Imidazolium-based supercrosslinked ionic liquid polymer, and preparation method and application thereof

Abstract

The application belongs to the field of high polymer adsorbent synthesis, and relates to an imidazole-based supercrosslinked ionic liquid polymer and a preparation method and application thereof, steps comprising: mixing imidazole, 1,4-p-dibromobenzene, anhydrous potassium carbonate and copper sulfate pentahydrate, heating and reacting, extracting a product, and drying to obtain a precursor; adding the precursor and benzyl chloride into N,N-dimethylformamide to mix and dissolve, heating and reacting to obtain an ionic liquid monomer; adding benzyl alcohol, dimethoxymethane, anhydrous ferric chloride and the ionic liquid monomer into 1,2-dichloroethane, reacting at 40-60 DEG C for 4-8 h, and then increasing the temperature to 70-90 DEG C to react for 20-30 h to obtain a macromolecular polymer, which is washed and dried, impurities are removed, and grinding to obtain the imidazole-based supercrosslinked ionic liquid polymer. The application has simple process and low cost, and the prepared imidazole-based supercrosslinked ionic liquid polymer has large adsorption capacity and good adsorption effect on m-cresol or 2-bromophenol in water.

Description

Technical Field

[0001] This invention belongs to the field of polymer adsorbent synthesis, specifically relating to an imidazole-based hypercrosslinked ionic liquid polymer, its preparation method, and its application. Background Technology

[0002] m-Cresol and 2-bromophenol are intermediates or raw materials in many organic synthesis reactions. Even low concentrations of phenols exhibit significant toxicity, seriously threatening human health and causing substantial environmental damage. Their degradation and remediation technologies have long been a focus of research for scholars both domestically and internationally. Among various methods for removing phenolic compounds, adsorption has become a key research area due to its simple operation and mild reaction conditions. The adsorbent is crucial in adsorption methods; therefore, finding a green and stable adsorbent is a major challenge in the research of adsorption methods for removing phenolic compounds.

[0003] Ionic liquid polymers, as adsorbents, not only possess the high specific surface area of ​​porous materials but also the advantages of ionic liquids, such as low vapor pressure, high thermal stability, high chemical stability, and tunable molecular structure. Furthermore, macromolecular polymers can be reused multiple times. Ionic liquid polymers with nitrogen-containing groups such as imidazole groups exhibit excellent adsorption effects on phenolic compounds. Studies have shown that the introduction of nitrogen increases the active sites of the adsorbent. Additionally, by modifying the structure of the ionic liquid polymer, adsorption of different phenolic compounds can also be achieved. Based on this, this invention proposes a preparation method to obtain an imidazole-based hypercrosslinked ionic liquid polymer and its application in the field of phenolic compound adsorption. Summary of the Invention

[0004] The purpose of this invention is to solve the above-mentioned problems existing in the prior art, and to propose an imidazole-based hypercrosslinked ionic liquid polymer, its preparation method and application. An imidazole-based hypercrosslinked ionic liquid polymer with high specific surface area, large adsorption capacity and tunable molecular structure is prepared by a simple and low-cost process. It is applied to the field of phenolic compound adsorption and has a good adsorption effect on m-cresol or 2-bromophenol in water.

[0005] The technical solution of this invention is:

[0006] A method for preparing an imidazole-based hypercrosslinked ionic liquid polymer, characterized by comprising the following steps:

[0007] (1) Imidazole, 1,4-dibromobenzene, anhydrous potassium carbonate and copper sulfate pentahydrate were mixed in a molar ratio of 40:(8-12):(14-18):(0.08-0.12) and reacted at 130-150℃ for 20-30 h under an inert atmosphere. The reaction product was ground, washed, vacuum dried and then extracted. The resulting solution was rotary evaporated and vacuum dried to obtain the precursor.

[0008] The molar ratio of the imidazole to 1,4-dibromobenzene, anhydrous potassium carbonate, and copper sulfate pentahydrate is any value within the range of 40:(8-12):(14-18):(0.08-0.12), for example, it can be 40:10:16:0.1, 40:8:14:0.08, 40:12:18:0.12, 40:10:14:0.08, 40:8:14:0.12, or 40:10:18:0.12, or other ratios within the above range.

[0009] (2) Add the precursor and benzyl chloride in a molar ratio of (2.8-3.3):1 to N,N-dimethylformamide and mix and dissolve. Heat the mixture under an inert atmosphere and react at 65-75°C for 23-25 ​​h. Wash the reaction product and dry it under vacuum to obtain the ionic liquid monomer.

[0010] The molar ratio of the aforementioned precursor to benzyl chloride is any value within the range of (2.8 to 3.3):1, such as 3.1:1, 2.8:1, 2.9:1, 3.0:1, 3.2:1, or 3.31, etc.

[0011] (3) Add benzyl alcohol and dimethoxymethane to 1,2-dichloroethane, then add anhydrous ferric chloride and ionic liquid monomer dissolved in 1,2-dichloroethane. React at 40-60℃ for 4-8 hours under an inert atmosphere, then raise the temperature to 70-90℃ and react for 20-30 hours to obtain a macromolecular polymer. After centrifugation and washing, vacuum dry the precipitate to remove impurities, grind it, and obtain the imidazole-based hypercrosslinked ionic liquid polymer.

[0012] In step (3) above, anhydrous ferric chloride is first dissolved in 1,2-dichloroethane solvent and stirred to dissolve more ferric chloride in the solvent for later use; the ionic liquid monomer is dissolved in 1,2-dichloroethane solvent and stirred to form a homogeneous suspension for later use; finally, benzyl alcohol, dimethoxymethane, the prepared anhydrous ferric chloride, and the ionic liquid monomer are added to 1,2-dichloroethane for reaction.

[0013] Furthermore, in step (1), the molar ratio of imidazole, 1,4-dibromobenzene, anhydrous potassium carbonate and copper sulfate pentahydrate is 40:10:16:0.1.

[0014] Furthermore, in step (1), after the reaction product is ground, it is washed with distilled water 3 to 6 times until it is colorless, dried under vacuum at 70 to 90°C for 4 to 5 hours, extracted with dichloromethane 3 to 6 times, centrifuged to collect the supernatant, rotary evaporated the supernatant at 40 to 50°C, and dried under vacuum at 70 to 90°C for 12 to 24 hours to obtain a white solid. Grinding the white powder obtained is the precursor.

[0015] Furthermore, in step (2), the molar ratio of benzyl chloride to the precursor is 1:3.1.

[0016] Benzyl chloride and the precursor obtained in step (1) are added to N,N-dimethylformamide in a molar ratio and mixed and dissolved. The amount of N,N-dimethylformamide used needs to be sufficient to dissolve the added benzyl chloride and precursor. The ratio of N,N-dimethylformamide to precursor is approximately 10 mL: 1.90 mmol. Therefore, the ratio of N,N-dimethylformamide to benzyl chloride can be calculated to be approximately 10 mL: 5.89 mmol based on the molar ratio of benzyl chloride to precursor.

[0017] The vacuum drying conditions in step (2) above are: drying at 70-90℃ for 9-12 hours.

[0018] Furthermore, in step (3), the molar ratio of the ionic liquid monomer to benzyl alcohol and dimethoxymethane is (0.6-1):(1-6):(4-8);

[0019] The molar ratio of the ionic liquid monomer (IL) to benzyl alcohol and dimethoxymethane is any value within the range of (0.6-1):(1-6):(4-8). For example, it can be IL:benzyl alcohol:dimethoxymethane = 1:4:6, or it can be 1:3:4, 1:6:8, 0.6:1:4, 0.8:3:6, 0.6:6:8, 1:1:4, 1:3:6, etc.

[0020] The molar ratio of ferric chloride to benzyl alcohol is any value within the range of (1.2-6):(0.6-1), such as 1.2:0.6, 6:1, 4:0.8, 1.2:1, 6:0.6, 3:0.6, 3.6:0.8, 3.6:1, 5:1, 2:0.6, or 4:1, etc.;

[0021] The ratio of 1,2-dichloroethane to the ionic liquid monomer is any value within the range of 8 mL: (0.6 to 1) mol, for example, it can be 8 mL: 0.6 mol, 8 mL: 1 mol, 8 mL: 0.7 mol, 8 mL: 0.8 mol or 8 mL: 0.9 mol, etc.

[0022] Furthermore, in step (3), benzyl alcohol is replaced with aniline, and the molar ratio of the ionic liquid monomer to aniline and dimethoxymethane is (0.6-1):(1-6):(4-8).

[0023] Similarly, the molar ratio of the ionic liquid monomer to aniline and dimethoxymethane can be any value within the range of (0.6-1):(1-6):(4-8). For example, it can be IL:aniline:dimethoxymethane = 1:4:6, or it can be 1:3:4, 1:6:8, 0.6:1:4, 0.8:3:6, 0.6:6:8, 1:1:4, 1:3:6, etc.

[0024] In step (3) above, benzyl alcohol can be replaced by aniline, and the reaction steps, molar ratio, reaction temperature, reaction time and other reaction parameters remain unchanged.

[0025] Furthermore, in step (3), the obtained macromolecular polymer is first washed repeatedly by alternating centrifugation with distilled water and anhydrous ethanol at 6000-9000 r / min until colorless, the precipitate is collected, the precipitate is vacuum dried at 70-90℃ for 15-25 h, and then impurities are further removed by Soxhlet extraction. After vacuum drying at 60-80℃ for 40-50 h, it is ground, and the resulting brown solid powder is the imidazole-based hypercrosslinked ionic liquid polymer.

[0026] Furthermore, the inert atmosphere is a nitrogen atmosphere or an argon atmosphere.

[0027] This invention also protects an imidazole-based hypercrosslinked ionic liquid polymer, which is prepared by the preparation method described above.

[0028] This invention also protects the application of the imidazole-based hypercrosslinked ionic liquid polymer prepared by the above preparation method in the adsorption of phenolic compounds, wherein the application is for the adsorption of m-cresol or 2-bromophenol in water.

[0029] The preparation method provided by this invention utilizes the Friedel-Crafts alkylation reaction principle. The resulting imidazole-based hypercrosslinked ionic liquid polymer has a large specific surface area, is rich in nitrogen, and is extremely hydrophilic. Meanwhile, the m-cresol and 2-bromophenol to be adsorbed possess hydroxyl groups and are hydrophilic. Therefore, this imidazole-based hypercrosslinked ionic liquid polymer exhibits a strong adsorption capacity for m-cresol or 2-bromophenol. Furthermore, this imidazole-based hypercrosslinked ionic liquid polymer can be recycled multiple times (the adsorption effect remains at an ideal level even after five adsorption-desorption cycles).

[0030] The beneficial effects of this invention are:

[0031] (1) The preparation method provided by the present invention has simple process steps and low cost. The synthesized imidazole-based hypercrosslinked ionic liquid polymer has an ideal and large specific surface area and layered pore structure. It has a large adsorption capacity for m-cresol and 2-bromophenol. Furthermore, the eluent is anhydrous ethanol, which is green and environmentally friendly and can quickly reach adsorption saturation. The imidazole-based hypercrosslinked ionic liquid polymer of the present invention can be reused multiple times as an adsorbent.

[0032] (2) This invention regulates the specific surface area and pore structure of the prepared imidazole-based hypercrosslinked ionic liquid polymer by changing the prepolymerization time and the ratio of ionic liquid to crosslinking agent and co-crosslinking agent. The large number of benzene rings also increases the active sites of the adsorbent, resulting in different adsorption effects on m-cresol or 2-bromophenol. Furthermore, the synthesis steps are simple, the raw materials are inexpensive, and it has good application prospects. Attached Figure Description

[0033] Figure 1 The 1H NMR spectrum of the ionic liquid monomer obtained in Example 1;

[0034] Figure 2 FI-TR images of imidazole-based hypercrosslinked ionic liquid polymers with different prepolymerization times prepared in Examples 1-4;

[0035] Figure 3 SEM images of PIL-Ba-5 (IL: benzyl alcohol: dimethoxymethane = 1:4:6) and PIL-An-5 (IL: aniline: dimethoxymethane = 1:4:6); where (a) is the SEM image of PIL-An-5 and (b) is the SEM image of PIL-Ba-5. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] To further understand the present invention, it will be further described in conjunction with the accompanying drawings and embodiments.

[0038] Example 1

[0039] This embodiment provides a method for preparing an imidazole-based hypercrosslinked ionic liquid polymer, comprising the following steps:

[0040] (1) Mix 3g (40mmol) imidazole, 2.36g (10mmol) 1,4-p-dibromobenzene, 2.21g (16mmol) potassium carbonate and 0.025g (0.1mmol) copper sulfate, and heat the mixture in a high-pressure reactor under a nitrogen atmosphere at 150℃ for 24h. Grind the obtained solid product, wash it with distilled water until it is colorless, dry it under vacuum at 80℃ for 4h, extract it four times with dichloromethane, and collect the supernatant by centrifugation. Rotary evaporate the supernatant at 45℃, and then dry it in a vacuum drying oven at 80℃ for 20h to obtain a white solid. Grind the solid to obtain a white powder, which is the precursor.

[0041] (2) Dissolve 0.4 g (1.90 mmol) of the precursor obtained in step (1) in 10 mL of N,N-dimethylformamide, add 0.745 g of benzyl chloride, stir and mix, and heat to 70 °C for 24 h under nitrogen atmosphere. Wash the reaction product three times with ethyl acetate, and then dry it in a vacuum drying oven at 80 °C for 10 h to obtain a white solid, which is the ionic liquid monomer.

[0042] like Figure 1 The image shows the proton NMR spectrum of the ionic liquid monomer.

[0043] (3) Dissolve 1.023 g of anhydrous ferric chloride in 10 mL of 1,2-dichloroethane and set aside. Then dissolve 0.486 g of the ionic liquid monomer synthesized in step (2) in 8 mL of 1,2-dichloroethane, add 0.478 g of dimethoxymethane and 0.453 g of benzyl alcohol, and finally add the anhydrous ferric chloride dissolved in 1,2-dichloroethane. Let it react in a nitrogen atmosphere, first at 50 °C for 4 h, and then at 80 °C for 24 h. The synthesized macromolecular polymer was first washed with distilled water until colorless, then with anhydrous ethanol until colorless. It was then centrifuged at 7000 r / min to remove distilled water and anhydrous ethanol, and the solid was collected. It was dried in a vacuum drying oven at 80℃ for 12 h. The solid was then extracted with a Soxhlet extract of 40 mL of anhydrous ethanol and 20 mL of distilled water, and then dried under vacuum at 70℃ for 48 h before grinding to obtain a brown solid powder, which is the imidazole-based hypercrosslinked ionic liquid polymer PIL-Ba-4.

[0044] The imidazole-based hypercrosslinked ionic liquid polymer synthesized using benzyl alcohol is used to adsorb m-cresol or 2-bromophenol from water.

[0045] Example 2

[0046] Benzyl alcohol was used in the same manner as in Example 1, with a molar ratio of 1L:benzyl alcohol:dimethoxymethane = 1:4:6;

[0047] The difference from Example 1 is that the prepolymerization time in step (3) is 5h, that is, the reaction is first carried out at 50°C for 5h, and then the temperature is raised to 80°C for 24h.

[0048] The prepared imidazole-based hypercrosslinked ionic liquid polymer PIL-Ba-5 was used to adsorb m-cresol or 2-bromophenol from water.

[0049] Example 3

[0050] Benzyl alcohol was used in the same manner as in Example 1, with a molar ratio of 1L:benzyl alcohol:dimethoxymethane = 1:4:6;

[0051] The difference from Example 1 is that the prepolymerization time in step (3) is 6 hours, that is, the reaction is first carried out at 50°C for 5 hours, and then the temperature is raised to 80°C for 24 hours.

[0052] The prepared imidazole-based hypercrosslinked ionic liquid polymer PIL-Ba-6 was used to adsorb m-cresol or 2-bromophenol from water.

[0053] Example 4

[0054] Benzyl alcohol was used in the same manner as in Example 1, with a molar ratio of 1L:benzyl alcohol:dimethoxymethane = 1:4:6;

[0055] The difference from Example 1 is that the prepolymerization time in step (3) is 7h, that is, the reaction is first carried out at 50°C for 5h, and then the temperature is raised to 80°C for 24h.

[0056] The prepared imidazole-based hypercrosslinked ionic liquid polymer PIL-Ba-7 was used to adsorb m-cresol or 2-bromophenol from water.

[0057] Example 5

[0058] The difference from Example 2 is that aniline is used instead of benzyl alcohol. The amounts of each raw material added were calculated using a molar ratio of IL:aniline:dimethoxymethane = 1:4:6 as follows: anhydrous ferric chloride 1.059 g, ionic liquid monomer 0.503 g, aniline 0.404 g, and dimethoxymethane 0.496 g.

[0059] Everything else was the same as in Example 2; the imidazole-based hypercrosslinked ionic liquid polymer PIL-An-5 was prepared.

[0060] Experimental Example 1

[0061] The imidazole-based hypercrosslinked ionic liquid polymers synthesized in Examples 1-4 were characterized by FI-TR to demonstrate the successful polymerization of the imidazole-based hypercrosslinked ionic liquid polymers synthesized from benzyl alcohol. The FI-TR values ​​of the four polymers with different prepolymerization times (PIL-Ba-4, PIL-Ba-5, PIL-Ba-6, PIL-Ba-7) are shown below. Figure 2 As shown.

[0062] Experimental Example 2

[0063] m-Cresol was used in adsorption experiments to verify the adsorption effect of the adsorbents prepared in Examples 1-5 of this invention. A 100 ppm m-cresol solution was used as the adsorbate, with 25 mL of each solution and 0.085 g of each adsorbent, and adsorption was performed at 25°C. The adsorption rates of m-cresol by the imidazole-based hypercrosslinked ionic liquid polymers prepared with different prepolymerization times are shown in Table 1.

[0064] Table 1. Adsorption rate data of m-cresol by imidazole-based hypercrosslinked ionic liquid polymers in Examples 1-5.

[0065] PIL-Ba-4 0.1g, 25mL, 25℃, 4h 21.69 mg / g PIL-Ba-5 0.085g, 25mL, 25℃, 4h 28.34 mg / g PIL-Ba-6 0.085g, 25mL, 25℃, 4h 26.25mg / g PIL-Ba-7 0.1g, 25mL, 25℃, 4h 22.51 mg / g PIL-An-5 0.085g, 25mL, 25℃, 4h 17.62 mg / g

[0066] The data in the table show that PIL-Ba-5 exhibits the best adsorption effect for m-cresol. Furthermore, during the adsorption process, PIL-Ba-5 achieved an adsorption rate of 96% and an adsorption capacity of 28.34 mg / g in approximately 6 minutes. The table also demonstrates the important role of benzyl alcohol in the adsorption. Changing the prepolymerization time also significantly affects the adsorption efficiency of the adsorbent.

[0067] Electron microscopy was performed on polymers PIL-Ba-5 and PIL-An-5 from Examples 2 and 5, respectively, and the results were as follows: Figure 3 The SEM images shown indicate that PIL-An-5 is a bulk solid with no obvious porous structure at a size of 500 nm, while PIL-Ba-5 exhibits a nanoparticle aggregate structure with obvious pore morphology. This provides a large specific surface area and active sites for the adsorption of m-cresol, which is beneficial for adsorption.

[0068] Example 6

[0069] The difference from Example 1 is that the molar ratio of ionic liquid monomer: benzyl alcohol: dimethoxymethane in step (3) is 1:3:4, and the prepolymerization time is 5h;

[0070] The specific differences are as follows:

[0071] (3) Dissolve 0.770 g of anhydrous ferric chloride in 10 mL of 1,2-dichloroethane, then dissolve 0.549 g of the ionic liquid monomer synthesized in step (2) in 8 mL of 1,2-dichloroethane, add 0.361 g of dimethoxymethane and 0.384 g of benzyl alcohol, and finally add the anhydrous ferric chloride that was initially dissolved in 1,2-dichloroethane. Let it react in a nitrogen atmosphere, first at 50 °C for 5 h, then at 80 °C for 24 h.

[0072] The remaining steps are the same as in Example 1. The resulting imidazole-based hypercrosslinked ionic liquid polymer is used to adsorb m-cresol or 2-bromophenol from water.

[0073] Example 7

[0074] The difference from Example 1 is that the molar ratio of ionic liquid monomer: benzyl alcohol: dimethoxymethane in step (3) is 1:6:8, and the prepolymerization time is 5h;

[0075] The specific differences are as follows:

[0076] (3) Dissolve 1.062 g of anhydrous ferric chloride in 10 mL of 1,2-dichloroethane, then dissolve 0.378 g of the ionic liquid monomer synthesized in step (2) in 8 mL of 1,2-dichloroethane, add 0.497 g of dimethoxymethane and 0.530 g of benzyl alcohol, and finally add the anhydrous ferric chloride that was initially dissolved in 1,2-dichloroethane. Let it react in a nitrogen atmosphere, first at 50 °C for 5 h, then at 80 °C for 24 h.

[0077] The remaining steps are the same as in Example 1. The resulting imidazole-based hypercrosslinked ionic liquid polymer is used to adsorb m-cresol or 2-bromophenol from water.

[0078] Example 8

[0079] The difference from Example 1 is that the molar ratio of ionic liquid monomer: benzyl alcohol: dimethoxymethane in step (3) is 0.6:1:4, and the prepolymerization time is 5h;

[0080] The specific differences are as follows:

[0081] (3) Dissolve 0.441 g of anhydrous ferric chloride in 10 mL of 1,2-dichloroethane, then dissolve 0.629 g of the ionic liquid monomer synthesized in step (2) in 8 mL of 1,2-dichloroethane, add 0.688 g of dimethoxymethane and 0.245 g of benzyl alcohol, and finally add the anhydrous ferric chloride that was initially dissolved in 1,2-dichloroethane. Let it react in a nitrogen atmosphere, first at 50 °C for 5 h, then at 80 °C for 24 h.

[0082] The remaining steps are the same as in Example 1. The resulting imidazole-based hypercrosslinked ionic liquid polymer is used to adsorb m-cresol or 2-bromophenol from water.

[0083] Experimental Example 3

[0084] 2-Bromophenol was used in adsorption experiments to verify the adsorption effect of the adsorbents prepared in Examples 6-8 of this invention. A 100 ppm 2-bromophenol solution was used as the adsorbate; 25 mL of the solution was used, and 0.05 g of the adsorbent was added. Adsorption was carried out at 25°C. The adsorption rates are shown in Table 2.

[0085] Table 2 shows the adsorption rates of PIL-Ba-5 for 2-bromophenol obtained in Examples 6-8 and Example 1.

[0086]

[0087] As shown in the table, the adsorbent with an IL:benzyl alcohol:dimethoxymethane ratio of 1:6:8 exhibits the highest adsorption rate and adsorption capacity for 2-bromophenol, at 100% and 50.347 mg / g, respectively. Furthermore, the adsorbent reaches adsorption equilibrium for 2-bromophenol in approximately 6 minutes.

[0088] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, alterations, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing an imidazole-based hypercrosslinked ionic liquid polymer, characterized in that, Includes the following steps: (1) Imidazole, 1,4-dibromobenzene, anhydrous potassium carbonate and copper sulfate pentahydrate were mixed in a molar ratio of 40:(8-12):(14-18):(0.08-0.12) and reacted at 130-150℃ for 20-30 h under an inert atmosphere. The reaction product was ground, washed, vacuum dried and then extracted. The resulting solution was rotary evaporated and vacuum dried to obtain the precursor. (2) Add the precursor and benzyl chloride in a molar ratio of (2.8-3.3):1 to N,N-dimethylformamide and mix and dissolve. Heat the mixture under an inert atmosphere and react at 65-75°C for 23-25 ​​h. Wash the reaction product and dry it under vacuum to obtain the ionic liquid monomer. (3) Add benzyl alcohol and dimethoxymethane to 1,2-dichloroethane, then add anhydrous ferric chloride and ionic liquid monomer dissolved in 1,2-dichloroethane. React at 40-60℃ for 4-8 hours under an inert atmosphere, then raise the temperature to 70-90℃ and react for 20-30 hours to obtain a macromolecular polymer. After centrifugation and washing, vacuum dry the precipitate to remove impurities, grind it, and obtain the imidazole-based hypercrosslinked ionic liquid polymer.

2. The preparation method according to claim 1, characterized in that, In step (1), the molar ratio of imidazole, 1,4-p-dibromobenzene, anhydrous potassium carbonate and copper sulfate pentahydrate is 40:10:16:0.

1.

3. The preparation method according to claim 1, characterized in that, In step (1), after the reaction product is ground, it is washed with distilled water 3 to 6 times until it is colorless, dried under vacuum at 70 to 90°C for 4 to 5 hours, extracted with dichloromethane 3 to 6 times, centrifuged to collect the supernatant, rotary evaporated the supernatant at 40 to 50°C, and dried under vacuum at 70 to 90°C for 12 to 24 hours to obtain a white solid. Grinding the solid yields a white powder, which is the precursor.

4. The preparation method according to claim 1, characterized in that, In step (2), the molar ratio of benzyl chloride to the precursor is 1:3.

1.

5. The preparation method according to claim 1, characterized in that, The molar ratio of the ionic liquid monomer to benzyl alcohol and dimethoxymethane in step (3) is (0.6-1):(1-6):(4-8); The molar ratio of ferric chloride to benzyl alcohol is (1.2–6):(0.6–1); The ratio of 1,2-dichloroethane to the ionic liquid monomer is 8 mL: (0.6–1) mol.

6. The preparation method according to claim 1, characterized in that, In step (3), benzyl alcohol is replaced with aniline, and the molar ratio of the ionic liquid monomer to aniline and dimethoxymethane is (0.6-1):(1-6):(4-8).

7. The preparation method according to claim 1, characterized in that, In step (3), the obtained macromolecular polymer is first washed repeatedly by alternating centrifugation with distilled water and anhydrous ethanol at 6000-9000 r / min until it is colorless. The precipitate is collected and vacuum dried at 70-90℃ for 15-25 h. Then, Soxhlet extraction is used to further remove impurities. After drying, it is ground and the resulting brown solid powder is the imidazole-based hypercrosslinked ionic liquid polymer.

8. The preparation method according to claim 1, characterized in that, The inert atmosphere is a nitrogen atmosphere or an argon atmosphere.

9. An imidazole-based hypercrosslinked ionic liquid polymer, characterized in that, The imidazole-based hypercrosslinked ionic liquid polymer is prepared according to any one of claims 1-8.

10. The application of the imidazole-based hypercrosslinked ionic liquid polymer prepared by the preparation method according to any one of claims 1-8 in the adsorption of phenolic compounds, characterized in that, The application is for adsorbing m-cresol or 2-bromophenol in water.

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