A polybenzimidazole containing a toluidine structure, and a preparation method and application thereof

Abstract

This application discloses a polybenzimidazole containing a telrogal base structure, its preparation method, and its application. The process includes the following steps: (1) mixing 4-nitro-o-phenylenediamine, p-toluenesulfonyl chloride, and solvent I, reacting to obtain 1,2-dimethylbenzenesulfonamide-4-nitrobenzene; (2) mixing 1,2-dimethylbenzenesulfonamide-4-nitrobenzene with hydrazine hydrate, palladium on carbon catalyst, and solvent II, reacting to obtain intermediate A; (3) mixing intermediate A with dimethylformaldehyde and solvent III, reacting to obtain intermediate B; (4) mixing intermediate B with solvent IV, reacting to obtain a tetraamine monomer containing a telrogal base structure; (5) mixing the tetraamine monomer containing a telrogal base structure with a diacid monomer and solvent V, reacting to obtain the polybenzimidazole containing the telrogal base structure.

Description

Technical Field

[0001] This application relates to a polybenzimidazole containing a telrog base structure, its preparation method and application, belonging to the field of gas separation membranes. Background Technology

[0002] Polymer-based separation membranes possess significant industrial application potential in the field of gas separation due to their advantages such as ease of processing, diverse structures and types, and low cost. Over the past few decades, polymer separation membranes have achieved good results in several gas separation systems, including hydrogen recovery, natural gas purification, nitrogen-enriched air preparation, and carbon dioxide separation and capture. An ideal gas separation membrane should simultaneously possess high gas permeability and separation selectivity. However, for each pair of gases to be separated, there is a contradictory relationship between the permeability and selectivity of polymer gas separation membranes (the trade-off phenomenon). High-permeability polymer membranes often have low separation selectivity, while high-selectivity polymer membranes often have low permeability. The gas separation performance of most polymer membranes lies below the Robeson upper limit. Therefore, enabling gas separation membranes to exceed the Robeson upper limit is a research goal in the design and synthesis of polymer membrane materials.

[0003] Polybenzimidazole (PBM) is an important gas separation membrane material with excellent thermal stability, chemical stability, mechanical properties, and processability. However, due to the strong hydrogen bonding between its molecular chains, PBM molecules are highly compact, resulting in low gas permeation rates in these membranes. Through structural design and control of polymer membrane materials, microporous polymers (PIMs) with ultra-high gas permeability have emerged in recent years. These materials have loosely packed molecular chains, forming micropores between the chains that facilitate rapid gas molecule transport. To improve the gas permeation rate of separation membranes, the structural design concept of PIM materials has been applied to the structural design and synthesis of various polymers. Monomers containing structures such as spirobisindenne, tripterene, and spirobisfluorene have been designed and used in the synthesis of polymer gas separation membranes. The synthesis of these materials significantly improves the gas permeability of polymer separation membranes. Summary of the Invention

[0004] This invention uses 4-nitro-o-phenylenediamine as a raw material, and through a series of reactions including sulfonation, reduction, condensation, and hydrolysis, a tetraamine monomer containing a telrogallic base structure is obtained. This tetraamine monomer is then subjected to a high-temperature polymerization reaction with a diacid monomer to produce a polybenzimidazole containing a telrogallic base structure. The polybenzimidazole is dissolved in an organic solvent to prepare a casting solution, which is then coated onto a glass plate. The solvent is dried by heat treatment to obtain a gas separation membrane.

[0005] According to one aspect of this application, a method for preparing polybenzimidazole containing a telrogal base structure is provided, comprising the following steps:

[0006] (1) Mix 4-nitro-o-phenylenediamine, p-toluenesulfonyl chloride and solvent I to react I to obtain 1,2-dibenzenesulfonamide-4-nitrobenzene;

[0007] (2) 1,2-dibenzenesulfonamide-4-nitrobenzene was mixed with hydrazine hydrate, palladium on carbon catalyst and solvent II, and reaction II was carried out to obtain intermediate A;

[0008] (3) Intermediate A is mixed with dimethyl formaldehyde and solvent III, and reaction III is carried out to obtain intermediate B;

[0009] (4) Intermediate B is mixed with solvent IV and reacted with IV to obtain a tetraamine monomer containing a Teleg base structure, 2,3,8,9-tetraamino-6H,12H-5,11-methylenediphenyl[b,f][1,5]-diaza-heterocyclic ring.

[0010] (5) Mix the tetraamine monomer containing the telrog base structure with the diacid monomer and solvent V, react V, and obtain the polybenzimidazole containing the telrog base structure;

[0011] The repeating unit of the polybenzimidazole containing the telreg base structure has the structure shown in Formula I:

[0012]

[0013] Where n is the degree of aggregation, and n is an integer between 1 and 500.

[0014] Solvent I is selected from at least one of pyridine, triethylamine, 2-methylpyridine, 3-methylpyridine, 2-ethylpyridine, or 3-ethylpyridine;

[0015] The temperature of reaction I is 10–100°C;

[0016] The reaction time for reaction I is 3–30 h;

[0017] The molar ratio of 4-nitro-o-phenylenediamine to p-toluenesulfonyl chloride is 1:1 to 1:20;

[0018] The total mass ratio of the 4-nitro-o-phenylenediamine and p-toluenesulfonyl chloride to solvent I is 1:1 to 1:20.

[0019] Solvent II is selected from at least one of methanol, ethanol, tetrahydrofuran, dichloromethane, trichloromethane, or toluene;

[0020] The temperature of reaction II is 30–100°C;

[0021] The reaction time for reaction II is 2–20 h;

[0022] The molar ratio of 1,2-dibenzenesulfonamide-4-nitrobenzene to hydrazine hydrate is 1:2 to 1:20;

[0023] The mass ratio of the palladium catalyst on carbon to 1,2-dibenzenesulfonamide-4-nitrobenzene is 1:1 to 1:30;

[0024] The total mass ratio of the 1,2-dibenzenesulfonamide-4-nitrobenzene, palladium on carbon catalyst, and hydrazine hydrate to solvent II is 1:1 to 1:20.

[0025] Solvent III is selected from trifluoroacetic acid;

[0026] The temperature of reaction III is -20 to 0°C;

[0027] The reaction time for reaction III is 2–20 h;

[0028] The molar ratio of intermediate A to dimethyl formaldehyde is 1:1 to 1:20;

[0029] The total mass ratio of intermediate A and dimethylformaldehyde to solvent III is 1:2 to 1:20.

[0030] The solvent IV is selected from at least one of concentrated sulfuric acid, concentrated nitric acid, concentrated hydrochloric acid, methanesulfonic acid, or trifluoromethanesulfonic acid;

[0031] The temperature of reaction IV is 25–100°C;

[0032] The reaction IV time is 2–20 h;

[0033] The mass ratio of intermediate B to solvent IV is 1:2 to 1:30.

[0034] The diacid monomer is selected from at least one of isophthalic acid, terephthalic acid, 4,4'-dicarboxylic acid diphenyl sulfone, 1,4-naphthalenedicarboxylic acid, 4,4'-dicarboxylic acid biphenyl, 2,2-bis(4-carboxyphenyl)hexafluoropropane or 4,4'-dicarboxylic acid diphenyl ether;

[0035] The solvent V is selected from polyphosphoric acid;

[0036] The temperature of reaction V is 150–250°C;

[0037] The reaction time V is 5–50 h;

[0038] The total mass ratio of the tetraamine monomer and diacid monomer containing the telrog base structure to the solvent V is 1:5 to 1:100.

[0039] According to another aspect of this application, a polybenzimidazole containing a telrogal base structure prepared by the above-described preparation method is provided.

[0040] According to another aspect of this application, a gas separation membrane is provided, wherein the above-mentioned polybenzimidazole containing the telrogal base structure is dissolved in an organic solvent to prepare a casting solution, the casting solution is coated on a glass plate, and the organic solvent is dried by a heat treatment process to obtain the gas separation membrane.

[0041] The organic solvent is selected from at least one of N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide, m-cresol, and p-chlorophenol;

[0042] The mass ratio of the polybenzimidazole containing the telrogal base structure to the organic solvent is 1:5 to 1:100.

[0043] The heat treatment includes: treatment at 50–80°C for 2–30 hours under normal pressure, followed by treatment at 100–250°C for 1–20 hours under a pressure ≤0.02MPa.

[0044] The beneficial effects that this application can produce include:

[0045] This invention relates to a method for preparing polybenzimidazole containing a telrogalgesic base structure and its application in gas separation membranes. The polybenzimidazole containing a telrogalgesic base structure is prepared from 4-nitro-o-phenylenediamine as a raw material through a series of reactions including sulfonation, reduction, condensation, and hydrolysis to obtain a tetraamine monomer containing a telrogalgesic base structure. This tetraamine monomer is then subjected to a high-temperature polymerization reaction with a diacid monomer to obtain polybenzimidazole containing a telrogalgesic base structure. The polybenzimidazole is dissolved in an organic solvent to prepare a casting solution, which is then coated onto a glass plate. The solvent is dried by heat treatment to obtain the polybenzimidazole gas separation membrane containing a telrogalgesic base structure. According to Freeman's theory [ACS Macro Letters, 2014, 3:597-601], in order to simultaneously achieve high gas permeability and separation selectivity, increasing the rigidity of the polymer chains, in addition to introducing micropores between the molecular chains, also plays an important role. Studies have shown [Macromolecules, 2016, 49: 4147-4154] that polymeric membrane materials containing telreg base structures exhibit good gas permeation and separation performance, which is attributed to the inherent rigid and twisted amine structure of the telreg base. Therefore, the gas permeation and separation performance of polybenzimidazole can be improved by introducing telreg base structures into the polymer chain. Detailed Implementation

[0046] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0047] Unless otherwise specified, the raw materials and catalysts used in the embodiments of this application were all purchased commercially.

[0048] The permeation and separation performance of the membranes prepared in the embodiments of the present invention are characterized by the permeation coefficient P and separation coefficient α of pure gas.

[0049] Using a gas permeation apparatus, the gas permeation performance of the membrane is tested using the "constant volume method." When gas transfer reaches a steady state, the gas permeability coefficient is calculated using the following formula:

[0050]

[0051] Where P is the gas permeability coefficient (unit: Barrer, 1 Barrer = 10⁻⁶). -10 cm 3 (STP).cm / cm 2 .s.cmHg), V m It is the molar volume of a gas under standard conditions (unit: cm³). 3 (STP) / mol), V is the volume of the osmotic side vessel (unit: cm³). 3 L is the membrane thickness (in cm), and A is the effective membrane area (in cm²). 2 R is the universal gas constant (value is 6236.56 cm⁻¹). 3 .cmHg / mol.K), T is the temperature under the test conditions (in K), p0 is the osmotic pressure difference (in cmHg), and dp / dt is the gas permeation rate (in cmHg / s).

[0052] The ideal separation coefficient α between gases A and B is the ratio of their permeability coefficients.

[0053]

[0054] The present invention will be described in detail below with reference to the embodiments.

[0055] Example 1

[0056] The preparation method of polybenzimidazole containing a telrogal base structure disclosed in this embodiment and its application in a gas separation membrane are prepared by the following steps:

[0057] (1) 15.31 g of 4-nitro-o-phenylenediamine (100 mmol) and 28.60 g of p-toluenesulfonyl chloride (150 mmol) were added to 300 g of pyridine. After mixing thoroughly, the reaction flask was placed in a 50 °C water bath and reacted for 5 h. The reaction was stopped, and the reaction solution was poured into water to precipitate the product. After filtration and drying, 35.15 g of product (76 mmol) was obtained. All of the above product was added to 200 g of ethanol, and 3.50 g of palladium on carbon was added. The reaction flask was placed in an 80 °C water bath, and 47.40 g of 80% hydrazine hydrate (758 mmol) was added dropwise. The reaction was continued for 8 h. After filtration, the reaction solution was evaporated to dryness, the product was washed with water and dried to obtain 2 8.86 g of product (67 mmol); 24.99 g (58 mmol) of the above product was added to 225 g of trifluoroacetic acid, cooled to 0 °C using an ice-water bath, and 8.81 g of dimethylformaldehyde (116 mmol) was added dropwise. The reaction was continued at 0 °C for 8 h. The reaction solution was poured into water to precipitate, filtered, and dried to obtain 24.20 g of product (27 mmol); all of the above product was added to 100 g of concentrated sulfuric acid, and the reaction flask was placed in a 50 °C water bath to react for 3 h. The reaction solution was poured into ice water to precipitate, filtered, washed, and dried to obtain 5.65 g of product TBTA (20 mmol).

[0058] (2) 2.82 g TBTA (10 mmol) and 1.66 g isophthalic acid (10 mmol) were added to 90 g polyphosphoric acid and reacted in an oil bath at 190 °C for 20 h. The reaction solution was poured into water to precipitate the product, which was then placed in a saturated sodium bicarbonate aqueous solution, washed with water until neutral, and dried to obtain 3.38 g of product. The weight-average molecular weight of this polybenzimidazole was 56010, the number-average molecular weight was 30910, and the polydispersity index was 1.812.

[0059] (3) Dissolve 1.0g of the above polybenzimidazole in 10g of N,N-dimethylacetamide to prepare a casting solution. Coat the casting solution onto a glass plate, treat it at 60°C under normal pressure for 20h, and then heat treat it at 200°C and 0.01MPa for 10h to dry the solvent, thus obtaining a gas separation membrane.

[0060] The gas permeation performance of the above polybenzimidazole membrane was tested at 25℃ and 0.2MPa. The test results were: P(H2)=18.3Barrer, P(N2)=0.26Barrer, P(CO2)=4.76Barrer, gas separation coefficients α(H2 / N2)=70.38, α(CO2 / N2)=18.31.

[0061] Example 2

[0062] The preparation method of polybenzimidazole containing a telrogal base structure disclosed in this embodiment and its application in a gas separation membrane are prepared by the following steps:

[0063] (1) 15.31 g of 4-nitro-o-phenylenediamine (100 mmol) and 33.36 g of p-toluenesulfonyl chloride (175 mmol) were added to 300 g of pyridine. After mixing thoroughly, the reaction flask was placed in a 50 °C water bath and reacted for 5 h. The reaction was then stopped, and the reaction solution was poured into water to precipitate the product. After filtration and drying, 36.92 g of product (80 mmol) was obtained. All of the above product was added to 250 g of ethanol, and 3.80 g of palladium on carbon was added. The reaction flask was placed in an 80 °C water bath, and 50.63 g of 80% hydrazine hydrate (810 mmol) was added dropwise. The reaction was continued for 8 h. After filtration, the reaction solution was evaporated to dryness, the product was washed with water, and then dried to obtain 31.0 g of product. 7 g of product (72 mmol); 24.99 g (58 mmol) of the above product was added to 225 g of trifluoroacetic acid, cooled to -5 °C using an ice-salt bath, and 10.27 g of dimethylformaldehyde (135 mmol) was added dropwise. The reaction was continued at -5 °C for 6 h. The reaction solution was poured into water to precipitate, filtered, and dried to obtain 25.17 g of product (28 mmol); all of the above product was added to 110 g of concentrated sulfuric acid, and the reaction flask was placed in a 50 °C water bath to react for 3.5 h. The reaction solution was poured into ice water to precipitate, filtered, washed, and dried to obtain 6.21 g of product TBTA (22 mmol).

[0064] (2) 2.82 g TBTA (10 mmol) and 1.66 g terephthalic acid (10 mmol) were added to 100 g polyphosphoric acid and reacted in an oil bath at 200 °C for 25 h. The reaction solution was poured into water to precipitate the product, which was then placed in a saturated sodium bicarbonate aqueous solution, washed with water until neutral, and dried to obtain 3.31 g of product. The weight-average molecular weight of this polybenzimidazole was 69647, the number-average molecular weight was 35680, and the polydispersity index was 1.952.

[0065] (3) Dissolve 1.0g of the above polybenzimidazole in 10g of N,N-dimethylformamide to prepare a casting solution. Coat the casting solution onto a glass plate, treat it at 55°C under normal pressure for 20h, and then heat treat it at 180°C and 0.005MPa for 10h to dry the solvent, thus obtaining a gas separation membrane.

[0066] The gas permeation performance of the above polybenzimidazole membrane was tested at 25℃ and 0.2MPa. The test results were: P(H2)=15.7Barrer, P(N2)=0.21Barrer, P(CO2)=4.17Barrer, gas separation coefficients α(H2 / N2)=74.76, α(CO2 / N2)=19.86.

[0067] Example 3

[0068] The preparation method of polybenzimidazole containing a telrogal base structure disclosed in this embodiment and its application in a gas separation membrane are prepared by the following steps:

[0069] (1) 15.31 g of 4-nitro-o-phenylenediamine (100 mmol) and 28.60 g of p-toluenesulfonyl chloride (150 mmol) were added to 300 g of triethylamine. After mixing thoroughly, the reaction flask was placed in a 50 °C water bath for 5 h. The reaction was stopped, and the reaction solution was poured into water to precipitate the product. After filtration and drying, 36.01 g of product (78 mmol) was obtained. All of the above product was added to 200 g of ethanol, and 3.60 g of palladium on carbon was added. The reaction flask was placed in an 80 °C water bath, and 48.75 g of 80% hydrazine hydrate (780 mmol) was added dropwise. The reaction was continued for 8 h. After filtration, the reaction solution was evaporated to dryness, the product was washed with water and dried to obtain 2 9.78 g of product (69 mmol); 24.99 g (58 mmol) of the above product was added to 250 g of trifluoroacetic acid, cooled to 0 °C using an ice-water bath, and 9.51 g of dimethylformaldehyde (125 mmol) was added dropwise. The reaction was continued at 0 °C for 8 h. The reaction solution was poured into water to precipitate, filtered, and dried to obtain 24.20 g of product (27 mmol); all of the above product was added to 100 g of concentrated sulfuric acid, and the reaction flask was placed in a 60 °C water bath to react for 2 h. The reaction solution was poured into ice water to precipitate, filtered, washed, and dried to obtain 5.93 g of product TBTA (21 mmol).

[0070] (2) 2.82 g TBTA (10 mmol) and 3.06 g 4,4'-dicarboxylic acid diphenyl sulfone (10 mmol) were added to 110 g polyphosphoric acid and reacted in an oil bath at 180 °C for 20 h. The reaction solution was poured into water to precipitate, and the product was then placed in a saturated sodium bicarbonate aqueous solution, washed with water until neutral, and dried to obtain 4.65 g of product. The weight-average molecular weight of this polybenzimidazole was 79595, the number-average molecular weight was 41760, and the polydispersity index was 1.906.

[0071] (3) Dissolve 1.0g of the above polybenzimidazole in 10g of N-methylpyrrolidone to prepare a casting solution. Coat the casting solution onto a glass plate and treat it at 70°C under normal pressure for 20h. Then heat treat it at 230°C and 0.005MPa for 15h to dry the solvent and obtain a gas separation membrane.

[0072] The gas permeation performance of the above polybenzimidazole membrane was tested at 25℃ and 0.2MPa. The test results were: P(H2)=23.3Barrer, P(N2)=0.32Barrer, P(CO2)=5.81Barrer, gas separation coefficient α(H2 / N2)=72.81, α(CO2 / N2)=18.12.

[0073] Example 4

[0074] The preparation method of polybenzimidazole containing a telrogal base structure disclosed in this embodiment and its application in a gas separation membrane are prepared by the following steps:

[0075] (1) 15.31 g of 4-nitro-o-phenylenediamine (100 mmol) and 33.36 g of p-toluenesulfonyl chloride (175 mmol) were added to 300 g of triethylamine. After mixing thoroughly, the reaction flask was placed in a 60°C water bath and reacted for 4 h. The reaction was stopped, and the reaction solution was poured into water to precipitate the product. After filtration and drying, 37.38 g of product (81 mmol) was obtained. All of the above product was added to 200 g of ethanol, and 4.50 g of palladium on carbon was added. The reaction flask was placed in an 80°C water bath, and 51.56 g of 80% hydrazine hydrate (825 mmol) was added dropwise. The reaction was continued for 6 h. After filtration, the reaction solution was evaporated to dryness, the product was washed with water and dried to obtain 30 g of triethylamine. 0.64 g of product (71 mmol); Take 24.99 g (58 mmol) of the above product and add it to 250 g of trifluoroacetic acid. Cool to 0 °C using an ice-water bath. Add 9.13 g of dimethylformaldehyde (120 mmol) dropwise and continue to react at 0 °C for 8 h. Pour the reaction solution into water to precipitate, filter and dry to obtain 24.20 g of product (27 mmol); Take all of the above product and add it to 100 g of concentrated hydrochloric acid. Place the reaction flask in a 60 °C water bath and react for 2.5 h. Pour the reaction solution into ice water to precipitate, filter, wash and dry to obtain 5.65 g of product TBTA (20 mmol).

[0076] (2) 2.82 g TBTA (10 mmol) and 2.58 g 4,4'-dicarboxylic acid diphenyl ether (10 mmol) were added to 100 g polyphosphoric acid and reacted in an oil bath at 190 °C for 25 h. The reaction solution was poured into water to precipitate, and the product was then placed in a saturated sodium bicarbonate aqueous solution, washed with water until neutral, and dried to obtain 4.19 g of product. The weight-average molecular weight of this polybenzimidazole was 88035, the number-average molecular weight was 45685, and the polydispersity index was 1.927.

[0077] (3) Dissolve 1.0g of the above polybenzimidazole in 10g of N,N-dimethylformamide to prepare a casting solution. Coat the casting solution onto a glass plate, treat it at 60°C under normal pressure for 15h, and then heat treat it at 190°C and 0.01MPa for 12h to dry the solvent to obtain a gas separation membrane.

[0078] The gas permeation performance of the above polybenzimidazole membrane was tested at 25℃ and 0.2MPa. The test results were: P(H2)=14.3Barrer, P(N2)=0.21Barrer, P(CO2)=3.99Barrer, gas separation coefficient α(H2 / N2)=68.10, α(CO2 / N2)=19.00.

[0079] Example 5

[0080] The preparation method of polybenzimidazole containing a telrogal base structure disclosed in this embodiment and its application in a gas separation membrane are prepared by the following steps:

[0081] (1) 15.31 g of 4-nitro-o-phenylenediamine (100 mmol) and 28.60 g of p-toluenesulfonyl chloride (150 mmol) were added to 300 g of 2-methylpyridine. After mixing thoroughly, the reaction flask was placed in a 55°C water bath for 7 h. The reaction was stopped, and the reaction solution was poured into water to precipitate the product. After filtration and drying, 37.84 g of product (82 mmol) was obtained. All of the above product was added to 200 g of ethanol, and 3.80 g of palladium on carbon was added. The reaction flask was placed in an 80°C water bath, and 51.88 g of 80% hydrazine hydrate (830 mmol) was added dropwise. The reaction was continued for 8 h. After filtration, the reaction solution was evaporated to dryness, the product was washed with water, and then dried to obtain the product. 30.21 g of product (70 mmol); 24.99 g (58 mmol) of the above product was added to 225 g of trifluoroacetic acid, cooled to -5 °C using an ice-salt bath, and 8.81 g of dimethylformaldehyde (116 mmol) was added dropwise. The reaction was continued at -5 °C for 6 h. The reaction solution was poured into water to precipitate, filtered, and dried to obtain 25.17 g of product (28 mmol); all of the above product was added to 100 g of concentrated hydrochloric acid, and the reaction flask was placed in a 50 °C water bath to react for 5 h. The reaction solution was poured into ice water to precipitate, filtered, washed, and dried to obtain 5.93 g of product TBTA (21 mmol).

[0082] (2) 2.82 g TBTA (10 mmol) and 2.16 g 1,4-naphthalenedicarboxylic acid (10 mmol) were added to 100 g polyphosphoric acid and reacted in an oil bath at 200 °C for 20 h. The reaction solution was poured into water to precipitate the product, which was then placed in a saturated sodium bicarbonate aqueous solution, washed with water until neutral, and dried to obtain 3.88 g of product. The weight-average molecular weight of this polybenzimidazole was 62305, the number-average molecular weight was 32570, and the polydispersity index was 1.913.

[0083] (3) Dissolve 1.0g of the above polybenzimidazole in 10g of dimethyl sulfoxide to prepare a casting solution. Coat the casting solution onto a glass plate, treat it at 80°C under normal pressure for 20h, and then heat treat it at 250°C and 0.01MPa for 20h to dry the solvent, thus obtaining a gas separation membrane.

[0084] The gas permeation performance of the above polybenzimidazole membrane was tested at 25℃ and 0.2MPa. The test results were: P(H2)=22.9Barrer, P(N2)=0.32Barrer, P(CO2)=6.19Barrer, gas separation coefficient α(H2 / N2)=71.56, α(CO2 / N2)=19.30.

[0085] Example 6

[0086] The preparation method of polybenzimidazole containing a telrogal base structure disclosed in this embodiment and its application in a gas separation membrane are prepared by the following steps:

[0087] (1) 15.31 g of 4-nitro-o-phenylenediamine (100 mmol) and 28.60 g of p-toluenesulfonyl chloride (150 mmol) were added to 300 g of 3-methylpyridine. After mixing thoroughly, the reaction flask was placed in a 60°C water bath for 5 h. The reaction was stopped, and the reaction solution was poured into water to precipitate the product. After filtration and drying, 37.84 g of product (82 mmol) was obtained. All of the above product was added to 200 g of ethanol, and 3.90 g of palladium on carbon was added. The reaction flask was placed in an 85°C water bath, and 51.88 g of 80% hydrazine hydrate (830 mmol) was added dropwise. The reaction was continued for 7 h. After filtration, the reaction solution was evaporated to dryness, the product was washed with water, and then dried to obtain the final product. 28.86 g of product (67 mmol) was obtained; 24.99 g (58 mmol) of the above product was added to 230 g of trifluoroacetic acid, cooled to 0 °C using an ice-water bath, and 9.13 g of dimethylformaldehyde (120 mmol) was added dropwise. The reaction was continued at 0 °C for 8 h. The reaction solution was poured into water to precipitate, filtered, and dried to obtain 25.17 g of product (28 mmol); all of the above product was added to 100 g of concentrated sulfuric acid, and the reaction flask was placed in a 55 °C water bath to react for 3 h. The reaction solution was poured into ice water to precipitate, filtered, washed, and dried to obtain 5.93 g of product TBTA (21 mmol).

[0088] (2) 2.82 g TBTA (10 mmol) and 3.92 g 2,2-bis(4-carboxyphenyl)hexafluoropropane (10 mmol) were added to 150 g polyphosphoric acid and reacted in an oil bath at 200 °C for 20 h. The reaction solution was poured into water to precipitate the product, which was then placed in a saturated sodium bicarbonate aqueous solution, washed with water until neutral, and dried to obtain 5.35 g of product. The weight-average molecular weight of this polybenzimidazole was 79365, the number-average molecular weight was 39270, and the polydispersity index was 2.021.

[0089] (3) Dissolve 1.0g of the above polybenzimidazole in 10g of N,N-dimethylacetamide to prepare a casting solution. Coat the casting solution onto a glass plate, treat it at 65°C under normal pressure for 20h, and then heat treat it at 200°C and 0.01MPa for 10h to dry the solvent, thus obtaining a gas separation membrane.

[0090] The gas permeation performance of the above polybenzimidazole membrane was tested at 25℃ and 0.2MPa. The test results were: P(H2)=39.3Barrer, P(N2)=0.66Barrer, P(CO2)=8.96Barrer, gas separation coefficient α(H2 / N2)=59.55, α(CO2 / N2)=13.58.

[0091] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A method for preparing polybenzimidazole containing a telrogal base structure, characterized in that, Includes the following steps: (1) Mix 4-nitro-o-phenylenediamine, p-toluenesulfonyl chloride and solvent I to react I to obtain 1,2-dibenzenesulfonamide-4-nitrobenzene; (2) Mix 1,2-dibenzenesulfonamide-4-nitrobenzene with hydrazine hydrate, palladium on carbon catalyst and solvent II, and react II to obtain intermediate A; (3) Intermediate A is mixed with dimethyl formaldehyde and solvent III, and reaction III is carried out to obtain intermediate B; (4) Intermediate B is mixed with solvent IV and reacted with IV to obtain a tetraamine monomer containing a Teleg base structure, 2,3,8,9-tetraamino-6H,12H-5,11-methylenediphenyl[b,f][1,5]-diaza-heterocyclic ring. (5) Mix the tetraamine monomer containing the telleg base structure with the diacid monomer and solvent V, react V, and obtain the polybenzimidazole containing the telleg base structure; The repeating unit of the polybenzimidazole containing the telrogal base structure has the structure shown in Formula I: Formula I; Where n is the degree of aggregation, and n is an integer between 1 and 500.

2. The preparation method according to claim 1, characterized in that, Solvent I is selected from at least one of pyridine, triethylamine, 2-methylpyridine, 3-methylpyridine, 2-ethylpyridine, or 3-ethylpyridine; The temperature of reaction I is 10–100°C; The reaction time for reaction I is 3–30 h; The molar ratio of 4-nitro-o-phenylenediamine to p-toluenesulfonyl chloride is 1:1 to 1:20; The total mass ratio of the 4-nitro-o-phenylenediamine and p-toluenesulfonyl chloride to solvent I is 1:1 to 1:

20.

3. The preparation method according to claim 1, characterized in that, Solvent II is selected from at least one of methanol, ethanol, tetrahydrofuran, dichloromethane, trichloromethane, or toluene; The temperature of reaction II is 30–100°C; The reaction time for reaction II is 2–20 h; The molar ratio of 1,2-dibenzenesulfonamide-4-nitrobenzene to hydrazine hydrate is 1:2 to 1:20; The mass ratio of the palladium catalyst on carbon to 1,2-dibenzenesulfonamide-4-nitrobenzene is 1:1 to 1:30; The total mass ratio of the 1,2-dibenzenesulfonamide-4-nitrobenzene, palladium on carbon catalyst, and hydrazine hydrate to solvent II is 1:1 to 1:

20.

4. The preparation method according to claim 1, characterized in that, Solvent III is selected from trifluoroacetic acid; The temperature of reaction III is -20 to 0°C; The reaction time for reaction III is 2–20 h; The molar ratio of intermediate A to dimethyl formaldehyde is 1:1 to 1:20; The total mass ratio of intermediate A and dimethylformaldehyde to solvent III is 1:2 to 1:

20.

5. The preparation method according to claim 1, characterized in that, The solvent IV is selected from at least one of concentrated sulfuric acid, concentrated nitric acid, concentrated hydrochloric acid, methanesulfonic acid, or trifluoromethanesulfonic acid; The temperature of reaction IV is 25–100°C; The reaction IV time is 2–20 h; The mass ratio of intermediate B to solvent IV is 1:2 to 1:

30.

6. The preparation method according to claim 1, characterized in that, The diacid monomer is selected from at least one of isophthalic acid, terephthalic acid, 4,4'-dicarboxylic acid diphenyl sulfone, 1,4-naphthalenedicarboxylic acid, 4,4'-dicarboxylic acid biphenyl, 2,2-bis(4-carboxyphenyl)hexafluoropropane or 4,4'-dicarboxylic acid diphenyl ether; The solvent V is selected from polyphosphoric acid; The temperature of reaction V is 150–250°C; The reaction time V is 5–50 h; The total mass ratio of the tetraamine monomer and diacid monomer containing the telrog base structure to the solvent V is 1:5 to 1:

100.

7. A polybenzimidazole containing a telrogal base structure prepared by the preparation method according to any one of claims 1 to 6.

8. A gas separation membrane, characterized in that, The polybenzimidazole containing the Teleg base structure as described in claim 7 is dissolved in an organic solvent to prepare a casting solution. The casting solution is then coated onto a glass plate, and the organic solvent is dried during a heat treatment process to obtain the gas separation membrane.

9. The gas separation membrane according to claim 8, characterized in that, The organic solvent is selected from at least one of N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide, m-cresol, and p-chlorophenol; The mass ratio of the polybenzimidazole containing the telrogal base structure described in claim 7 to the organic solvent is 1:5 to 1:

100.

10. The gas separation membrane according to claim 8, characterized in that, The heat treatment includes: treatment at 50–80°C for 2–30 hours under normal pressure, followed by treatment at 100–250°C for 1–20 hours under a pressure ≤0.02MPa.

Images