

[0063] (Synthesis Example 4: Polyallylamine having a 2,3,5,6-tetrafluorobenzamide skeleton) Polyallylamine (PAA-TFBA(1)-(13)) having a repeating unit represented by general formula (1) containing a 2,3,5,6-tetrafluorobenzamide skeleton was obtained in the same manner as for obtaining PAA-FBA(1), except that the reaction temperature was 80°C, the reaction time was 19 hours, and 1.85 chemical equivalents of 4-fluorobenzoic acid relative to the amino groups of the unsubstituted polyallylamine were replaced with 2,3,5,6-tetrafluorobenzoic acid (TFBA, Tokyo Chemical Industry Co., Ltd.) in the amounts shown in Table 4. 0.506 g of PAA-TFBA(1) was obtained, for a yield of 65.8% by mass.

[0064] PAA-TFBA(1) 1 The H-NMR and IR spectra are shown in Figures 7 and 8, respectively. 1 The H-NMR chemical shifts and IR absorption peaks were as follows: 1 H-NMR (400 MHz, dimethyl sulfoxide-d6, δ (ppm)): 8.1 (s, 1H), 3.9-2.9 (br, 2H), 0.8-2.0 (br, 6H). IR (ATR, v (cm -1 )):3260,3060,2850,1680,1590,1570cm -1 .

[0065] [Table 4]

[0066] (Synthesis Example 5: Polyallylamine having a pentafluorobenzamide skeleton) Polyallylamine (PAA-PFBA (1) to (9)) having a repeating unit represented by general formula (1) containing a pentafluorobenzamide skeleton was obtained in the same manner as for obtaining PAA-FBA (1), except that the reaction temperature was 80 ° C, the reaction time was 19 hours, and 1.85 chemical equivalents of 4-fluorobenzoic acid relative to the amino group of the unsubstituted polyallylamine were replaced with pentafluorobenzoic acid (PFBA, Tokyo Chemical Industry Co., Ltd.) in the reaction temperature, reaction time, and chemical equivalents relative to the amino group of the unsubstituted polyallylamine shown in Table 5. 0.505 g of PAA-PFBA (1) was obtained, with a yield of 65.6% by mass.

[0067] PAA-PFBA(1) 1 The H-NMR and IR spectra are shown in Figures 9 and 10, respectively. 1 The H-NMR chemical shifts and IR absorption peaks were as follows: 1 H-NMR (400 MHz, dimethyl sulfoxide-d6, δ (ppm)): 8.1 (s, 1H), 3.9-2.9 (br, 2H), 0.8-2.0 (br, 6H). IR (ATR, v (cm -1 )):3260,3060,2850,1680,1590,1570cm -1 .

[0068] [Table 5]

[0069] (Relationship between the chemical equivalent of FBA, HBA, TFHBA, TFBA, and PFBA and the ratio of the number of repeating units represented by general formula (1) based on the total number of repeating units) Figures 11(a) to 11(e) show the relationship between the chemical equivalents of FBA, HBA, TFHBA, TFBA, and PFBA relative to the amino groups of unsubstituted polyallylamine when the reaction temperature was 80°C in Synthesis Examples 1 to 5, and the ratio of the number of repeating units having a 4-fluorobenzamide skeleton, a 4-hydroxybenzamide skeleton, a 2,3,5,6-tetrafluoro-4-hydroxybenzamide skeleton, a 2,3,5,6-tetrafluorobenzamide skeleton, and a pentafluorobenzamide skeleton relative to the total number of repeating units. As shown in Figures 11(a) to 11(e), once the chemical equivalents exceeded a threshold value, the ratios hardly changed even if the chemical equivalents were increased further. Note that the threshold value was defined as the minimum chemical equivalent within the range of chemical equivalents relative to PAA at which the incorporation rate remained constant. Table 6 shows the threshold value and the pKa values of FBA, HBA, TFHBA, TFBA, and PFBA. As shown in Table 6 below, the saturated chemical equivalent was correlated with the pKa of the compound represented by general formula (1).

[0070] [Table 6]

[0071] (Evaluation of carbon dioxide adsorption / desorption isotherms) The carbon dioxide adsorption and desorption isotherms of the synthesized PAA-FBA (1), PAA-HBA (1), PAA-TFHBA (1), PAA-TFBA (1), and PAA-PFBA (1) as well as unsubstituted polyallylamine were determined using a BELSORP-max II (MicrotracBEL). More specifically, each of the polyallylamines was dried under reduced pressure at 100°C for 1.7 hours before being subjected to the BELSORP-max II. The adsorption isotherms were obtained at 25°C. Figure 12 shows the adsorption and desorption isotherms of polyallylamine, where (a) is the adsorption and desorption isotherm of PAA-FBA (1), (b) is the adsorption and desorption isotherm of PAA-HBA (1), (c) is the adsorption and desorption isotherm of PAA-TFBA (1), (d) is the adsorption and desorption isotherm of PAA-PFBA (1), (e) is the adsorption and desorption isotherm of PAA-TFHBA (1), and (f) is the adsorption and desorption isotherm of unsubstituted polyallylamine. In Figure 12, "PAA" means unsubstituted polyallylamine.

[0072] As shown in Figures 12(a) to (e), PAA-FBA(1), PAA-HBA(1), PAA-TFHBA(1), PAA-TFBA(1), and PAA-PFBA(1) were all capable of adsorbing and desorbing carbon dioxide.

[0073] (Evaluation of carbon dioxide absorption capacity) The carbon dioxide absorption capacities of the synthesized PAA-FBA (1), PAA-HBA (1), PAA-TFHBA (1), PAA-TFBA (1), and PAA-PFBA (1) and unsubstituted polyallylamine were determined by subtracting the amount of water contained in each polyallylamine from the amount of carbon dioxide absorbed when the equilibrium pressure of carbon dioxide was equal to the saturated vapor pressure in the "Evaluation of Carbon Dioxide Adsorption and Desorption Isotherms" section above. The water content was measured by subjecting each polyallylamine used in the evaluation of the adsorption and desorption isotherms to thermogravimetric analysis using a TG8120 (Rigaku Corporation). In this thermogravimetric analysis, the temperature was raised from 25°C at 4°C / min under a nitrogen atmosphere, and the amount of mass loss of each polyallylamine was measured until it reached 400°C, which was then used as the water content. The carbon dioxide absorption capacities of PAA-FBA(1), PAA-HBA(1), PAA-TFHBA(1), PAA-TFBA(1), and PAA-PFBA(1) and unsubstituted polyallylamine are shown in Figure 13. In Figure 13, "PAA (0%)" means unsubstituted polyallylamine.

[0074] As shown in Figure 13, the carbon dioxide absorption capacities of the polyallylamine compounds were, in descending order, PAA-PFBA(1), PAA-TFBA(1), PAA-TFHBA(1), PAA-FBA(1), and PAA-HBA(1). The carbon dioxide absorption capacities of these polyallylamine compounds were 17 times, 14 times, 10 times, 9 times, and more than 9 times higher than that of unsubstituted polyallylamine, respectively, demonstrating that they were sufficiently large.

Claims

1. A polyallylamine having a repeating unit represented by the following general formula (1): 【Chemical 1】 [In the formula, n is a number from 1 to 5, and each R independently represents a halogen atom or a hydroxyl group.]

2. The polyallylamine according to claim 1 , wherein the halogen atom is a fluorine atom.

3. The polyallylamine according to claim 1, wherein the repeating unit represented by general formula (1) has a skeleton selected from the group consisting of a 4-fluorobenzamide skeleton, a 4-hydroxybenzamide skeleton, a 2,3,5,6-tetrafluorobenzamide skeleton, a pentafluorobenzamide skeleton, and a 2,3,5,6-tetrafluoro-4-hydroxybenzamide skeleton.

4. The polyallylamine according to any one of claims 1 to 3, wherein the number of repeating units represented by formula (1) is 10 to 95% based on the total number of repeating units.

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