阅读说明：本技术 一种柱[5]芳烃交联含氟聚芳醚阴离子交换膜及其制备方法 (Column [5] arene cross-linked fluorine-containing polyarylether anion exchange membrane and preparation method thereof ) 是由 陈栋阳 赵梦依 江海 陈煜� 于 2020-06-18 设计创作，主要内容包括：本发明属于离子交换膜材料领域,具体涉及一种柱[5]芳烃交联含氟聚芳醚阴离子交换膜及其制备方法。本发明先通过叔胺化双酚芴、双酚芴和十氟联苯的缩聚反应合成含氟聚芳醚化合物,再加入十溴丙基柱[5]芳烃作为交联剂,浇铸成膜。接着,将所得膜浸泡在碘甲烷水溶液中进行季胺化,即得柱[5]芳烃交联含氟聚芳醚阴离子交换膜。通过改变交联剂十溴丙基柱[5]芳烃的投料量,可得不同交联程度和微观结构的阴离子交换膜。本发明所涉及的合成工艺简单,制得的阴离子交换膜交联度高,且具有较高的阴离子传导率、良好的尺寸稳定性、机械性能和热稳定性。(The invention belongs to the field of ion exchange membrane materials, and particularly relates to a column [5] arene cross-linked fluorine-containing polyarylether anion exchange membrane and a preparation method thereof. The invention firstly synthesizes fluorine-containing polyarylether compound by the polycondensation reaction of tertiary amination bisphenol fluorene, bisphenol fluorene and decafluorobiphenyl, and then decabromopropyl column [5] arene is added as a cross-linking agent to cast into a film. And then, soaking the membrane in a methyl iodide aqueous solution for quaternization to obtain the column [5] arene cross-linked fluorine-containing polyarylether anion exchange membrane. By changing the feeding amount of the cross-linking agent decabromopropyl column [5] arene, anion exchange membranes with different cross-linking degrees and microstructures can be obtained. The synthesis process is simple, and the prepared anion exchange membrane has high crosslinking degree, high anion conductivity, good dimensional stability, mechanical property and thermal stability.)

1. The column [5] arene cross-linked fluorine-containing polyarylether anion exchange membrane is characterized in that a fluorine-containing polyarylether compound synthesized by condensation polymerization of tertiary aminated bisphenol fluorene, bisphenol fluorene and decafluorobiphenyl is used as a precursor of the anion exchange membrane, decabromopropyl column [5] arene is used as a cross-linking agent, part of amine groups on the fluorine-containing polyarylether compound react with bromopropyl on the decabromopropyl column [5] arene to be cross-linked and simultaneously generate quaternary ammonium salt cationic groups, and the remaining amine groups on the fluorine-containing polyarylether compound react with iodomethane to introduce the quaternary ammonium salt cationic groups to prepare the column [5] arene cross-linked fluorine-containing polyarylether anion exchange membrane.

2. The preparation method of the column [5] arene cross-linked fluorine-containing polyarylether anion exchange membrane according to claim 1, which is characterized by comprising the following steps:

(1) dissolving tertiary aminated bisphenol fluorene, bisphenol fluorene and decafluorobiphenyl in a polar aprotic solvent to prepare a solution of 15-20 wt.%, adding cesium fluoride as a catalyst and calcium hydride as a water removal agent, and carrying out polymerization reaction for 12-36h at room temperature under the protection of inert gas; after the reaction is finished, slowly pouring the product into deionized water to separate out a precipitate, filtering, collecting the precipitate, and drying in a vacuum oven at 60 ℃ for 12-36 h; dissolving the obtained solid in dichloromethane to prepare 1-10wt.% solution, and slowly pouring into methanol to precipitate out precipitate, wherein the volume of the methanol is 5-50 times of that of the dichloromethane; filtering, collecting precipitate, and drying in a vacuum oven at 60-80 deg.C for 12-36h to obtain fluorine-containing polyarylether compound;

the chemical structure of the tertiary aminated bisphenol fluorene is as follows:

；

the fluorine-containing polyarylether compound has the following chemical structural formula:

；

wherein m is 1-400 and n is 10-400.

(2) At room temperature, dissolving decabromopropyl column [5] arene in a polar aprotic solvent, and fully stirring to completely dissolve the decabromopropyl column [5] arene to prepare 1-10wt.% decabromopropyl column [5] arene solution;

the chemical structural formula of the decabromopropyl column [5] arene is as follows:

；

(3) at room temperature, dissolving the fluorine-containing polyarylether compound obtained in the step (1) in a polar aprotic solvent to prepare 1-10wt.% of fluorine-containing polyarylether solution, then adding the decabromopropyl column [5] arene solution prepared in the step (2), and stirring to enable the fluorine-containing polyarylether compound and the decabromopropyl column [5] arene to perform a cross-linking reaction to obtain a casting solution; then, casting the casting solution on a horizontally placed glass plate, and drying in a common oven at 60-100 ℃ for 12-36h to obtain a layer of compact film on the surface of the glass plate; when the glass plate is cooled to room temperature, the film is removed from the surface of the glass plate;

(4) soaking the compact film obtained in the step (3) in 0.05-0.5M methyl iodide aqueous solution at room temperature, sealing in the dark, stirring for 3-7 d, carrying out quaternization reaction, taking out the film, and soaking in deionized water A to wash away excessive methyl iodide; and finally, soaking the membrane in a 1M NaCl aqueous solution for ion exchange reaction, then soaking the membrane in deionized water B, and washing away redundant NaCl to obtain the column [5] arene cross-linked fluorine-containing polyarylether anion exchange membrane.

3. The preparation method according to claim 2, wherein the tertiary aminated bisphenol fluorene, decafluorobiphenyl, cesium fluoride and calcium hydride in the step (1) are in a molar ratio of x:1-x:1: 3-6: 0.01-1, wherein 0< x < 1; the mass ratio of the polar aprotic solvent to the decafluorobiphenyl is 5-50: 1; the volume ratio of the deionized water to the polar aprotic solvent is 100-1000: 1.

4. The method according to claim 2, wherein the molar amount of the decabromopropyl column [5] arene used in the step (2) is 0.005 to 0.05 times of the molar amount of the amine group contained in the fluorine-containing polyarylether compound obtained in the step (1).

5. The preparation method according to claim 2, wherein the stirring in the step (3) is specifically stirring at room temperature for 0.5-2 h.

6. The production method according to claim 2, wherein the thickness of the dense film of the step (3) is 30 to 300 μm.

7. The method according to claim 2, wherein the polar aprotic solvent is any one of N, N-dimethylacetamide, N-dimethylformamide, N-methylpyrrolidone, and dimethylsulfoxide.

8. The method according to claim 2, wherein the immersion in deionized water A in step (4) is carried out under conditions of: soaking for 12-36h at 60 ℃; the soaking in 1M NaCl water solution is specifically soaking at 60 ℃ for 12-36 h.

9. The method according to claim 2, wherein the molar amount of methyl iodide in step (4) is 1 to 10 times that of the amine group in the fluorine-containing polyarylether compound.

10. The method according to claim 2, wherein the ratio of the volume of the deionized water A to the mass of the membrane in step (4) is 100-1000:1 (mL/g); the ratio of the volume of the deionized water B to the mass of the membrane is 100-1000:1 (mL/g); the ratio of the volume of the 1M NaCl aqueous solution to the mass of the membrane was 100-1000:1 (mL/g).

Technical Field

The invention relates to a column [5] arene cross-linked fluorine-containing polyarylether anion exchange membrane and a preparation method thereof, belonging to the field of ion exchange membrane materials.

Background

The anion exchange membrane is a functional polymer electrolyte membrane and consists of a polymer skeleton, cation groups connected to the polymer skeleton and movable anions. The polymer skeleton determines the mechanical property, thermal stability and dimensional stability of the anion exchange membrane; the cation groups determine the ion exchange and conduction functions of the anion exchange membrane; the anions can be exchanged and conducted.

An ideal anion exchange membrane should have excellent mechanical stability, thermal stability, dimensional stability, high ionic conductivity, and the like; in order to increase the anion conductivity of an anion exchange membrane, the most direct method is to increase the ion exchange capacity of the membrane. However, there is a problem that an excessive ion exchange capacity causes an increase in the swelling ratio and water absorption of the anion exchange membrane, and the internal structure of the membrane is destroyed, thereby causing a decrease in the mechanical properties of the membrane. Therefore, the balance of anion conductivity and mechanical properties is a problem that anion exchange membranes need to solve in practical applications.

Building crosslinked structures in anion exchange membranes is the most straightforward and effective way to balance mechanical properties and anion conductivity. The crosslinking can form a network structure in the polymer so as to inhibit the swelling rate and water absorption of the membrane and improve the chemical stability and mechanical properties of the membrane. Therefore, the method for improving the performance of the membrane by crosslinking modification is provided, and has important significance for the development of high-performance anion exchange membranes. However, the current crosslinking method still has the following problems: 1. the cross-linking agent has irritation, toxicity and mutagenicity. 2. The crosslinking process is complex and the reaction speed is slow. The crosslinking can be carried out only by the initiation of specific conditions such as catalyst, high temperature, photochemistry and the like, and side reaction or toxic and harmful substances are generated in the crosslinking process. 3. The crosslinked structure is unstable at high temperatures. 4. The crosslinked structure severely reduces the anionic conductivity.

Aiming at the problems, the polyarylether compound with high mechanical strength and chemical stability is selected as a main chain, decabromopropyl column [5] arene with dense polyfunctional groups is selected as a cross-linking agent, and haloalkane and an amino polymer precursor are subjected to nucleophilic substitution reaction to be cross-linked; the cross-linking method is simple and convenient to operate, can obviously improve the mechanical property of a membrane material, and is the cross-linking strategy most commonly adopted in the field of anion exchange membranes; the whole preparation process does not need to design special functional groups for crosslinking, the reaction is simple and easy to implement, the time consumption is short, no side reaction exists, the crosslinking can be carried out at room temperature, the operation is simple, the method is a green route for preparing the high-performance anion exchange membrane without a halomethylation step, and the problem that the halomethylation reagent has high toxicity is solved; decabromopropyl column [5] arene is used as a cross-linking agent, and under the condition of extremely low feed ratio, the activity of a polymer chain is effectively limited, the water absorption rate is effectively inhibited, good dimensional stability, mechanical properties, chemical stability and the like are maintained, and the anion exchange membrane with excellent comprehensive properties is prepared.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a column [5] arene cross-linked fluorine-containing polyarylether anion exchange membrane. The anion exchange membrane has the advantages of simple preparation process, high ion conductivity, good mechanical property, good chemical stability and the like, and has huge development prospect in the field of anion exchange membrane materials.

In order to achieve the purpose, the invention adopts the following technical scheme:

a column [5] arene cross-linked fluorine-containing polyarylether anion exchange membrane is characterized in that a fluorine-containing polyarylether compound synthesized by condensation polymerization of tertiary aminated bisphenol fluorene, bisphenol fluorene and decafluorobiphenyl is used as a precursor, decabromopropyl column [5] arene is used as a cross-linking agent, part of amine groups on the fluorine-containing polyarylether compound react with bromopropyl groups on the decabromopropyl column [5] arene to be cross-linked, quaternary ammonium salt cation groups are generated at the same time, and the remaining amine groups on the fluorine-containing polyarylether compound react with methyl iodide to introduce the quaternary ammonium salt cation groups, so that the column [5] arene cross-linked fluorine-containing polyarylether anion exchange membrane is prepared.

The invention also aims to provide a preparation method of the column [5] arene cross-linked fluorine-containing polyarylether anion exchange membrane, which specifically comprises the following steps:

(1) dissolving tertiary aminated bisphenol fluorene, bisphenol fluorene and decafluorobiphenyl in a polar aprotic solvent to prepare 1520 wt% solution, adding cesium fluoride as a catalyst and adding calcium hydride as a water removal agent; carrying out polymerization reaction for 12-36h at room temperature under the protection of inert gas; after the reaction is finished, slowly pouring the product into deionized water to separate out a precipitate, filtering, collecting the precipitate, and drying in a vacuum oven at 60 ℃ for 12-36 h; dissolving the obtained solid in dichloromethane to prepare 110 wt.% solution, and slowly pouring into methanol to precipitate out precipitate, wherein the volume of the methanol is 5-50 times of that of the dichloromethane; filtering, collecting precipitate, and drying in a vacuum oven at 60-80 deg.C for 12-36h to obtain fluorine-containing polyarylether compound;

the tertiary aminated bisphenol fluorene reference described above (Journal of Polymer Science Part A Polymer chemistry,2016,54(7):935-944) was synthesized and has the following chemical structure:

the reaction formula of the above polymerization process is shown below:

wherein m is 1 to 400 and n is 10 to 400.

(2) At room temperature, dissolving decabromopropyl column [5] arene in a polar aprotic solvent, and fully stirring to completely dissolve the decabromopropyl column [5] arene to prepare a 1-10 wt% decabromopropyl column [5] arene solution; the molar weight of the decabromopropyl column [5] arene is 0.005-0.05 time of the molar weight of the amino group in the fluorine-containing polyarylether compound obtained in the step (1).

The above decabromopropyl column [5] arene reference (Journal of the American chemical society,2016,138(3): 754-:

(3) and (2) at room temperature, dissolving the fluorine-containing polyarylether compound obtained in the step (1) in a polar aprotic solvent to obtain 1-10 wt% of fluorine-containing polyarylether solution, adding the decabromopropyl column [5] arene solution prepared in the step (2), and stirring at room temperature for 1h to perform a crosslinking reaction on the fluorine-containing polyarylether compound and the decabromopropyl column [5] arene to obtain a membrane casting solution. Then, casting the casting solution on a horizontally placed glass plate, and drying in a common oven at 60-100 ℃ for 12-36h to obtain a layer of compact film on the surface of the glass plate, wherein the thickness of the film is 30-300 microns; after the glass plate is cooled to room temperature, the film is removed from the surface of the glass plate.

(4) Soaking the compact film obtained in the step (3) in 0.05-0.5M methyl iodide aqueous solution at room temperature, sealing in the dark, stirring for 3-7 d, carrying out quaternization reaction, taking out the film, soaking in deionized water A at 60 ℃ for 12-36h, and washing off excessive methyl iodide; and finally, soaking the membrane in 1MNaCl aqueous solution for 12-36h at 60 ℃, performing ion exchange reaction, soaking with deionized water B, and washing off redundant NaCl to obtain the column [5] arene cross-linked fluorine-containing polyarylether anion exchange membrane. The ratio of the volume of the deionized water A to the mass of the membrane is 100-1000:1 (mL/g); the ratio of the volume of the deionized water B to the mass of the membrane is 100-1000:1 (mL/g); the ratio of the volume of the 1M NaCl aqueous solution to the mass of the membrane was 100-1000:1 (mL/g).

The structural schematic diagram of the column [5] arene cross-linked fluorine-containing polyarylether anion exchange membrane is as follows:

the mole ratio of the tertiary aminated bisphenol fluorene, decafluorobiphenyl, cesium fluoride and calcium hydride in the step (1) is x:1-x:1: 3-6: 0.01-1, wherein x is more than 0 and less than 1; the mass ratio of the polar aprotic solvent to the decafluorobiphenyl is 5-50: 1; the volume ratio of the deionized water to the polar aprotic solvent is 100-1000: 1.

The polar aprotic solvent in the above step is any one of N, N-dimethylacetamide, N-dimethylformamide, N-methylpyrrolidone, and dimethylsulfoxide.

In the step (4), the molar weight of the methyl iodide is 1-10 times of that of the amino group in the fluorine-containing polyarylether compound.

The invention relates to a column [5] arene cross-linked fluorine-containing polyarylether anion exchange membrane, which takes decabromopropyl column [5] arene as a cross-linking agent, directly carries out nucleophilic substitution reaction with amino on fluorine-containing polyarylether compound to be cross-linked, and simultaneously carries out quaternization. The residual amido and the haloalkyl are quaternized through methylation reaction after film forming to prepare the column [5] arene cross-linked fluorine-containing polyarylether anion exchange membrane, and the membrane material shows excellent stability.

Compared with the prior art, the invention has the following beneficial effects:

(1) decabromopropyl column [5] arene is used as a cross-linking agent, and the mobility of a polymer chain can be effectively limited under the condition of low feed ratio, so that the cross-linking efficiency is high.

(2) Decabromopropyl column [5] arene is used as a cross-linking agent, the cross-linking point is highly concentrated, the non-cross-linking chain segment is longer, and the structure of the obtained cross-linked product is different from that of the traditional cross-linking agent. This particular structure is advantageous for optimizing the relationship between the degree of crosslinking and the properties of the membrane.

(3) The haloalkyl reacts with the amido polymer precursor to crosslink, no special functional group is needed to crosslink, the reaction is simple and easy to implement, the time consumption is short, no side reaction exists, the crosslinking can be carried out at room temperature, and the operation is simple.

(4) The crosslinking degree can be controlled by changing the feeding ratio of the crosslinking agent, and the prepared crosslinked membrane has the advantages of high anion conductivity, high dimensional stability, high mechanical property and thermal stability and the like, and has excellent comprehensive properties.

Drawings

FIG. 1 is a nuclear magnetic resonance hydrogen spectrum of a fluorine-containing polyarylether compound FPAE60 in example 1;

FIG. 2 is a nuclear magnetic resonance hydrogen spectrum of a fluorine-containing polyarylether compound FPAE80 in example 2;

FIG. 3 is an infrared spectrum of a polyarylether anion exchange membrane containing fluorine cross-linked with arene [5] in example 6;

FIG. 4 is a thermogravimetric analysis diagram of column [5] arene cross-linked fluorine-containing polyarylether anion exchange membrane.

Detailed Description

In order to make the present invention more comprehensible, the technical solutions of the present invention are further described below with reference to specific embodiments, but the present invention is not limited thereto.