Polybenzimidazoles, process for their preparation and their use

Abstract

The present invention provides a new class of polybenzimidazole polymers that exhibit excellent gas adsorption separation properties, while also having mechanochromic properties. The polybenzimidazole polymers of the present invention can be used for the adsorption separation of carbon dioxide containing gases.

Description

Technical Field

[0001] This invention relates to the field of polymer materials, and more particularly to polybenzimidazole containing tetraphenylethylene groups, methods for separating gases by adsorption using the same, and its use for the adsorption and separation of gases. Background Technology

[0002] Polybenzimidazole (PBI) is a class of heterocyclic polymers containing an imidazole ring in repeating units, and it has excellent thermal stability, mechanical stability and chemical stability.

[0003] Polymers, due to their excellent processing properties, are often processed into membrane products such as nanofiltration membranes and hollow fiber membranes for gas separation and purification. Although they offer excellent separation performance, polymer membrane products typically lack adsorption capabilities. This invention provides a novel polybenzimidazole polymer that exhibits good gas adsorption performance and different adsorption selectivity for different gases. Summary of the Invention

[0004] The purpose of this invention is to provide a novel polybenzimidazole polymer with gas adsorption and separation properties. Furthermore, the polybenzimidazole polymer of this application exhibits mechanochromic properties.

[0005] The first aspect of the present invention provides a polybenzimidazole containing a structural unit A having the structure shown in formula (1);

[0006]

[0007] Wherein, the X1 group is a linking group provided by an aromatic compound containing 1-10 benzene rings; and the Y group is a linking group based on tetraphenylethylene; wherein, the X1 group and the Y group each have or do not have at least one substituent selected from hydroxyl, amino, cyano, halogen, C1-C4 alkyl, and C1-C4 haloalkyl.

[0008] In some embodiments, the polybenzimidazole contains structural units A and C, contains structural units A and D, or contains structural units A, B, C and D.

[0009] Wherein structural unit A has the structure shown in equation (1), structural unit B has the structure shown in equation (2), structural unit C has the structure shown in equation (1-1), and structural unit D has the structure shown in equation (2-2):

[0010]

[0011] Wherein, X1 and X2 groups are each independently provided as linking groups for aromatic compounds containing 1-10 benzene rings; Y group is a linking group based on tetraphenylethylene; and Z group is an aromatic hydrocarbon containing 1-10 benzene rings, a heterocyclic aromatic hydrocarbon containing 1-10 heterocycles, an aromatic hydrocarbon containing 1-3 heterocycles and 1-8 benzene rings, or a C4-C4 aromatic hydrocarbon. 10 The linking group is provided by at least one compound selected from cycloalkanes, C1-C8 alkanes, and C2-C8 alkenes; wherein each of the X1, X2, Y, and Z groups has or does not have at least one substituent selected from hydroxyl, amino, cyano, halogen, C1-C4 alkyl, and C1-C4 haloalkyl.

[0012] In some embodiments, the polybenzimidazole contains structural unit A and optional structural unit B, wherein structural unit A has the structure shown in formula (1) and structural unit B has the structure shown in formula (2);

[0013]

[0014] Wherein, X1 and X2 groups are each independently provided as linking groups for aromatic compounds containing 1-10 benzene rings; Y group is a linking group based on tetraphenylethylene; and Z group is an aromatic hydrocarbon containing 1-10 benzene rings, a heterocyclic aromatic hydrocarbon containing 1-10 heterocycles, an aromatic hydrocarbon containing 1-3 heterocycles and 1-8 benzene rings, or a C4-C4 aromatic hydrocarbon. 10 The linking group is provided by at least one compound selected from cycloalkanes, C1-C8 alkanes, and C2-C8 alkenes, and Z and Y are different when structural unit B is present; wherein, each of the X1, X2, Y and Z groups has or does not have at least one substituent selected from hydroxyl, amino, cyano, halogen, C1-C4 alkyl, and C1-C4 haloalkyl.

[0015] The present invention also provides a method for preparing the polybenzimidazole of the present invention, the method comprising reacting at least one compound having the structure shown in formula (6) with HOOC-Y-COOH and optionally HOOC-Z-COOH;

[0016]

[0017] Wherein, the X group in formula (6) is the same as the X1 and / or X2 groups defined in the first aspect, and the Y and Z groups in HOOC-Y-COOH and optional HOOC-Z-COOH are each the same as the Y and Z groups defined in the first aspect.

[0018] The present invention also provides a method for separating CO2 gas by adsorption, wherein the polybenzimidazole of the present invention is used as an adsorbent.

[0019] The present invention also provides the use of the polybenzimidazole of the present invention as an adsorbent for gas adsorption and separation. Attached Figure Description

[0020] Figure 1 These are the 1H NMR spectra of polymer (PBI-1) from Example 1 and polymer (PBI-2) from Example 2.

[0021] Figure 2 This is a graph of the free volume probability distribution function of PBI-4.

[0022] Figure 3 These are fluorescence spectra of PBI-2 before and after grinding.

[0023] Figure 4 The images show the physical photos of the non-inventory polybenzimidazole polymer (left) and the polymer of Example 4 (PBI-4, right). Detailed Implementation

[0024] The first aspect of the present invention provides a polybenzimidazole, the polybenzimidazole containing a structural unit A having the structure shown in formula (1);

[0025]

[0026] Wherein, the X1 group is a linking group provided by an aromatic compound containing 1-10 benzene rings; and the Y group is a linking group based on tetraphenylethylene; wherein, the X1 group and the Y group each independently have or do not have at least one substituent selected from hydroxyl, amino, cyano, halogen, C1-C4 alkyl, and C1-C4 haloalkyl. In some embodiments, the polybenzimidazole is composed of structural unit A.

[0027] In some embodiments, the polybenzimidazole contains structural units A and C, contains structural units A and D, or contains structural units A, B, C and D.

[0028] Wherein structural unit A has the structure shown in equation (1), structural unit B has the structure shown in equation (2), structural unit C has the structure shown in equation (1-1), and structural unit D has the structure shown in equation (2-2):

[0029]

[0030] Wherein, X1 and X2 groups are each independently provided as linking groups for aromatic compounds containing 1-10 benzene rings; Y group is a linking group based on tetraphenylethylene; and Z group is an aromatic hydrocarbon containing 1-10 benzene rings, a heterocyclic aromatic hydrocarbon containing 1-10 heterocycles, an aromatic hydrocarbon containing 1-3 heterocycles and 1-8 benzene rings, or a C4-C4 aromatic hydrocarbon. 10 The linking group is provided by at least one compound selected from cycloalkanes, C1-C8 alkanes, and C2-C8 alkenes; wherein at least one substituent selected from hydroxyl, amino, cyano, halogen, C1-C4 alkyl, and C1-C4 haloalkyl is independently present or absent on each of the X1, X2, Y, and Z groups. In some embodiments, the polybenzimidazole is composed of structural unit A and structural unit C. In some embodiments, the polybenzimidazole is composed of structural unit A and structural unit D. In some embodiments, the polybenzimidazole is composed of structural unit A, structural unit B, structural unit C, and structural unit D.

[0031] In some embodiments, the polybenzimidazole contains structural unit A and optional structural unit B, wherein structural unit A has the structure shown in formula (1) and structural unit B has the structure shown in formula (2);

[0032]

[0033] Wherein, X1 and X2 groups are each independently provided as linking groups for aromatic compounds containing 1-10 benzene rings; Y group is a linking group based on tetraphenylethylene; Z group is an aromatic hydrocarbon containing 1-10 benzene rings, a heterocyclic aromatic hydrocarbon containing 1-10 heterocycles, an aromatic hydrocarbon containing 1-3 heterocycles and 1-8 benzene rings, or a C4-C4 aromatic hydrocarbon. 10 The linking group is provided by at least one of cycloalkanes, C1-C8 alkanes and C2-C8 alkenes, and Z is different from Y when structural unit B is present; wherein, X1, X2, Y and Z groups are each independently present or absent at least one substituent selected from hydroxyl, amino, cyano, halogen, C1-C4 alkyl and C1-C4 haloalkyl.

[0034] In this invention, those skilled in the art will understand the connection method of the X1 and X2 groups in formulas (1) and (2). For example, when the X1 and X2 groups are each independently a connecting group provided by benzene, the structural formulas of formulas (1) and (2) can be respectively... That is, the benzene ring and the imidazole ring share two pairs of carbon atoms.

[0035] In this invention, C4-C 10 Cycloalkanes can be, for example, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclononane, or cyclodecane.

[0036] In this invention, the C1-C8 alkanes may be, for example, methane, ethane, n-propane, isopropane, butane, pentane, hexane, heptane, or octane. In some embodiments, the C1-C8 alkanes may be C1-C8 alkanes substituted with one or more halogen atoms, wherein the halogen atoms may be selected from fluorine, chlorine, and bromine atoms.

[0037] In this invention, the C2-C8 olefins may be, for example, ethylene, propylene, butene, pentene, hexene, hepten, or octene.

[0038] In this invention, halogens may be selected from fluorine, chlorine and bromine, for example.

[0039] In this invention, C1-C4 alkyl groups can be, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, or tert-butyl.

[0040] In this invention, C1-C4 haloalkyl groups may be, for example, halomethyl, haloethyl, halopropyl, haloisopropyl, halobutyl, halosec-butyl, haloisobutyl, or halotert-butyl; and the halogen atom in the C1-C4 haloalkyl group may be, for example, a fluorine atom, a chlorine atom, or a bromine atom.

[0041] According to the present invention, preferably, in some embodiments, the X1 and X2 groups are each independently provided by a linking group of at least one compound selected from benzene, biphenyl, terphenyl, bridged benzene, pterene, and fused-ring aromatic hydrocarbons containing 1-10 benzene rings; preferably, the X1 and X2 groups are each independently provided by a linking group of at least one compound selected from benzene, biphenyl, bridged benzene, pterene, and naphthalene; more preferably, the bridged benzene has the structure shown in formula (3), formula (4), or formula (5), wherein R1, R3, and R4 are each independently selected from one of an oxygen atom, a sulfur atom, a carbonyl group, a sulfonyl group, a methylene group, and a halogen-substituted methylene group; and R2 is selected from a heterocyclic aromatic ring.

[0042]

[0043] In this invention, the heterocyclic aromatic ring may be, for example, pyridine or pyrimidine.

[0044] In this invention, the connection positions (indicated by "dashed lines") of the structures shown in equations (3), (4), and (5) can be as follows:

[0045]

[0046] In this invention, the connection positions include, but are not limited to, the above representations; for example, any two adjacent connection positions on the same benzene ring are feasible.

[0047] According to the present invention, preferably, the X1 and X2 groups are each independently selected from the following linking groups:

[0048]

[0049] Wherein, G is selected from hydrogen atom, methyl and trifluoromethoxy; J is selected from oxygen atom, sulfur atom, carbonyl, sulfonyl, methylene and methyl or trifluoromethyl substituted methylene; L is selected from bromine atom, phenyl and trifluoromethyl substituted phenyl; and R is selected from hydrogen atom, carboxyl, hydroxyl and trifluoromethyl.

[0050] In some embodiments of the present invention, the connection positions of the X1 and X2 groups may include, but are not limited to, the following connection positions:

[0051]

[0052] According to the present invention, in some embodiments, the molar ratio of the X2 and X1 groups can be 0-9999, preferably 0-99; for example, it can be 0, 0.001, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 99, 100, and any range consisting of any two of the above points. In the present invention, unless otherwise specified, the content ratio of the X2 and X1 structural units or groups in polybenzimidazole is calculated based on the amount of feed.

[0053] According to the present invention, preferably, the Y group is derived from at least one of the following compounds:

[0054]

[0055] According to the present invention, preferably, in some embodiments, the Z group is benzene, a 5-6 member nitrogen-containing heterocyclic compound, an aromatic compound containing 2-7 benzene rings, an aromatic compound containing 1-2 nitrogen-containing heterocycles and 1-4 benzene rings, or a C4-C4 compound. 10 The linking group is provided by a compound of at least one of cycloalkanes, C1-C8 alkanes, and C2-C8 alkenes.

[0056] According to the present invention, preferably, the Z group is a linking group selected from the following:

[0057]

[0058]

[0059] C1-C8 chain alkyl;

[0060] Wherein, M is selected from hydrogen atom, cyano, methyl, phenyl and methyl or trifluoromethyl substituted phenyl; P is selected from oxygen atom, sulfur atom, carbonyl, sulfonyl, cyclobutyl, halogen-substituted cyclobutyl, methylene and methyl or trifluoromethyl substituted methylene; Q is selected from bromine atom, phenyl and trifluoromethyl substituted phenyl; and T is selected from hydrogen atom and methyl.

[0061] In this invention, the connection position of the Z group is not particularly limited and can be any position on the connecting group. For example, when the Z group contains a cyclic structure, the connection position can be a carbon atom on the cyclic structure; when the Z group is a C1-C8 alkyl chain, the connection position can be any carbon atom in the alkyl chain. In this invention, the connection position of the Z group can include, but is not limited to, the following connection positions:

[0062]

[0063]

[0064] According to the present invention, the molar ratio of the Z and Y groups can be 0-9999, more preferably 0-99; for example, it can be 0, 0.001, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 99, 100, and any two of the above ranges. In the present invention, unless otherwise specified, the content ratio of the Z and Y structural units or groups in polybenzimidazole is calculated based on the amount of feed.

[0065] In this invention, the free volume of the polybenzimidazole can be... Preferred And the pore size of the polybenzimidazole can be Preferred

[0066] In this invention, the intrinsic viscosity of the polybenzimidazole can be 0.45-3.0 dL / g. -1 For example, it could be 0.45 dL g. -1 0.5 dL g -1 0.6 dL g -1 0.7dL g -1 0.8 dL g -1 0.9dL g -1 1dL g -1 1.1dL g -1 1.2 dL g-1 1.3dL g -1 1.4 dL g -1 1.5 dL g -1 1.6 dL g -1 1.7dL g -1 1.8dL g -1 1.9dL g -1 2.0 dL g -1 2.1dL g -1 2.2dL g -1 2.3dL g -1 2.4 dL g -1 2.5 dL g -1 2.6 dL g -1 2.7 dL g -1 2.8 dL g -1 2.9dL g -1 3.0 dL g -1 , and the range formed by any two of the above points.

[0067] The preparation of polybenzimidazole is known in the art. Various preparation methods known in the art can be used to prepare the polybenzimidazole of the present invention.

[0068] In another aspect, the present invention also provides a method for preparing the polybenzimidazole described in the first aspect, the method comprising reacting at least one compound having the structure shown in formula (6) with HOOC-Y-COOH and optionally HOOC-Z-COOH;

[0069]

[0070] In formula (6), the X group is the same as the X1 and / or X2 groups in formula (1) and formula (2) above, and the Y and Z groups in HOOC-Y-COOH and optional HOOC-Z-COOH are the same as the Y and Z groups defined in formula (1) and formula (2) above, which will not be repeated here.

[0071] According to the preparation method of the present invention, preferably, in some embodiments, the compound having the structure shown in formula (6) is selected from at least one of the following compounds:

[0072]

[0073] Wherein, G is selected from hydrogen atom, methyl and trifluoromethoxy, namely -H, -CH3, -OCF3;

[0074] J is selected from oxygen atom, sulfur atom, carbonyl group, sulfonyl group, methylene group, and methylene group substituted with methyl or trifluoromethyl, for example,

[0075] L is selected from phenyl groups substituted with bromine atoms, phenyl groups, and trifluoromethyl groups, for example, as well as

[0076] R is selected from hydrogen atom, carboxyl group, hydroxyl group and trifluoromethyl, namely -H, -COOH, -OH, -CF3.

[0077] According to the preparation method of the present invention, preferably, in some embodiments, the reaction is carried out in a solvent; more preferably, the solvent is a mixed solution of methanesulfonic acid / phosphorus pentoxide or polyphosphoric acid, and even more preferably a mixed solution of methanesulfonic acid / phosphorus pentoxide, wherein the mass of phosphorus pentoxide is 2-10% of the mass of methanesulfonic acid. The concentration of the mixed monomers in the reaction system can be 3wt%-20wt%.

[0078] According to the preparation method of the present invention, preferably, in some embodiments, the molar ratio of the compound having the structure shown in formula (6) to the total molar ratio of HOOC-Y-COOH and optionally HOOC-Z-COOH is 1:0.6-2, preferably 1:0.8-1.2.

[0079] According to the preparation method of the present invention, preferably, in some embodiments, the reaction time can be 1-9 hours, more preferably 3-5 hours. The reaction temperature can be 60-230°C, more preferably 60-170°C, and more preferably 100-150°C. The reaction pressure can be atmospheric pressure.

[0080] According to the preparation method of the present invention, preferably, HOOC-Y-COOH is selected from at least one of the following compounds:

[0081]

[0082] According to the preparation method of the present invention, preferably, in some embodiments, HOOC-Z-COOH is selected from at least one of the following compounds:

[0083]

[0084]

[0085] Where n is 1-8; M, P, Q, and T each refer to substituents, which are the same as those described in the first aspect, and will not be repeated here.

[0086] According to the preparation method of the present invention, preferably, in some embodiments, the molar ratio of the compound having the structure shown in formula (6) to the total molar ratio of HOOC-Y-COOH and optionally HOOC-Z-COOH is 1:0.6-2; for example, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, and any two of the above ranges; preferably 1:0.8-1.2; wherein the molar ratio of X2 to X1 groups can be 0-9999, preferably 0-99, for example, 0, 0.001, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.0 The range includes 9, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 99, 100, and any two of the above. The molar ratio of Z to Y groups can be 0-9999, preferably 0-99, for example, 0 or 0.001. 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 99, 100, and the range formed by any two of the above points.

[0087] In some embodiments, the polybenzimidazole of the present invention may have one of the following structures:

[0088]

[0089] In the structures shown above, for copolymers, the shown structure only indicates that the polymer chain segment contains the shown repeating structural unit or that the polymer chain segment is composed of the shown repeating structural unit, and does not indicate the distribution of the shown repeating structural unit in the polymer chain. This invention also provides the application of the above-described polybenzimidazole polymer in gas adsorption and separation.

[0090] In one aspect, the present invention provides a method for separating CO2 gas by adsorption, wherein the polybenzimidazole described in the first aspect of the present invention is used as an adsorbent.

[0091] In this invention, it was unexpectedly discovered that the polybenzimidazole of this invention has a high adsorption capacity for CO2 and a low adsorption capacity for N2 and O2, thereby providing a high carbon dioxide / nitrogen separation coefficient and a high carbon dioxide / oxygen separation coefficient, making it suitable for separating CO2 from gases selected from N2, O2, or mixtures thereof.

[0092] This invention does not limit the specific separation operation, but generally includes contacting the polybenzimidazole of this invention with a gas mixture containing CO2. When the polybenzimidazole of this invention adsorbs a sufficient amount of CO2, the polybenzimidazole can be removed and desorbed for regeneration. The regenerated polybenzimidazole can then be contacted again with a gas mixture containing CO2 to adsorb CO2.

[0093] The present invention also provides the use of the polybenzimidazole described in the first aspect of the invention as an adsorbent for gas adsorption and separation. Because the polybenzimidazole of the present invention has a high adsorption capacity for CO2 and a low adsorption capacity for N2 and O2, the polybenzimidazole of the present invention can be used as an adsorbent to separate CO2 from gases selected from N2, O2, or mixtures thereof.

[0094] This invention provides a polybenzimidazole polymer with beneficial gas adsorption and separation properties, and it has excellent thermal stability, making it suitable for gas adsorption and separation applications in some high-temperature conditions.

[0095] Furthermore, the polybenzimidazole polymer of the present invention exhibits mechanochromic properties. Mechanochromic materials are those whose color, luminescence, and other properties change when subjected to external forces, such as grinding, stretching, and pressing. The polybenzimidazole polymer of the present invention shows a significant shift in its fluorescence emission peak under external force stimulation, thus constituting a mechanochromic material.

[0096] In some embodiments, the polybenzimidazole of the present invention can be used for flow monitoring of carbon dioxide-containing gases. For example, the polybenzimidazole of the present invention can be coated on the inner surface of a microchannel and placed at the end of the gas path where the flow rate or emission of carbon dioxide needs to be monitored. When there is a slight leak of carbon dioxide, it can absorb the carbon dioxide through its adsorption properties; when the amount of carbon dioxide leaking increases, the impact of the flow causes the material to be stressed, resulting in a change in the fluorescence emission peak signal, which is then captured by the detector, thereby triggering an alarm.

[0097] Polybenzimidazole without tetraphenylethylene groups is generally reddish-brown, while polybenzimidazole with tetraphenylethylene groups is generally yellow. The introduction of tetraphenylethylene groups increases the color diversity of polybenzimidazole and can expand its application scenarios. Figure 4Physical images of a non-inventive polybenzimidazole polymer (left side; prepared using 3,3′,4,4′-tetraaminobiphenyl and 4,4′-diphenyl ether dicarboxylic acid in a molar ratio of 1:1.05 in a manner similar to that described in the embodiments of this application) and the polymer of Example 4 (PBI-4, right side) are shown.

[0098] To make the present invention easier to understand, the present invention will be described in detail below with reference to embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of application of the present invention. It should be noted that reasonable modifications made by those skilled in the art based on this patent are all within the protection scope of this patent.

[0099] In the following embodiments,

[0100] The yield of the polymerization product is calculated using the following formula:

[0101] Yield = Actual polymer yield ÷ Theoretical polymer yield × 100%;

[0102] Wherein, the theoretical yield of the polymer = the number of moles of the compound shown in equation (6) × the molar mass of the repeating unit in the polymer structure.

[0103] 3,3′,4,4′-Tetraaminobiphenyl: Sigma-Aldrich; purity 98%;

[0104] 4,4′-Diphenyl ether dicarboxylic acid: Bailingwei Technology; purity 98%;

[0105] 4,4′-(2,2-diphenylvinyl-1,1-diyl)dibenzoic acid: Anaiji Chemical, purity 98%;

[0106] 4,4′-(1,2-diphenylvinyl-1,2-diyl)dibenzoic acid: Anaiji Chemical, purity 91%.

[0107] Example 1

[0108] A mixture of monomers in a molar ratio of 1:0.735:0.315, consisting of 2.14 g of 3,3′,4,4′-tetraaminobiphenyl, 1.9 g of 4,4′-diphenyl ether dicarboxylic acid, and 1.32 g of 4,4′-(2,2-diphenylethylene-1,1-diyl)benzoic acid, was added to a methanesulfonic acid / phosphorus pentoxide solution (62 g solvent) to form a reaction system. The reaction was carried out at 140 °C for 5 h to obtain a reaction solution. The reaction solution was then introduced into water to precipitate the polymer, followed by neutralization (with sodium bicarbonate) and filtration to obtain the polymer product PBI-1. The weight ratio of methanesulfonic acid to phosphorus pentoxide in the methanesulfonic acid / phosphorus pentoxide solution was 12:1, and the concentration of the mixed monomers in the reaction system was 8 wt%. The polymer yield was 99%. The 1H NMR spectrum of PBI-1 was measured in Test Example 6. Figure 1The structure is shown in the figure. Its structure was confirmed by 1H NMR spectroscopy.

[0109] Example 2

[0110] The procedure was followed according to Example 1, except that 4,4′-(2,2-diphenylethylene-1,1-diyl)benzoic acid was replaced with an equimolar amount of 4,4′-(1,2-diphenylethylene-1,2-diyl)benzoic acid. The yield of polymer PBI-2 was 99%. The 1H NMR spectrum of PBI-2 was measured in Test Example 6. Figure 1 The structure is shown in the figure. Its structure was confirmed by 1H NMR spectroscopy.

[0111] Example 3

[0112] The procedure was carried out according to Example 1, except that 4,4′-diphenyl ether dicarboxylic acid was replaced with an equimolar amount of 4,4′-(2,2-diphenylethylene-1,1-diyl)dibenzoic acid, and the reaction time was 3 h. The yield of polymer PBI-3 was 99%. Its structure was confirmed by 1H NMR spectroscopy.

[0113] Example 4

[0114] The procedure was carried out according to Example 1, except that 4,4′-diphenyl ether dicarboxylic acid was replaced with an equimolar amount of 4,4′-(1,2-diphenylethylene-1,2-diyl)dibenzoic acid, and the reaction time was 3 h. The yield of polymer PBI-4 was 99%. Its structure was confirmed by 1H NMR spectroscopy.

[0115] Test Example 1

[0116] The thermal stability of the polymers prepared in the above examples was tested.

[0117] Test method: The test was conducted using a TA Q500 thermogravimetric analyzer in a nitrogen atmosphere. The heating rate was 10℃ / min, and the temperature range was 25-700℃.

[0118] The thermal decomposition temperature T of the polymer d5 The percentage (temperature at which 5% of mass is lost) is shown in Table 1.

[0119] Table 1

[0120] PBI-1 PBI-2 PBI-3 PBI-4 <![CDATA[T d5 %(℃)]]> 490 530 510 490

[0121] Test Example 2

[0122] Free volume and pore size were determined using positron annihilation lifetime spectroscopy.

[0123] Test method: Positron annihilation lifetime spectra were measured using a DPLS3000 in an atmospheric environment at room temperature and pressure. The activity used was approximately 2E. +6A Bq-based 22Na positron emission source was sandwiched between the sample to form a sandwich structure. A total of 1.5 million counts were performed to obtain the positron annihilation lifetime spectrum of the sample. The system had a time resolution of 190 ps, ​​a channel width of 20 ps, ​​and 4096 channels. The measured positron annihilation lifetime spectrum was interpreted using the Melt 4.0 program to obtain the positron annihilation lifetime and intensity, as well as the polymer free volume and pore size.

[0124] The results of polymer free volume and pore size tests are shown in Table 2.

[0125] Table 2

[0126]

[0127] Test Example 3

[0128] The isothermal adsorption properties of polybenzimidazole on gases were tested.

[0129] Test method: The test was conducted using the ASAP2020 analyzer from Micromeritics. The sample was placed in a sample tube and subjected to high-temperature vacuum degassing at a degassing station. After degassing, the sample was weighed and placed in the analysis station. Adsorption and desorption isotherms for N2, O2, and CO2 were measured at room temperature. The pressure range for adsorption isotherms was selected from 10 mmHg to 800 mmHg, and the pressure range for desorption isotherms was selected from 800 mmHg to 60 mmHg.

[0130] The test results are shown in Table 3.

[0131] Table 3

[0132]

[0133] Test Example 4

[0134] The mechanochromic properties of the polymers prepared in Examples 1-4 above were tested.

[0135] Test method: The polymer powder was placed in a solid fixture (two transparent quartz plates, one of which had a groove for placing the sample) and then placed in a fluorescence spectrometer (Edinburgh-FLS1000 steady-state / transient fluorescence spectrometer) to detect the fluorescence emission spectrum. Then, the polymer powder was manually ground in a mortar for 30 seconds and placed in the solid fixture again, and the fluorescence emission spectrum was detected again.

[0136] The shifts of the strongest fluorescence emission peak before and after polymer grinding are shown in Table 4.

[0137] Table 4

[0138]

[0139] Note: "#" indicates a blue shift of the emission peak; "*" indicates a red shift of the emission peak.

[0140] Test Example 5

[0141] The intrinsic viscosity of the polymers prepared in Examples 1-4 above was tested.

[0142] Test method: Dissolve PBI in concentrated sulfuric acid to prepare a solution with a concentration of 0.6 g dL- 1 Sulfuric acid solution. The sulfuric acid solution was added to an Ubbelohde viscometer and stabilized in a 25°C water bath for 30 minutes. The outflow time of the solution was measured. Each sample was measured three times, with a time difference not exceeding 1 second. The average value was recorded as t1, and the outflow time of concentrated sulfuric acid was recorded as t0. The intrinsic viscosity [η] of PBI is calculated using the following formula: Specific viscosity. Intrinsic viscosity Where C is the concentration of the PBI sulfuric acid solution.

[0143] The test results are shown in Table 5.

[0144] Table 5

[0145] PBI-1 PBI-2 PBI-3 PBI-4 <![CDATA[ Intrinsic viscosity (dL g -1 )]]> 2.18 1.08 1.75 2.01

[0146] Test Example 6

[0147] The proton NMR spectra of the polymers from Examples 1 and 2 were tested. The proton NMR spectra were measured using an Agilent 400-MR DD2 NMR spectrometer at a frequency of 400 MHz, with tetramethylsilane (TMS) as the internal standard, DMSO-d6 as the solvent, and a test temperature of 40 °C.

[0148] The 1H NMR spectra of the polymerization products of Examples 1 and 2 are as follows: Figure 1 As shown in the spectrum, the proton signal at chemical shift 13.0 ppm can be attributed to the characteristic peak of active hydrogen in the PBI structural unit; the proton signals at 7.30 ppm and 8.28 ppm can be attributed to the characteristic peaks of the corresponding structural units after polymerization of 4,4′-diphenyl ether dicarboxylic acid monomer; and the proton signals at 7.08–7.24 ppm and 7.55–8.02 ppm can be attributed to the characteristic peaks of the corresponding structural units after polymerization of tetraamine monomer and tetraphenylethylene diacid monomer, respectively. Spectral analysis results indicate the successful acquisition of polymers PBI-1 and PBI-2.

[0149] The results of the proton NMR spectrum indicate that polymers PBI-1 to PBI-4 were successfully obtained.

[0150] Comparative Example 1

[0151] The data reported in the following literature were used:

[0152] Facile preparation of porous polybenzimidazole networks and adsorption behavior of CO2 gas, organic and water vapors, Hao Yu et al., Polym. Chem., 2013, 4, 961-968 (DOI: 10.1039 / c2py20908j)

[0153] The experiment in this paper used Autosorb iQ-MP testing to measure the adsorption isotherms of the gas at room temperature, with a pressure limit of 1 bar. The test results are shown in Table 6.

[0154] Table 6

[0155] PBI-1' PBI-2' Separation coefficient (carbon dioxide / nitrogen) 12.3 9.3

[0156] Comparative Example 2

[0157] The data reported in the following literature were used:

[0158] Influence of polybenzimidazole main chain structure on H2 / CO2separation at elevated temperatures, Xin Li et al, Journal of MembraneScience, Volume 461, 1July 2014, Pages 59-68 (DOI: 10.1016 / j.memsci.2014.03.008)

[0159] The experiment in this paper used Kalrez TM The tests were conducted at pressures ranging from 10 to 50 psi and temperatures from 30 to 250°C. The test results are shown in Table 7.

[0160] Table 7

[0161]

[0162] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A polybenzimidazole, characterized in that, The polybenzimidazole contains structural unit A, which has the structure shown in formula (1); Equation (1) Wherein, the X1 group is a linking group provided by an aromatic compound containing 1-10 benzene rings; and the Y group is a linking group based on tetraphenylethylene; wherein, the X1 group and the Y group each have or do not have at least one substituent selected from hydroxyl, amino, cyano, halogen, C1-C4 alkyl, and C1-C4 haloalkyl.

2. The polybenzimidazole according to claim 1, wherein, The polybenzimidazole contains structural unit A and structural unit C, contains structural unit A and structural unit D, or contains structural unit A, structural unit B, structural unit C and structural unit D; Wherein structural unit A has the structure shown in equation (1), structural unit B has the structure shown in equation (2), structural unit C has the structure shown in equation (1-1), and structural unit D has the structure shown in equation (2-2): Wherein, X1 and X2 groups are each independently provided as linking groups for aromatic compounds containing 1-10 benzene rings; Y group is a linking group based on tetraphenylethylene; and Z group is an aromatic hydrocarbon containing 1-10 benzene rings, a heterocyclic aromatic hydrocarbon containing 1-10 heterocycles, an aromatic hydrocarbon containing 1-3 heterocycles and 1-8 benzene rings, or a C4-C4 aromatic hydrocarbon. 10 The linking group is provided by at least one compound selected from cycloalkanes, C1-C8 alkanes, and C2-C8 alkenes; wherein each of the X1, X2, Y, and Z groups has or does not have at least one substituent selected from hydroxyl, amino, cyano, halogen, C1-C4 alkyl, and C1-C4 haloalkyl.

3. The polybenzimidazole according to claim 1, wherein, The polybenzimidazole contains structural unit A and optional structural unit B, wherein structural unit A has the structure shown in formula (1) and structural unit B has the structure shown in formula (2); Wherein, X1 and X2 groups are each independently provided as linking groups for aromatic compounds containing 1-10 benzene rings; Y group is a linking group based on tetraphenylethylene; and Z group is an aromatic hydrocarbon containing 1-10 benzene rings, a heterocyclic aromatic hydrocarbon containing 1-10 heterocycles, an aromatic hydrocarbon containing 1-3 heterocycles and 1-8 benzene rings, or a C4-C4 aromatic hydrocarbon. 10 The linking group is provided by at least one compound selected from cycloalkanes, C1-C8 alkanes, and C2-C8 alkenes, and Z and Y are different when structural unit B is present; wherein, each of the X1, X2, Y and Z groups has or does not have at least one substituent selected from hydroxyl, amino, cyano, halogen, C1-C4 alkyl, and C1-C4 haloalkyl.

4. The polybenzimidazole according to any one of claims 1-3, wherein, The X1 and X2 groups are each independently provided by a linking group from at least one of benzene, diphenyl, terphenyl, bridged benzene, pterene, and fused-ring aromatic hydrocarbons containing 1 to 10 benzene rings.

5. The polybenzimidazole according to claim 4, wherein, The X1 and X2 groups are each independently provided by a linking group from at least one compound selected from benzene, biphenyl, bridged benzene, pterene, and naphthalene.

6. The polybenzimidazole according to claim 4, wherein, The bridged benzene has the structure shown in formula (3), formula (4) or formula (5), wherein R1, R3, and R4 are each independently selected from oxygen atom, sulfur atom, carbonyl group, sulfonyl group, methylene group and halogen-substituted methylene group; and R2 is selected from heteroaromatic rings; 。 7. The polybenzimidazole according to claim 5, wherein, The bridged benzene has the structure shown in formula (3), formula (4) or formula (5), wherein R1, R3, and R4 are each independently selected from oxygen atom, sulfur atom, carbonyl group, sulfonyl group, methylene group and halogen-substituted methylene group; and R2 is selected from heteroaromatic rings; 。 8. The polybenzimidazole according to any one of claims 1-3, wherein, The X1 and X2 groups are each independently selected from the following linking groups: Wherein, G is selected from hydrogen atom, methyl and trifluoromethoxy; J is selected from oxygen atom, sulfur atom, carbonyl, sulfonyl, methylene and methyl or trifluoromethyl substituted methylene; L is selected from bromine atom, phenyl and trifluoromethyl substituted phenyl; and R is selected from hydrogen atom, carboxyl, hydroxyl and trifluoromethyl.

9. The polybenzimidazole according to any one of claims 2-3, wherein, The Z group is benzene, a 5-6 member nitrogen-containing heterocyclic compound, an aromatic compound containing 2-7 benzene rings, an aromatic compound containing 1-2 nitrogen-containing heterocycles and 1-4 benzene rings, or a C4-C4 compound. 10 The linking group is provided by a compound of at least one of cycloalkanes, C1-C8 alkanes, and C2-C8 alkenes.

10. The polybenzimidazole according to any one of claims 2-3, wherein, The Z group is selected from the following linking groups: C1-C8 alkyl groups; Wherein, M is selected from hydrogen atom, cyano, methyl, phenyl, and methyl or trifluoromethyl substituted phenyl; P is selected from oxygen atom, sulfur atom, carbonyl, sulfonyl, cyclobutyl, halogen-substituted cyclobutyl, methylene and methyl or trifluoromethyl substituted methylene; Q is selected from bromine atom, phenyl and trifluoromethyl substituted phenyl; and T is selected from hydrogen atom and methyl.

11. The polybenzimidazole according to any one of claims 1-3, wherein, The Y group is derived from at least one of the following compounds: 。 12. The polybenzimidazole according to any one of claims 1-3, wherein, The intrinsic viscosity of the polybenzimidazole is 0.45-3.0 dL / g. -1 ; and / or, The molar ratio of X2 to X1 groups in the polybenzimidazole is 0-9999; and / or, The molar ratio of Z to Y groups in the polybenzimidazole is 0-9999.

13. The polybenzimidazole according to claim 12, wherein... The molar ratio of X2 to X1 groups in the polybenzimidazole is 0-99; and / or, The molar ratio of Z to Y groups in the polybenzimidazole is 0-99.

14. The polybenzimidazole according to any one of claims 1-3, wherein, The free volume of the polybenzimidazole is 80-120 Å. 3 ; and the pore size of the polybenzimidazole is 2.5-3.5 Å.

15. The polybenzimidazole according to any one of claims 1-3, wherein, The free volume of the polybenzimidazole is 85-110 Å. 3 ; and the pore size of the polybenzimidazole is 2.6-3.2 Å.

16. The polybenzimidazole according to any one of claims 1-3, wherein, The polybenzimidazole has mechanochromic properties.

17. A method for preparing polybenzimidazole according to any one of claims 1-16, wherein the method comprises reacting at least one compound having the structure shown in formula (6) with HOOC-Y-COOH and optionally HOOC-Z-COOH; in, The X group in formula (6) is the same as the X1 and / or X2 groups defined in any one of claims 1-16, and the Y and Z groups in HOOC-Y-COOH and optional HOOC-Z-COOH are each the same as the Y and Z groups defined in any one of claims 1-16.

18. The method of claim 17, wherein the reaction is carried out in a solvent.

19. The method of claim 18, wherein the solvent is a mixed solution of methanesulfonic acid / phosphorus pentoxide or polyphosphoric acid.

20. The method according to claim 18, wherein the solvent is a mixed solution of methanesulfonic acid and phosphorus pentoxide, and the mass of phosphorus pentoxide is 2-10% of the mass of methanesulfonic acid.

21. The method according to claim 17 or 18, wherein the molar ratio of the compound having the structure shown in formula (6) to the total molar ratio of HOOC-Y-COOH and optionally HOOC-Z-COOH is 1:0.6-2.

22. The method according to claim 17 or 18, wherein the molar ratio of the compound having the structure shown in formula (6) to the total molar ratio of HOOC-Y-COOH and optionally HOOC-Z-COOH is 1:0.8-1.

2.

23. A method for separating CO2 gas by adsorption, wherein polybenzimidazole as described in any one of claims 1-16 is used as the adsorbent.

24. The method of claim 23, wherein the CO2 gas is separated from a gas selected from N2, O2, or mixtures thereof by adsorption.

25. Use of polybenzimidazole as an adsorbent according to any one of claims 1-16 for gas adsorption separation, wherein polybenzimidazole is used as an adsorbent to separate CO2 gas from a gas selected from N2, O2, or mixtures thereof.

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