Green solid-phase synthesis method of polyarylether covalent organic framework material

Abstract

The invention relates to the technical field of synthesis of covalent organic framework materials, and discloses a green solid-phase synthesis method of a polyarylether covalent organic framework material, which comprises the following steps: carrying out melt polymerization reaction on an organic monomer A and an organic monomer B under the action of a fluxing agent, and purifying the reaction product to obtain the polyarylether covalent organic framework material, the organic monomer A is a tri-linking monomer or a hexa-linking monomer containing a sodium alkoxide functional group; the organic monomer B is a halogen substituent-containing two-linking monomer, three-linking monomer or four-linking monomer; the fluxing agent is a compound containing an anhydride functional group, an amino functional group or a carboxylic acid functional group. According to the method, the organic building blocks for constructing the COFs are regulated, controlled and screened, and the monomers are reasonably improved, so that solvent-free green synthesis of the polyarylether-based COF is realized; compared with a traditional solvothermal method, the method has the advantages that high-pressure conditions and generation of a large amount of waste liquid in the reaction process are avoided, the synthesis process of the polyarylether COFs is simplified, and the method is suitable for large-scale production of the polyarylether COFs.

Description

Technical Field

[0001] The present application relates to the technical field of synthesis of covalent organic framework materials, and in particular to a green solid-phase synthesis method of a polyarylether-based covalent organic framework material. Background Art

[0002] Covalent organic frameworks (COFs) are a type of framework polymer material composed of functional organic monomers connected by covalent bonds. They have the characteristics of low density, large specific surface area, high chemical stability, uniform pore size, and easy functionalization. Through the rational design of their structure, COFs have been widely used in the fields of adsorption separation, catalysis, energy, etc. The traditional synthesis methods of COFs mainly include solution polymerization, microwave-assisted synthesis, and solvent thermal synthesis. The synthesis process requires a large amount of organic solvents, high-pressure reaction conditions, and a large amount of waste liquid, causing environmental pollution. In addition to the above problems, when synthesizing polyarylether-based COFs, it is also necessary to precisely control the reaction conditions, such as temperature, pressure, type and concentration of initiators, etc. The above synthesis methods are restricted by the disadvantages of large solvent consumption, poor environmental friendliness, and difficulty in large-scale expansion, and it is difficult to meet the growing demand.

[0003] The melt polymerization method has shown great advantages in the preparation of polymer materials such as polyester and polyamide, and has achieved remarkable results in the large-scale industrial production of crystalline framework materials. At present, relevant researchers have explored the synthesis of COFs with imide bonds, vinyl bonds, hydrazone bonds, imide bonds, borate esters, borane oxygen hexacyclic bonds, azine bonds, and keto-enol bonds by flux. The melt synthesis method benefits from the participation of no solvent and avoids high-pressure reaction conditions, making COFs able to achieve large-scale production. However, it is limited by the melting point of the monomer and the type of reaction it can adapt to. It is difficult for high-melting-point monomers to form a molten state for reaction at a relatively low temperature, resulting in limited types of COFs that can be synthesized, and it is difficult to synthesize polyarylether-based COFs by the existing melt polymerization method.

[0004] Based on this, it is of great significance to develop new melt polymerization methods and apply them to the synthesis of polyarylether-based COFs. Summary of the invention

[0005] The present application provides a green solid-phase synthesis method for polyarylether-based covalent organic framework materials, aiming to solve the problem that polyarylether-based COFs are difficult to synthesize by the existing melt polymerization method.

[0006] In order to achieve the above objectives, the present application adopts the following technical solutions.

[0007] In a first aspect of the present application, a green solid phase synthesis method of a polyarylether-based covalent organic framework material is provided, comprising:

[0008] The organic monomer A and the organic monomer B are subjected to a melt polymerization reaction under the action of a flux, and the reaction product is purified to obtain a polyarylether-based covalent organic framework material;

[0009] The organic monomer A is a three-linked monomer or a six-linked monomer containing a sodium alcoholate functional group;

[0010] The organic monomer B is a di-linked monomer, a tri-linked monomer or a tetra-linked monomer containing a halogen substituent;

[0011] The flux is a compound containing anhydride functional groups, amino functional groups or carboxylic acid functional groups.

[0012] Preferably, the organic monomer A is sodium benzene-1,3,5-tri(alkoxide) or sodium triphenyl-2,3,6,7,10,11-hexa(alkoxide).

[0013] Preferably, the organic monomer B includes any one of p-phenylenedifluoride, p-phenylenedibromide, p-phenylenedichloride, 1,3,5-trichlorobenzene, 1,3,5-tribromobenzene, cyanuric chloride, 1,2,4,5-tetrafluorobenzene, 2,3,6,7-tetrafluoroanthracene-9,10-dione or 2,3,9,10-tetrafluoroquinoxaline[2,3-b]phenazine-6,13-dione.

[0014] Preferably, the flux includes at least one of benzoic anhydride, sodium benzoate, 4-trifluoromethylbenzoic anhydride, 4-methoxybenzoic anhydride, acetic anhydride, benzoic acid, 4-methylbenzoic acid, 4-aminoacetophenone, and methyl 4-aminobenzoate.

[0015] Preferably, the temperature of the melt polymerization reaction is 180-200° C., and the reaction time is 1-5 days.

[0016] Further preferably, it is characterized in that the melt polymerization reaction is carried out in a closed high-pressure resistant container, and the pressure of the melt polymerization reaction is ≤0.15 mmHg.

[0017] Preferably, the purification specifically comprises: washing the reaction product with DMF to remove unreacted monomers, then performing Soxhlet extraction in methanol to remove flux, and then drying at 80-100°C.

[0018] Preferably, the molar ratio of the organic monomer A to the organic monomer B is (2-4):1.

[0019] Preferably, the molar ratio of the flux to the organic monomer A is (1-10):1.

[0020] More preferably, the molar ratio of the flux to the organic monomer A is (6-8):1.

[0021] Compared with the prior art, the beneficial effects of this application are:

[0022] On the one hand, the present application realizes the solvent-free green synthesis of polyarylether-based COFs by regulating and screening the organic building blocks for constructing COFs and making reasonable improvements to the monomers; on the other hand, compared with the traditional solvothermal method, the solvent-free solid-phase melt synthesis method of the present application avoids the high-pressure operating conditions during the reaction and the generation of a large amount of waste liquid after the reaction, simplifies the synthesis process of polyarylether-based COFs, is safe and environmentally friendly, and is suitable for large-scale production of polyarylether-based COFs.

[0023] The polyarylether-based covalent porous organic framework material prepared in the present application has a pore size of 0.5 to 3.8 nm and has a high specific surface area, high porosity and high mechanical strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 The powder X-ray diffraction pattern of the polyarylether-based covalent organic framework material prepared in this application;

[0026] Figure 2 The infrared spectrum of the polyarylether-based covalent organic framework material prepared in this application;

[0027] Figure 3 77K nitrogen isothermal adsorption-desorption curve of the polyarylether-based covalent organic framework material prepared in this application;

[0028] Figure 4 A pore size distribution curve of a polyarylether-based covalent organic framework material prepared in this application;

[0029] Figure 5 This is a scanning electron microscope image of the polyarylether-based covalent organic framework material prepared in this application;

[0030] Figure 6 This is a thermogravimetric curve of the polyarylether-based covalent organic framework material prepared in this application. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0032] In the following description of this embodiment, the terms "include", "comprising", "having" and "containing" are all open terms, meaning including but not limited to.

[0033] In the following description of this embodiment, the term "and / or" is used to describe the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, B exists alone, and A and B exist at the same time. A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0034] In the following description of this embodiment, the term "at least one" refers to one or more, and "plurality" refers to two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b or c", or "at least one of a, b and c", can all represent: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, c can be single or multiple, respectively.

[0035] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "an" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0036] Those skilled in the art should understand that in the following description of the embodiments of the present application, the order of serial numbers does not mean the order of execution, some or all of the steps can be executed in parallel or sequentially, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0037] Those skilled in the art will appreciate that the numerical ranges in the embodiments of the present application are to be construed as specifically disclosing each intermediate value between the upper and lower limits of the scope. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present application. The upper and lower limits of these smaller ranges may be independently included or excluded in the scope.

[0038] Unless otherwise specified, the technical / scientific terms used herein have the same meanings as those generally understood by those skilled in the art to which this application belongs. Although this application only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of this application. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0039] The present application provides a green solid phase synthesis method of a polyarylether-based covalent organic framework material, comprising:

[0040] Organic monomer A and organic monomer B are subjected to melt polymerization reaction under the action of a flux, and the reaction product is purified to obtain a polyarylether-based covalent organic framework material.

[0041] In the present application, the organic monomer A is a three-linked monomer or a six-linked monomer containing a sodium alcoholate functional group, preferably sodium benzene-1,3,5-tri(alcoholate) or sodium triphenyl-2,3,6,7,10,11-hexa(alcoholate).

[0042] In the present application, the organic monomer B is a di-linked monomer, a tri-linked monomer or a tetra-linked monomer containing a halogen substituent. Among them, the di-linked monomer containing a halogen substituent includes any one of p-phenylenedifluoride, p-phenylenedibromide or p-phenylenedichloride; the tri-linked monomer containing a halogen substituent includes any one of 1,3,5-trichlorobenzene, 1,3,5-tribromobenzene or cyanuric chloride; the tetra-linked monomer containing a halogen substituent includes any one of 1,2,4,5-tetrafluorobenzene, 2,3,6,7-tetrafluoroanthracene-9,10-dione or 2,3,9,10-tetrafluoroquinoxaline [2,3-b] phenazine-6,13-dione.

[0043] In the present application, the flux is a compound containing anhydride functional groups, amino functional groups or carboxylic acid functional groups, including at least one of benzoic anhydride, sodium benzoate, 4-trifluoromethylbenzoic anhydride, 4-methoxybenzoic anhydride, acetic anhydride, benzoic acid, 4-methylbenzoic acid, 4-aminoacetophenone, and methyl 4-aminobenzoate.

[0044] In the present application, the melt polymerization reaction is preferably carried out in a closed high-pressure reaction vessel under negative pressure. The closed high-pressure reaction vessel can be a high-temperature and high-pressure resistant Pyrex tube, a flame-sealed ampoule, or a polytetrafluoroethylene-lined autoclave; the melt polymerization reaction pressure is preferably ≤ 0.15 mmHg; the melt polymerization reaction temperature is 180-200°C, and the reaction time is 1-5 days.

[0045] Specifically, organic monomer A, organic monomer B and flux are added to a high-pressure reaction vessel in proportion, and the pressure in the high-pressure reaction vessel is evacuated to 0.15 mmHg, the reaction system is closed, the reactor is heated to the reaction temperature and maintained for 1 to 5 days, and then the reactor is opened to purify the COFs material. The molar ratio of the organic monomer A to the organic monomer B is (2 to 4): 1; the molar ratio of the flux to the organic monomer A is (1 to 10): 1, preferably (6 to 8): 1. Under these conditions, polyarylether-based covalent organic framework materials can be successfully prepared.

[0046] In the present application, the purification is specifically as follows: washing the reaction product with DMF to remove unreacted monomers, then performing Soxhlet extraction in methanol to remove flux, and then drying at 80-100° C. to obtain a high-purity polyarylether-based covalent organic framework material.

[0047] This application achieves solvent-free green synthesis of polyarylether-based COFs by regulating and screening the organic building blocks for constructing COFs and making reasonable improvements to the monomers. Specifically, when synthesizing polyarylether-based covalent organic framework materials, organic monomer A uses sodium benzene-1,3,5-tri(alcohol), and organic monomer B can use a di-linked monomer with a halogen substituent or a tri-linked monomer with a halogen substituent, such as any one of p-phenylenedifluoride, p-phenylenedibromide, and p-phenylenedichloride. The general reaction formula is as follows:

[0048]

[0049] Wherein, X is F, Cl or Br;

[0050] When the organic monomer A is sodium benzene-1,3,5-tri(alcohol), the organic monomer B can also be a three-linked monomer with a halogen substituent, such as any one of 1,3,5-trichlorobenzene, 1,3,5-tribromobenzene or cyanuric chloride. The general reaction formula is as follows:

[0051]

[0052] Wherein, Y is Cl or Br;

[0053] When the organic monomer A is triphenyl-2,3,6,7,10,11-hexane sodium, the organic monomer B is a four-linked monomer containing a halogen substituent, such as any one of 1,2,4,5-tetrafluorobenzene, 2,3,6,7-tetrafluoroanthracene-9,10-dione or 2,3,9,10-tetrafluoroquinoxaline-[2,3-b]phenazine-6,13-dione.

[0054] Among them, the chemical formula of 2,3,6,7-tetrafluoroanthracene-9,10-dione is:

[0055]

[0056] The chemical formula of 2,3,9,10-tetrafluoroquinoxalino[2,3-b]phenazine-6,13-dione is:

[0057]

[0058] The general reaction formula is as follows:

[0059]

[0060] Compared with the traditional solvent thermal method, the solid phase melt synthesis method without solvent participation in this application avoids the high-pressure operating conditions during the reaction and the generation of a large amount of waste liquid after the reaction, simplifies the synthesis process of polyarylether-based COFs, is safe and environmentally friendly, and is suitable for large-scale production of polyarylether-based COFs. The pore size of the polyarylether-based covalent porous organic framework material prepared in this application is 0.5 to 3.8 nm, with high specific surface area, high porosity and high mechanical strength.

[0061] The present application is further described below by way of examples.

[0062] Example A Preparation of Sodium Benzene-1,3,5-Triol

[0063] 4 mmol of phloroglucinol was dissolved in 20 mL of anhydrous methanol to obtain solution A, and 12 mmol of NaOH was dissolved in 20 mL of anhydrous ethanol to obtain solution B; solution B and solution A were mixed evenly, and the mixture was heated to 90° C. to react for 4 hours; after the reaction was completed, the filtrate was collected by filtration, and the filtrate was evaporated to obtain a solid, and the solid was vacuum dried at 60° C. overnight to obtain sodium benzene-1,3,5-triol.

[0064] Example B Preparation of triphenyl-2,3,6,7,10,11-hexa(alkoxide)sodium

[0065] 0.8 mmol of triphenyl-2,3,6,7,10,11-hexanol was dissolved in 20 mL of anhydrous methanol to obtain solution A, and 4.8 mmol of NaOH was dissolved in 20 mL of anhydrous ethanol to obtain solution B; solution B and solution A were mixed evenly, and the mixture was heated to 90° C. for reaction for 4 hours; after the reaction was completed, the filtrate was collected by filtration, and the filtrate was evaporated to obtain a solid, and the solid was vacuum dried at 60° C. overnight to obtain triphenyl-2,3,6,7,10,11-hexane sodium.

[0066] Example 1

[0067] This embodiment provides a green solid phase synthesis method of a polyarylether-based covalent organic framework material, comprising:

[0068] Weigh 0.1mmol of triphenyl-2,3,6,7,10,11-hexane sodium, 0.15mmol of 2,3,9,10-tetrafluoroquinoxaline [2,3-b] phenazine-6,13-dione and 0.6mmol of benzoic acid, put them into a high temperature and high pressure resistant thick-walled glass tube, evacuate until the pressure of the thick-walled glass tube reaches 0.15mmHg, and seal the glass tube with the flame generated by the hydrogen generator to isolate the internal and external systems. Put the sealed glass tube into a 200℃ oven for reaction for 5 days, and obtain a brown-black block material after the reaction. After soaking it in DMF for 24h, Soxhlet extraction in methanol for 10h, and then drying it at 100℃ to obtain a brown powder material with a yield of about 89%, which is recorded as NKCOF-18.

[0069] Example 2

[0070] This embodiment provides a green solid phase synthesis method of a polyarylether-based covalent organic framework material, comprising:

[0071] Weigh 0.1mmol of triphenyl-2,3,6,7,10,11-hexane sodium, 0.15mmol of 2,3,6,7-tetrafluoroanthracene-9,10-dione and 0.6mmol of benzoic acid, put them into a high temperature and high pressure resistant thick-walled glass tube, evacuate until the pressure of the thick-walled glass tube reaches 0.15mmHg, and seal the glass tube with the flame generated by the hydrogen generator to isolate the internal and external systems. Put the sealed glass tube into a 200℃ oven for reaction for 5 days, and obtain a brown block material after the reaction. After soaking it in DMF for 24h, Soxhlet extraction in methanol for 10h, and then drying it at 100℃ to obtain a brown powder material with a yield of about 91%, recorded as JUC-506.

[0072] Example 3

[0073] This embodiment provides a green solid phase synthesis method of a polyarylether-based covalent organic framework material, comprising:

[0074] Weigh 0.1mmol of triphenyl-2,3,6,7,10,11-hexane sodium, 0.15mmol of 1,2,4,5-tetrafluorobenzene and 0.6mmol of benzoic acid, put them into a high temperature and high pressure resistant thick-walled glass tube, evacuate until the pressure of the thick-walled glass tube reaches 0.15mmHg, and seal the glass tube with the flame generated by the hydrogen generator to isolate the internal and external systems. Put the sealed glass tube into a 200℃ oven for reaction for 5 days, and obtain a brown-black block material after the reaction. After soaking it in DMF for 24h, Soxhlet extraction in methanol for 10h, and then drying it at 100℃ to obtain a brown-black powder material with a yield of about 90%, recorded as NKCOF-19.

[0075] Example 4

[0076] This embodiment provides a green solid phase synthesis method of a polyarylether-based covalent organic framework material, comprising:

[0077] Weigh 0.1mmol of sodium benzene-1,3,5-triol, 0.15mmol of 1,4-difluorobenzene and 0.6mmol of benzoic acid, put them into a high temperature and high pressure resistant thick-walled glass tube, evacuate until the pressure of the thick-walled glass tube reaches 0.15mmHg, and seal the glass tube with the flame generated by the hydrogen generator to isolate the internal and external systems. Put the sealed glass tube into a 180℃ oven for reaction for 5 days, and obtain a brown-black block material after the reaction. After soaking it in DMF, Soxhlet extraction in methanol lasts for 10 hours, and then dry it at 100℃ to obtain a brown-black block material with a yield of about 85%, recorded as TBS-DFB-COF.

[0078] Example 5

[0079] This embodiment provides a green solid phase synthesis method of a polyarylether-based covalent organic framework material, comprising:

[0080] Weigh 0.1mmol of sodium benzene-1,3,5-triol, 0.15mmol of 1,4-dichlorobenzene and 0.6mmol of benzoic acid, put them into a high temperature and high pressure resistant thick-walled glass tube, evacuate until the pressure of the thick-walled glass tube reaches 0.15mmHg, and seal the glass tube with the flame generated by the hydrogen generator to isolate the internal and external systems. Put the sealed glass tube into a 180℃ oven for reaction for 5 days, and obtain a brown-black block material after the reaction. After soaking it in DMF, Soxhlet extraction in methanol lasts for 10 hours, and then dry it at 100℃ to obtain a brown-black block material with a yield of about 82%, recorded as TBS-DCB-COF.

[0081] Example 6

[0082] This embodiment provides a green solid phase synthesis method of a polyarylether-based covalent organic framework material, comprising:

[0083] Weigh 0.1mmol of sodium benzene-1,3,5-triol, 0.15mmol of 1,4-dibromobenzene and 0.6mmol of benzoic acid, put them into a thick-walled glass tube resistant to high temperature and pressure, evacuate until the pressure of the thick-walled glass tube reaches 0.15mmHg, and seal the glass tube with the flame generated by the hydrogen generator to isolate the internal and external systems. Put the sealed glass tube into a 180℃ oven for reaction for 5 days, and obtain a brown-black block material after the reaction. After soaking it in DMF, Soxhlet extraction in methanol lasts for 10 hours, and then dry it at 100℃ to obtain a brown-black block material with a yield of about 84%, recorded as TBS-DBB-COF.

[0084] Example 7

[0085] This embodiment provides a green solid phase synthesis method of a polyarylether-based covalent organic framework material, comprising:

[0086] Weigh 0.1mmol of sodium benzene-1,3,5-triol, 0.1mmol of cyanuric chloride and 0.6mmol of benzoic acid, put them into a high temperature and high pressure resistant thick-walled glass tube, evacuate until the pressure of the thick-walled glass tube reaches 0.15mmHg, and seal the glass tube with the flame generated by the hydrogen generator to isolate the internal and external systems. Put the sealed glass tube into a 180℃ oven for reaction for 5 days, and obtain a brown-black block material after the reaction. After soaking it in DMF, Soxhlet extraction in methanol lasts for 10 hours, and then dry it at 100℃ to obtain a brown-black block material with a yield of about 80%, recorded as TBS-TCT-COF.

[0087] Example 8

[0088] This embodiment provides a green solid phase synthesis method of a polyarylether-based covalent organic framework material, comprising:

[0089] Weigh 0.1mmol of sodium benzene-1,3,5-triol, 0.15mmol of 1,3,5-trichlorobenzene and 0.6mmol of benzoic acid, put them into a thick-walled glass tube resistant to high temperature and pressure, evacuate until the pressure of the thick-walled glass tube reaches 0.15mmHg, and seal the glass tube with the flame generated by the hydrogen generator to isolate the internal and external systems. Put the sealed glass tube into a 180℃ oven for reaction for 5 days, and obtain a brown-black block material after the reaction. After soaking it in DMF, Soxhlet extraction in methanol lasts for 10 hours, and then dry it at 100℃ to obtain a brown-black block material with a yield of about 85%, recorded as TBS-TCB-COF.

[0090] Example 9

[0091] This embodiment provides a green solid phase synthesis method of a polyarylether-based covalent organic framework material, comprising:

[0092] Weigh 0.1mmol of benzene-1,3,5-tri(alcohol) sodium, 0.1mmol of 1,3,5-tribromobenzene and 0.6mmol of benzoic acid, put them into a high temperature and high pressure resistant thick-walled glass tube, evacuate until the pressure of the thick-walled glass tube reaches 0.15mmHg, and seal the glass tube with the flame generated by the hydrogen generator to isolate the internal and external systems. Put the sealed glass tube into a 180℃ oven for reaction for 5 days, and obtain a brown-black block material after the reaction. After soaking it in DMF, Soxhlet extraction in methanol lasts for 10 hours, and then dry it at 100℃ to obtain a brown-black block material with a yield of about 85%, recorded as TBS-TBB-COF.

[0093] The performance of the polyarylether-based covalent organic framework material NKCOF-18 prepared in Example 1 was characterized and its performance was evaluated.

[0094] 1. Powder X-ray diffraction test, the test results are as follows Figure 1 As shown. Figure 1 It can be seen that the obtained material NKCOF-18 has crystallinity.

[0095] 2. Infrared spectrum test, the results are as follows Figure 2 shown. Figure 2 Wherein monmer-1 is triphenyl-2,3,6,7,10,11-hexane sodium, monmer-2 is 2,3,9,10-tetrafluoroquinoxaline [2,3-b] phenazine-6,13-dione; Figure 2 It can be seen that NKCOF-18 is an ether bond connected COFs material, where 1631cm -1 The peak at corresponds to the stretching vibration of the carbon-oxygen single bond.

[0096] 3. Nitrogen isothermal adsorption and desorption test at 77K, the isothermal adsorption and desorption curve is as follows Figure 3 As shown. Figure 3 It can be seen that its BET surface area is 940m 2 / g, with high specific surface area.

[0097] 4. Pore size distribution test, the pore size distribution curve is as follows Figure 4 As shown. Figure 4 It can be seen that its pore size distribution is 1.2nm, which is a microporous material with high porosity.

[0098] 5. Scanning electron microscope test, the test picture is as follows Figure 5 As shown. Figure 5 It can be seen that the stacking of NKCOF-18 on the microscopic scale is irregular and the crystal particles are obvious.

[0099] 6. Thermogravimetric analysis, the thermogravimetric curve is as follows Figure 6 As shown. Figure 6 It can be seen that NKCOF-18 has excellent thermal stability and no obvious structural collapse occurs before 450°C.

[0100] The above shows that the present application simplifies the synthesis process of polyarylether-based COFs and realizes the solvent-free green synthesis of polyarylether-based COFs. The polyarylether-based covalent porous organic framework material prepared in the present application has a high specific surface area, high porosity and high mechanical strength.

[0101] Although the present application has been described in detail in general terms and in specific embodiments in this specification, it is obvious to those skilled in the art that some modifications or improvements may be made to the present application. Therefore, these modifications or improvements made without departing from the spirit of the present application are within the scope of protection claimed in the present application.

Claims

1. A green solid phase synthesis method of a polyarylether-based covalent organic framework material, characterized in that: include: The organic monomer A and the organic monomer B are subjected to a melt polymerization reaction under the action of a flux, and the reaction product is purified to obtain a polyarylether-based covalent organic framework material; The organic monomer A is a three-linked monomer or a six-linked monomer containing a sodium alcoholate functional group; The organic monomer B is a di-linked monomer, a tri-linked monomer or a tetra-linked monomer containing a halogen substituent; The flux is a compound containing anhydride functional groups, amino functional groups or carboxylic acid functional groups.

2. The green solid phase synthesis method according to claim 1, characterized in that: The organic monomer A is sodium benzene-1,3,5-tri(alkoxide) or sodium triphenyl-2,3,6,7,10,11-hexa(alkoxide).

3. The green solid phase synthesis method according to claim 1, characterized in that: The organic monomer B includes any one of p-phenylenedifluoride, p-phenylenedibromide, p-phenylenedichloride, 1,3,5-trichlorobenzene, 1,3,5-tribromobenzene, cyanuric chloride, 1,2,4,5-tetrafluorobenzene, 2,3,6,7-tetrafluoroanthracene-9,10-dione or 2,3,9,10-tetrafluoroquinoxaline [2,3-b] phenazine-6,13-dione.

4. The green solid phase synthesis method according to claim 1, characterized in that: The flux includes at least one of benzoic anhydride, sodium benzoate, 4-trifluoromethylbenzoic anhydride, 4-methoxybenzoic anhydride, acetic anhydride, benzoic acid, 4-methylbenzoic acid, 4-aminoacetophenone, and methyl 4-aminobenzoate.

5. The green solid phase synthesis method according to claim 1, characterized in that: The temperature of the melt polymerization reaction is 180-200° C., and the reaction time is 1-5 days.

6. The green solid phase synthesis method according to claim 5, characterized in that: The melt polymerization reaction is carried out in a closed high-pressure resistant container, and the pressure of the melt polymerization reaction is ≤0.15 mmHg.

7. The green solid phase synthesis method according to claim 1, characterized in that: The purification specifically includes: washing the reaction product with DMF to remove unreacted monomers, then performing Soxhlet extraction in methanol to remove flux, and then drying at 80-100°C.

8. The green solid phase synthesis method according to claim 1, characterized in that: The molar ratio of the organic monomer A to the organic monomer B is (2-4):

1.

9. The green solid phase synthesis method according to claim 1, characterized in that: The molar ratio of the flux to the organic monomer A is (1-10):

1.

10. The green solid phase synthesis method according to claim 9, characterized in that: The molar ratio of the flux to the organic monomer A is (6-8):1.

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