A green solid-phase synthesis method of poly(arylene ether)-based covalent organic frameworks

Abstract

The application relates to the technical field of covalent organic framework material synthesis, and discloses a green solid-phase synthesis method of polyarylether-based covalent organic framework material, which comprises the following steps: carrying out a melt polymerization reaction of organic monomer A and organic monomer B under the action of a fluxing agent, and obtaining a polyarylether-based covalent organic framework material through purification of a reaction product; the organic monomer A is a three-connected monomer or a six-connected monomer containing a sodium alcoholate functional group; the organic monomer B is a two-connected monomer, a three-connected monomer or a four-connected monomer containing a halogen substituent; and the fluxing agent is a compound containing an acid anhydride functional group, an amino functional group or a carboxylic acid functional group. Through regulation and screening of organic building blocks for constructing COFs and reasonable improvement of monomers, the application realizes solvent-free green synthesis of polyarylether-based COFs; compared with a traditional solvothermal method, the application avoids high-pressure conditions and generation of a large amount of waste liquid in the reaction process, simplifies a synthesis process of the polyarylether-based COFs, and is suitable for large-scale production of the polyarylether-based COFs.

Description

Technical Field

[0001] This application relates to the field of covalent organic framework material synthesis technology, specifically to a green solid-phase synthesis method for polyarylether-based covalent organic framework materials. Background Technology

[0002] Covalent organic frameworks (COFs) are framework polymer materials composed of functional organic monomers linked by covalent bonds. They possess characteristics such as low density, large specific surface area, high chemical stability, uniform pore size, and ease of functionalization. Through rational structural design, COFs have found wide applications in adsorption separation, catalysis, and energy. Traditional methods for synthesizing COFs mainly include solution polymerization, microwave-assisted synthesis, and solvothermal synthesis. These methods require large amounts of organic solvents, high-pressure reaction conditions, and generate significant amounts of waste liquid, causing environmental pollution. Furthermore, the synthesis of polyarylether-based COFs requires precise control of reaction conditions, such as temperature, pressure, and the type and concentration of initiators. These synthetic methods are limited by high solvent consumption, poor environmental friendliness, and difficulty in large-scale scaling, making it difficult to meet the ever-increasing demand.

[0003] Melt polymerization has demonstrated significant advantages in the preparation of polymer materials such as polyesters and polyamides, and has achieved remarkable results in the large-scale industrial production of crystalline framework materials. Currently, researchers have explored flux-synthesized COFs with imine, vinyl, hydrazone, imide, borate ester, borooxyhexacyclic, azazine, and keto-enol linkages. Melt polymerization benefits from the absence of solvents, avoiding high-pressure reaction conditions, thus enabling large-scale production of COFs. However, it is limited by the melting point of monomers and the type of reaction required. High-melting-point monomers are difficult to react in a molten state at relatively low temperatures, limiting the types of COFs that can be synthesized and making it difficult to synthesize polyarylether-based COFs using existing melt polymerization methods.

[0004] Therefore, developing new melt polymerization methods and applying them to the synthesis of polyarylene ether-based COFs is of great significance. Summary of the Invention

[0005] This 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 through existing melt polymerization methods.

[0006] To achieve the above objectives, the present application adopts the following technical solution.

[0007] A first aspect of this application provides a green solid-phase synthesis method for polyarylether-based covalent organic framework materials, comprising:

[0008] Organic monomers A and B are melt-polymerized in the presence 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 tri- or hexa-linked monomer containing a sodium alkoxide functional group;

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

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

[0012] Preferably, the organic monomer A is sodium phenyl-1,3,5-triol or sodium triphenyl-2,3,6,7,10,11-hexanediol.

[0013] Preferably, the organic monomer B comprises any one of terephthalic acid difluoroethylene, terephthalic acid dibromo, terephthalic acid dichloroethylene, 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-tetrafluoroquinoxalino[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℃, and the reaction time is 1~5 days.

[0016] More preferably, the melt polymerization reaction is carried out in a sealed, high-pressure resistant container, and the pressure of the melt polymerization reaction is ≤0.15 mmHg.

[0017] Preferably, the purification specifically includes: washing the reaction product with DMF to remove unreacted monomers, then Soxhlet extracting it in methanol to remove flux, and then drying it at 80~100℃.

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

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

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

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

[0022] This application achieves solvent-free green synthesis of polyarylether-based COFs by regulating and screening the organic building blocks used to construct COFs and by reasonably improving the monomers. On the other hand, compared with traditional solvothermal methods, the solvent-free solid-phase melt synthesis method avoids high-pressure operating conditions 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 polyarylene ether-based covalent porous organic framework material prepared in this application has a pore size of 0.5~3.8 nm and exhibits high specific surface area, high porosity, and high mechanical strength. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a 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 polyarylene ether-based covalent organic framework material prepared in this application;

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

[0028] Figure 4 Pore ​​size distribution curves of the polyarylene ether-based covalent organic framework material prepared in this application;

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

[0030] Figure 6 Thermogravimetric curve of the polyarylether-based covalent organic framework material prepared in this application. Detailed Implementation

[0031] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

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

[0033] In the following description of this embodiment, the term "and / or" is used to describe the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, B existing alone, and A and B existing simultaneously. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

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

[0035] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms "a" and "the" as used in the embodiments of this application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0036] Those skilled in the art should understand that, in the following description of the embodiments of this application, the sequence of numbers does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. 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 this application.

[0037] Those skilled in the art will understand that the numerical ranges in the embodiments of this application should be understood as each intermediate value between the upper and lower limits of the specifically disclosed range. Each smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this application. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0038] Unless otherwise stated, the technical / scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. While this application describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this application. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0039] This application provides a green solid-phase synthesis method for polyarylether-based covalent organic framework materials, comprising:

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

[0041] In this application, the organic monomer A is a tri- or hexa-linked monomer containing a sodium alkoxide functional group, preferably sodium benzene-1,3,5-triol or sodium triphenyl-2,3,6,7,10,11-hexaol.

[0042] In this application, the organic monomer B is a di-, tri-, or tetra-linked monomer containing a halogen substituent. Specifically, the di-linked monomer containing a halogen substituent includes any one of terephthalofluoride, terephthalobromo, or terephthalochloro; the tri-linked monomer containing a halogen substituent includes any one of 1,3,5-trichlorobenzene, 1,3,5-tribromobenzene, or cyanuric chloride; and 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-tetrafluoroquinoxalino[2,3-b]phenazine-6,13-dione.

[0043] In this application, the flux is a compound containing an anhydride functional group, an amino functional group, or a carboxylic acid functional group, 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 this application, the melt polymerization reaction is preferably carried out under negative pressure in a closed, high-pressure resistant reaction vessel. The closed, high-pressure resistant reaction vessel can be a high-temperature and high-pressure resistant Pyrex tube, an ampoule requiring flame sealing, or a high-pressure reactor lined with polytetrafluoroethylene; preferably, the pressure of the melt polymerization reaction is ≤0.15 mmHg; the temperature of the melt polymerization reaction is 180~200℃, and the reaction time is 1~5 days.

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

[0046] In this application, the purification specifically involves washing the reaction product with DMF to remove unreacted monomers, then Soxhlet extracting it in methanol to remove flux, and finally drying it 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 by rationally improving the monomers. Specifically, in the synthesis of polyarylether-based covalent organic framework materials, when sodium benzene-1,3,5-triol is selected as organic monomer A, organic monomer B can be a halogen-substituent di-linked monomer or a halogen-substituent tri-linked monomer, such as any one of terephthalofluoride, terephthalodibromo, and terephthalodichloro. The general reaction formula is shown below:

[0048]

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

[0050] When organic monomer A is sodium benzene-1,3,5-triol, organic monomer B can also be a tri-linked monomer with halogen substituents, such as any one of 1,3,5-trichlorobenzene, 1,3,5-tribromobenzene, or cyanuric chloride. The general reaction formula is shown below:

[0051]

[0052] Where Y is Cl or Br;

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

[0054] 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 shown below:

[0059]

[0060] Compared with traditional solvothermal methods, this application's solvent-free solid-phase melt synthesis method avoids high-pressure operating conditions and the generation of large amounts of waste liquid during the reaction, simplifying the synthesis process of polyarylether-based COFs. It is safe, environmentally friendly, and suitable for large-scale production of polyarylether-based COFs. The polyarylether-based covalent porous organic framework materials prepared in this application have pore sizes of 0.5–3.8 nm, exhibiting high specific surface area, high porosity, and high mechanical strength.

[0061] The present application will be further illustrated by the following 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 and reacted for 4 hours. After the reaction was completed, the filtrate was collected by filtration, and the filtrate was evaporated to obtain a solid. The solid was dried under vacuum at 60 °C overnight to obtain sodium benzene-1,3,5-triol.

[0064] Example B: Preparation of sodium triphenyl-2,3,6,7,10,11-hexanediol

[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 thoroughly, and the mixture was heated to 90 °C and reacted for 4 hours. After the reaction was completed, the filtrate was collected by filtration, and the filtrate was evaporated to obtain a solid. The solid was dried under vacuum at 60 °C overnight to obtain sodium triphenyl-2,3,6,7,10,11-hexane.

[0066] Example 1

[0067] This embodiment provides a green solid-phase synthesis method for polyarylether-based covalent organic framework materials, including:

[0068] 0.1 mmol of sodium triphenyl-2,3,6,7,10,11-hexanediol, 0.15 mmol of 2,3,9,10-tetrafluoroquinoxalano[2,3-b]phenazine-6,13-dione, and 0.6 mmol of benzoic acid were weighed and placed into a high-temperature and high-pressure resistant thick-walled glass tube. The tube was evacuated to a pressure of 0.15 mmHg, and then sealed with a flame generated by an oxyhydrogen generator to isolate the internal and external systems. The sealed glass tube was placed in a 200°C oven for 5 days. After the reaction, a brownish-black blocky material was obtained. This material was soaked in DMF for 24 hours, then Soxhlet extracted in methanol for 10 hours, and finally dried at 100°C to obtain a brown powder material with a yield of approximately 89%, designated NKCOF-18.

[0069] Example 2

[0070] This embodiment provides a green solid-phase synthesis method for polyarylether-based covalent organic framework materials, including:

[0071] 0.1 mmol of sodium triphenyl-2,3,6,7,10,11-hexanediol, 0.15 mmol of 2,3,6,7-tetrafluoroanthracene-9,10-dione, and 0.6 mmol of benzoic acid were weighed and placed into a high-temperature and high-pressure resistant thick-walled glass tube. The tube was evacuated to a pressure of 0.15 mmHg, and then sealed with a flame generated by an oxyhydrogen generator to isolate the internal and external systems. The sealed glass tube was placed in a 200°C oven for 5 days. After the reaction, a brown blocky material was obtained. This material was soaked in DMF for 24 hours, then Soxhlet extracted in methanol for 10 hours, and finally dried at 100°C to obtain a brown powder material with a yield of approximately 91%, designated JUC-506.

[0072] Example 3

[0073] This embodiment provides a green solid-phase synthesis method for polyarylether-based covalent organic framework materials, including:

[0074] Weigh 0.1 mmol of sodium triphenyl-2,3,6,7,10,11-hexanediol, 0.15 mmol of 1,2,4,5-tetrafluorobenzene, and 0.6 mmol of benzoic acid, and place them into a high-temperature and high-pressure resistant thick-walled glass tube. Evacuate the tube to a pressure of 0.15 mmHg, and seal the tube with a flame generated by an oxyhydrogen generator to isolate the internal and external systems. Place the sealed glass tube in a 200°C oven and react for 5 days. After the reaction, a brownish-black blocky material is obtained. After soaking in DMF for 24 hours, it is extracted with methanol using a Soxhlet extracter for 10 hours, and then dried at 100°C to obtain a brownish-black powdery material with a yield of approximately 90%, denoted as NKCOF-19.

[0075] Example 4

[0076] This embodiment provides a green solid-phase synthesis method for polyarylether-based covalent organic framework materials, including:

[0077] Weigh 0.1 mmol of sodium benzene-1,3,5-triol, 0.15 mmol of 1,4-difluorobenzene, and 0.6 mmol of benzoic acid, and place them into a high-temperature and high-pressure resistant thick-walled glass tube. Evacuate the tube to a pressure of 0.15 mmHg, and seal the tube with a flame generated by an oxyhydrogen generator to isolate the internal and external systems. Place the sealed glass tube in an oven at 180°C and react for 5 days. After the reaction, a brownish-black blocky material is obtained. After soaking in DMF, it is extracted with methanol using a Soxhlet extractor for 10 h, and then dried at 100°C to obtain a brownish-black blocky material with a yield of approximately 85%, denoted as TBS-DFB-COF.

[0078] Example 5

[0079] This embodiment provides a green solid-phase synthesis method for polyarylether-based covalent organic framework materials, including:

[0080] Weigh 0.1 mmol of sodium benzene-1,3,5-triol, 0.15 mmol of 1,4-dichlorobenzene, and 0.6 mmol of benzoic acid, and place them into a high-temperature and high-pressure resistant thick-walled glass tube. Evacuate the tube to a pressure of 0.15 mmHg, and seal the tube with a flame generated by an oxyhydrogen generator to isolate the internal and external systems. Place the sealed glass tube in an oven at 180°C and react for 5 days. After the reaction, a brownish-black blocky material is obtained. After soaking in DMF, it is extracted with methanol using a Soxhlet extractor for 10 h, and then dried at 100°C to obtain a brownish-black blocky material with a yield of approximately 82%, denoted as TBS-DCB-COF.

[0081] Example 6

[0082] This embodiment provides a green solid-phase synthesis method for polyarylether-based covalent organic framework materials, including:

[0083] Weigh 0.1 mmol of sodium benzene-1,3,5-triol, 0.15 mmol of 1,4-dibromobenzene, and 0.6 mmol of benzoic acid, and place them into a high-temperature and high-pressure resistant thick-walled glass tube. Evacuate the tube to a pressure of 0.15 mmHg, and seal the tube with a flame generated by an oxyhydrogen generator to isolate the internal and external systems. Place the sealed glass tube in an oven at 180°C and react for 5 days. After the reaction, a brownish-black blocky material is obtained. After soaking in DMF, it is Soxhlet extracted in methanol for 10 h, and then dried at 100°C to obtain a brownish-black blocky material with a yield of approximately 84%, denoted as TBS-DBB-COF.

[0084] Example 7

[0085] This embodiment provides a green solid-phase synthesis method for polyarylether-based covalent organic framework materials, including:

[0086] Weigh 0.1 mmol of sodium benzene-1,3,5-triol, 0.1 mmol of cyanuric chloride, and 0.6 mmol of benzoic acid, and place them into a high-temperature and high-pressure resistant thick-walled glass tube. Evacuate the tube to a pressure of 0.15 mmHg, and seal the tube with a flame generated by an oxyhydrogen generator to isolate the internal and external systems. Place the sealed glass tube in an oven at 180°C and react for 5 days. After the reaction, a brownish-black blocky material is obtained. After soaking in DMF, it is Soxhlet extracted in methanol for 10 h, and then dried at 100°C to obtain a brownish-black blocky material with a yield of approximately 80%, denoted as TBS-TCT-COF.

[0087] Example 8

[0088] This embodiment provides a green solid-phase synthesis method for polyarylether-based covalent organic framework materials, including:

[0089] Weigh 0.1 mmol of sodium benzene-1,3,5-triol, 0.15 mmol of 1,3,5-trichlorobenzene, and 0.6 mmol of benzoic acid, and place them into a high-temperature and high-pressure resistant thick-walled glass tube. Evacuate the tube to a pressure of 0.15 mmHg, and seal the tube with a flame generated by an oxyhydrogen generator to isolate the internal and external systems. Place the sealed glass tube in an oven at 180°C and react for 5 days. After the reaction, a brownish-black blocky material is obtained. After soaking in DMF, it is extracted with methanol using a Soxhlet extractor for 10 h, and then dried at 100°C to obtain a brownish-black blocky material with a yield of approximately 85%, denoted as TBS-TCB-COF.

[0090] Example 9

[0091] This embodiment provides a green solid-phase synthesis method for polyarylether-based covalent organic framework materials, including:

[0092] 0.1 mmol of sodium benzene-1,3,5-triol, 0.1 mmol of 1,3,5-tribromobenzene, and 0.6 mmol of benzoic acid were weighed and placed into a high-temperature and high-pressure resistant thick-walled glass tube. The tube was evacuated to a pressure of 0.15 mmHg, and then sealed with a flame generated by an oxyhydrogen generator to isolate the internal and external systems. The sealed glass tube was placed in an oven at 180°C and reacted for 5 days. A brownish-black blocky material was obtained after the reaction. This material was soaked in DMF, then Soxhlet extracted in methanol for 10 h, and finally dried at 100°C to obtain a brownish-black blocky material with a yield of approximately 85%, denoted as TBS-TBB-COF.

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

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

[0095] 2. Infrared spectroscopy test, the results are as follows: Figure 2 As shown. Figure 2 Monmer-1 is sodium triphenyl-2,3,6,7,10,11-hexanediol, and monmer-2 is 2,3,9,10-tetrafluoroquinoxalano[2,3-b]phenazine-6,13-dione; Figure 2 It can be seen that NKCOF-18 is a COF material linked by ether bonds, of which 1631 cm⁻¹ -1 The peak corresponds to the stretching vibration of the carbon-oxygen single bond.

[0096] 3. The isothermal adsorption-desorption test of nitrogen at 77K yielded the following isothermal adsorption-desorption curve: Figure 3 As shown. From Figure 3 It can be seen that its BET surface area is 940 m². 2 / g, with a high specific surface area.

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

[0098] 5. Scanning electron microscopy (SEM) test, the test image is as follows: Figure 5 As shown. By Figure 5 It can be seen that the stacking of NKCOF-18 at the microscale is irregular, and the crystal particles are obvious.

[0099] 6. Thermogravimetric analysis, its thermogravimetric curve is as follows: Figure 6 As shown. By Figure 6 It is known that NKCOF-18 has excellent thermal stability, and it does not experience significant structural collapse before reaching 450℃.

[0100] The above demonstrates that this application simplifies the synthesis process of polyarylene ether-based COFs, achieving solvent-free and green synthesis of polyarylene ether-based COFs. The polyarylene ether-based covalent porous organic framework material prepared in this application possesses high specific surface area, high porosity, and high mechanical strength.

[0101] Although this application has been described in detail in this specification with general descriptions and specific embodiments, some modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, such modifications or improvements made without departing from the spirit of this application are all within the scope of protection claimed in this application.

Claims

1. A green solid-phase synthesis method for polyarylether-based covalent organic framework materials, characterized in that, include: Organic monomers A and B were melt-polymerized in the presence of a flux, and the reaction product was purified to obtain a polyarylether-based covalent organic framework material. The organic monomer A is sodium phenyl-1,3,5-triol or sodium triphenyl-2,3,6,7,10,11-hexanediol; The organic monomer B is a di-linked monomer, tri-linked monomer, or tetra-linked monomer containing halogen substituents. The flux is benzoic acid.

2. The green solid-phase synthesis method according to claim 1, characterized in that, The organic monomer B includes any one of terephthalofluoride, terephthalobromo, terephthalochloro, 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-tetrafluoroquinoxalino[2,3-b]phenazine-6,13-dione.

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

4. The green solid-phase synthesis method according to claim 3, characterized in that, The melt polymerization reaction is carried out in a sealed, high-pressure container with a pressure ≤0.15 mmHg.

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

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

1.

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

1.

8. The green solid-phase synthesis method according to claim 7, characterized in that, The molar ratio of the flux to organic monomer A is (6~8):1.

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