A macroporous adsorption resin and its preparation method

Abstract

The present invention discloses a macroporous adsorption resin and a preparation method thereof, belonging to the technical fields of chemical engineering and medicine. The preparation method of the macroporous adsorption resin is to mix divinylbenzene, methyl methacrylate, an initiator and a solvent to form an oil phase, and mix water, a modified functional agent, gelatin and methylene blue to form an aqueous phase. Through a polymerization reaction under controlled temperature, followed by filtration, water washing, extraction with toluene and methanol, and a final water washing step, the macroporous adsorption resin is obtained. Compared with the prior art, the preparation method of the present invention can significantly improve the specific surface area and mechanical strength of the resin, and enhance its adsorption performance and durability.

Description

Technical Field

[0001] The present invention relates to the technical fields of chemical engineering and medicine, and particularly to a macroporous adsorption resin and a preparation method thereof. Background Art

[0002] With the acceleration of the industrialization process, the demand for efficient and environmentally friendly separation and purification technologies in the chemical and pharmaceutical industries is increasing day by day. In this context, macroporous adsorption resins, as an important separation material, show extensive application potential in the separation, purification, and extraction of liquids and gases due to their unique pore structure and adjustable surface chemical properties. Traditional macroporous adsorption resins are usually prepared by relying on organic solvents and toxic initiators, which not only cause environmental pollution but also may affect the health of operators.

[0003] Moreover, in the fields of chemical engineering and medicine, macroporous adsorption resins are widely used for the separation and purification of substances due to their unique pore structure. However, the macroporous adsorption resins prepared by the existing technologies usually face the problems of insufficient specific surface area and low mechanical strength, which limit their adsorption efficiency and durability. Especially in the separation processes that require high efficiency, the low specific surface area of the resin results in limited adsorption sites, while the insufficient strength makes the resin prone to breakage during repeated use or under high pressure, affecting the stability and reliability of its long-term industrial application.

[0004] Chinese Patent CN112029028A discloses a macroporous adsorption resin for extracting vitamin B12 and a preparation method thereof. Tap water, gelatin or polyvinyl alcohol, and methylene blue are mixed and stirred to dissolve to form an aqueous phase; monomers, initiators, and pore-forming agents are mixed and stirred until completely dissolved to obtain an oil phase; the prepared oil phase is added to the prepared aqueous phase. After the oil phase and the aqueous phase are completely separated, the rotation speed is adjusted to control the particle size, and then the temperature is raised and kept constant; after the reaction is completed, the resin is put into a steam extractor for extraction, the pore-forming agent is recovered, and the resin with a particle size of 0.315 - 1.25 mm is screened as the finished product of the macroporous adsorption resin. This invention adopts the suspension polymerization method, which can realize the green and environmentally friendly production of macroporous adsorption resins and also can achieve the efficient extraction of vitamin B12. However, the specific surface area and strength of the macroporous adsorption resin prepared by this invention are insufficient, and the adsorption effect and durability are poor. Summary of the Invention

[0005] Aiming at the limitations in the prior art, the present invention aims to develop a new type of macroporous adsorption resin and a preparation method thereof to solve the problems of insufficient adsorption performance and poor environmental friendliness existing in the prior art.

[0006] To achieve the above-mentioned invention purpose, the present invention adopts the following technical solutions:

[0007] A preparation method of a macroporous adsorption resin is as follows:

[0008] Mix divinylbenzene, methyl methacrylate, initiator and solvent to form an oil phase, and mix water, modified functional agent, gelatin and methylene blue to form an aqueous phase. Then, carry out a polymerization reaction on the oil and water phases under controlled temperature. Subsequently, remove impurities and solvents through filtration, water washing, extraction with toluene and methanol, and a final water washing step, and perform screening and packaging to obtain macroporous adsorption resin.

[0009] The preparation method of the modified functional agent is as follows:

[0010] S1. First, add lignin to water, and add a pH basic regulator under stirring conditions to adjust the pH value. After continuous stirring, let the mixture stand, then separate the precipitate by suction filtration, add a pH acidic regulator to the filtrate to adjust the pH value, and let it stand again. After suction filtration, water washing and drying, a pretreated product is obtained;

[0011] S2. Add the pretreated product prepared in step S1 to dimethyl sulfoxide and heat it in an oil bath. At this temperature, add 1-formyl-piperidine-4-carbonyl chloride and stir continuously. Then, pour the mixture into isopropanol to terminate the reaction, separate the sediment by centrifugation, and obtain a post-treated product by vacuum drying;

[0012] S3. Add the post-treated product prepared in step S2 to N-methylpyrrolidone, and add phosphoric acid and triphenylphosphine, and carry out treatment at a high temperature. Then, remove the solvent by vacuum distillation, and remove N-methylpyrrolidone and phosphoric acid by pressure evaporation. Next, carry out extraction with ethyl acetate and methanol, and wash with water until neutral, and obtain the modified functional agent by drying.

[0013] Furthermore, a preparation method of macroporous adsorption resin is as follows, in parts by weight:

[0014] (1) Preparation and stirring:

[0015] Mix 200 - 400 parts of divinylbenzene, 20 - 30 parts of methyl methacrylate, and 250 - 330 parts of solvent in an oil phase container, add 3 - 4 parts of initiator, and stir for 0.3 - 0.8 hours to obtain an oil phase; in another container, heat 800 - 900 parts of water to 70 - 90 °C, add 20 - 40 parts of modified functional agent, 20 - 30 parts of gelatin, and 0.005 - 0.02 parts of methylene blue, and stir until uniform to obtain an aqueous phase;

[0016] (2) Polymerization reaction:

[0017] Mix the oil phase prepared in step (1) and the water phase prepared in step (1), control the temperature at 70-90 °C until the gel point appears, then keep warm for 2-3 hours, then raise the temperature to 80-95 °C and keep warm for 4-8 hours, and finally raise the temperature to 90-98 °C and keep warm for 2-4 hours;

[0018] (3) Filtration:

[0019] After the polymerization reaction is completed, cool down to below 60-80 °C, and use a filtration device to separate the adsorption resin and the reaction wastewater;

[0020] (4) Water washing:

[0021] Wash the adsorption resin 1-3 times with 800-1200 parts of water each time, stir for 20-40 minutes each time, and the wet material after the last water wash enters the toluene extraction kettle;

[0022] (5) Toluene extraction:

[0023] Wash the adsorption resin with 3000-4000 parts of toluene at 60-80 °C until the gasoline and impurity residues are less than 80-120 ppm, and then recover the toluene;

[0024] (6) Methanol extraction:

[0025] Transfer the material to the methanol extraction kettle, wash the adsorption resin with 9000-10000 parts of methanol at 50-60 °C until the toluene residue is less than 80-120 ppm, and then recover the methanol;

[0026] (7) Water washing:

[0027] Transfer the adsorption resin to the water washing kettle, heat the water to 50-70 °C for washing, with a water consumption of 800-1200 parts, and continue for 20-40 minutes;

[0028] (8) Screening and packaging:

[0029] Screen the adsorption resin after water washing, and package it according to different particle size requirements to obtain the macroporous adsorption resin.

[0030] The solvent is at least one of gasoline and liquid paraffin.

[0031] The initiator is azobisisobutyronitrile.

[0032] Preferably, the preparation method of the modified functional agent is as follows, in parts by weight:

[0033] S1. First, add 15 - 25 parts of lignin into 180 - 220 parts of water, and add a pH basic regulator under stirring conditions to adjust the pH value to 9 - 11. After continuously stirring for 0.5 - 2 hours, let the mixture stand for 3 - 5 hours. Then, separate the precipitate by suction filtration, add a pH acidic regulator to the filtrate to adjust the pH value to 3 - 5, and let it stand for 8 - 15 hours again. After suction filtration, washing with water and drying, a pretreated product is obtained;

[0034] S2. Add the pretreated product prepared in step S1 into 180 - 220 parts of dimethyl sulfoxide, and heat it to 90 - 110 °C in an oil bath. At this temperature, add 80 - 120 parts of 1 - formyl - piperidine - 4 - carbonyl chloride and continuously stir for 3 - 5 hours. Then, quickly pour the mixture into 400 - 600 parts of isopropanol to terminate the reaction. Separate the sediment by centrifugation and obtain a post - treated product by vacuum drying;

[0035] S3. Add the post - treated product prepared in step S2 into 180 - 220 parts of N - methylpyrrolidone, and add 2 - 4 parts of phosphoric acid and 0.4 - 0.6 parts of triphenylphosphine. Treat at 80 - 120 °C for 5 - 10 hours. Then, remove the solvent by vacuum distillation, and remove N - methylpyrrolidone and phosphoric acid by pressure evaporation. Next, extract with ethyl acetate and methanol, and wash with water until neutral. After drying, a modified functional agent is obtained.

[0036] Further preferably, the preparation method of the modified functional agent is as follows, by weight:

[0037] S1. First, add 15 - 25 parts of lignin into 180 - 220 parts of water, and add a pH basic regulator under stirring conditions to adjust the pH value to 9 - 11. After continuously stirring for 0.5 - 2 hours, let the mixture stand for 3 - 5 hours. Then, separate the precipitate by suction filtration, add a pH acidic regulator to the filtrate to adjust the pH value to 3 - 5, and let it stand for 8 - 15 hours again. After suction filtration, washing with water and drying, a pretreated product is obtained;

[0038] S2. Add the pretreated product prepared in step S1 into 180 - 220 parts of dimethyl sulfoxide, and heat it to 90 - 110 °C in an oil bath. At this temperature, add 40 - 60 parts of 1 - formyl - piperidine - 4 - carbonyl chloride and 40 - 60 parts of (9ci) - 4 - amino - cyclohexanecarbonyl chloride and continuously stir for 3 - 5 hours. Then, quickly pour the mixture into 400 - 600 parts of isopropanol to terminate the reaction. Separate the sediment by centrifugation and obtain a post - treated product by vacuum drying;

[0039] S3. Add the post-treated product prepared in step S2 into 180 - 220 parts of N-methylpyrrolidone, add 2 - 4 parts of phosphoric acid and 0.4 - 0.6 parts of triphenylphosphine, conduct treatment at 80 - 120 °C for 5 - 10 hours, then remove the solvent by vacuum distillation, and remove N-methylpyrrolidone and phosphoric acid by pressure evaporation. Then, conduct extraction using ethyl acetate and methanol, and wash with water until neutral. After drying, a modified functional agent is obtained.

[0040] The pH basic regulator is a 0.4 - 0.6 mol / L aqueous sodium hydroxide solution.

[0041] The pH acidic regulator is 0.4 - 0.6 mol / L hydrochloric acid.

[0042] The centrifugation speed for centrifugally separating the sediment is 8000 - 12000 rpm.

[0043] The functions of each substance in the present invention are as follows:

[0044] Divinylbenzene, as one of the main monomers of the oil phase, participates in the polymerization reaction to form the framework structure of the macroporous adsorption resin.

[0045] Methyl methacrylate, as another monomer of the oil phase, copolymerizes with divinylbenzene to adjust the physical and chemical properties of the resin, such as toughness and reactivity.

[0046] The initiator (azobisisobutyronitrile) initiates the polymerization reaction, causing monomers such as divinylbenzene and methyl methacrylate to start polymerizing to form the resin.

[0047] The solvents (gasoline, liquid paraffin) are used for the preparation of the oil phase, helping to dissolve the monomers and the initiator, and ensuring the uniform progress of the polymerization reaction.

[0048] The modified functional agent is prepared from lignin through a series of chemical reactions, and is used to improve the performance of the resin, enhancing its adsorption capacity and mechanical strength.

[0049] Gelatin, as a part of the water phase, helps to form a stable emulsion system and plays a stabilizing role in the polymerization reaction.

[0050] Methylene blue, as a part of the water phase, may be used to indicate the progress of the polymerization reaction or as a pH indicator.

[0051] Sodium hydroxide, as a pH basic regulator, is used to adjust the pH value of the lignin solution to make it more suitable for subsequent chemical reactions.

[0052] Hydrochloric acid, as a pH acidic regulator, is used to adjust the pH value of the lignin solution.

[0053] In the present invention, lignin is subjected to phenolic modification to selectively cleave the methoxy ether bonds in lignin to generate phenolic hydroxyl groups while retaining sulfonic acid groups, thereby obtaining phenolic lignin. This modified lignin not only improves the chemical reactivity but also enhances its compatibility with resin-based materials, enabling the prepared macroporous adsorption resin to have a higher specific surface area and better mechanical strength, and further enhancing the adsorption performance and application scope of the resin.

[0054] Dimethyl sulfoxide is used as an organic solvent to assist in the treatment of pretreated lignin for the next chemical reaction.

[0055] 1-Formyl-piperidine-4-carbonyl chloride is used in the modification reaction of lignin to introduce a carbonyl group and a piperidine ring structure, enhancing the reactivity of lignin and the crosslinking density of the resin.

[0056] Phosphoric acid promotes the selective cleavage of methoxy ether bonds in lignin in the present invention to generate more phenolic hydroxyl groups, thereby improving the reactivity of the modified functional agent and the crosslinking density of the resin.

[0057] Isopropanol is used to terminate the reaction, and then the modified lignin is separated by precipitation.

[0058] N-Methylpyrrolidone is used as a solvent to assist in the treatment of the modified lignin for the next chemical reaction.

[0059] Triphenylphosphine is used as a catalyst to promote the chemical reaction of the modified functional agent and improve the reaction efficiency.

[0060] Ethyl acetate and methanol are used for the extraction and purification of the modified functional agent to remove excess reactants and by-products.

[0061] Toluene and methanol are used in the washing and extraction steps to remove impurities and solvents in the resin and recover the available solvents.

[0062] These substances play a key role in the preparation process of the macroporous adsorption resin. From the initiation and progress of the polymerization reaction to the modification, purification, and final shaping of the resin, the specific functions of these substances are indispensable at each step.

[0063] Compared with the prior art, it has the following beneficial effects:

[0064] 1) By finely regulating the preparation process of the macroporous adsorption resin, especially by introducing a modified functional agent, the present invention successfully improves the specific surface area of the resin. This structural optimization enables the resin to have more active sites, thereby enhancing its adsorption performance, especially its adsorption ability for specific molecules.

[0065] 2) By introducing a modified functional agent and optimizing the polymerization conditions, the macroporous adsorption resin prepared in the present invention exhibits higher mechanical strength. This enhanced mechanical property enables the resin to have a longer service life and better stability in various application scenarios, especially in environments subjected to pressure and abrasion.

[0066] 3) The preparation method adopted in the present invention reduces the use of harmful chemical substances. For example, phosphoric acid is used as a catalyst to replace the more corrosive hydrofluoric acid and hydrobromic acid. In addition, more environmentally friendly raw materials and steps are employed in the preparation process of the modifier, making the entire production process more environmentally friendly. Detailed implementation mode

[0067] Main sources of substances:

[0068] Liquid paraffin, grade: 300#, melting point: 120 (°C), oil content: 99.9 (%), Guangzhou Jinquan Chemical Co., Ltd.

[0069] Gelatin, product number: G108397, Shanghai Aladdin Biochemical Technology Co., Ltd., specification or purity: photographic grade, gel strength ~250g Bloom.

[0070] Lignin, Shanghai Macklin Biochemical Co., Ltd., product number L849279.

[0071] Phosphoric acid, product number: P816337, reagent grade, ≥85wt% in H 2 O, purchased from Shanghai Macklin Biochemical Co., Ltd.

[0072] Hydrofluoric acid, concentration 40wt%.

[0073] Hydrobromic acid, concentration 48wt%.

[0074] 1-Formyl-piperidine-4-carbonyl chloride, CAS number: 84163-43-9.

[0075] (9ci)-4-Amino-cyclohexanecarbonyl chloride, CAS number: 763036-24-4.

[0076] The remaining raw materials in the examples and comparative examples of the present invention are all commercially available products.

[0077] The design concept of the present invention is to finely regulate the preparation process of macroporous adsorption resin, including the innovative preparation method of modified functional agents and suspension polymerization technology, so as to increase the specific surface area and mechanical strength of the adsorption resin, thereby enhancing its adsorption performance and durability. Specifically, by introducing acyl chloride compounds such as 1-formyl-piperidine-4-carbonyl chloride with specific structures as modifiers and optimizing the conditions of the polymerization reaction, effective regulation of the pore structure and surface characteristics of the resin is achieved, and then macroporous adsorption resin with better performance is prepared.

[0078] Example 1

[0079] A preparation method of macroporous adsorption resin is as follows:

[0080] (1) Material preparation and stirring:

[0081] Mix 300 g of divinylbenzene, 27 g of methyl methacrylate, 225 g of gasoline and 75 g of liquid paraffin in an oil-phase container, add 3.4 g of azobisisobutyronitrile, and stir for 0.5 hour to obtain an oil phase; in another container, heat 856 g of water to 80 °C, add 25 g of gelatin and 0.01 g of methylene blue, and stir until uniform to obtain an aqueous phase;

[0082] (2) Polymerization reaction:

[0083] Mix the oil phase prepared in step (1) and the aqueous phase prepared in step (1), control the temperature at 80 °C until the gel point appears and then continue to keep warm for 2.5 hours, then raise the temperature to 90 °C and keep warm for 6 hours, and finally raise the temperature to 95 °C and keep warm for 3 hours;

[0084] (3) Filtration:

[0085] After the polymerization reaction is completed, cool down to below 70 °C, and use a filtration device to separate the adsorption resin and the reaction wastewater;

[0086] (4) Water washing:

[0087] Wash the adsorption resin 3 times, with 1000 g of water used each time and stirred for 30 minutes each time. The wet material after the last water wash enters the toluene extraction kettle;

[0088] (5) Toluene extraction:

[0089] Wash the adsorption resin with 3368 g of toluene at 70 °C until the gasoline and impurity residues are less than 100 ppm, and then recover the toluene;

[0090] (6) Methanol extraction:

[0091] Transfer the material to a methanol extraction kettle, and wash the adsorption resin with 9497 g of methanol at 55 °C until the toluene residue is less than 100 ppm, and then recover the methanol;

[0092] (7) Water washing:

[0093] Transfer the adsorption resin to a water washing kettle, heat water to 60 °C for shower washing, with the water consumption being 1000 g, and continue for 30 minutes;

[0094] (8) Screening and packaging:

[0095] Screen the adsorption resin after water washing, and package it according to different particle size requirements to obtain macroporous adsorption resin.

[0096] Example 2

[0097] A preparation method of macroporous adsorption resin is as follows:

[0098] (1) Material preparation and stirring:

[0099] Mix 300 g of divinylbenzene, 27 g of methyl methacrylate, 225 g of gasoline and 75 g of liquid paraffin in an oil-phase container, add 3.4 g of azobisisobutyronitrile, and stir for 0.5 hour to obtain an oil phase; in another container, heat 856 g of water to 80 °C, add 30 g of a modified functional agent, 25 g of gelatin and 0.01 g of methylene blue, and stir until homogeneous to obtain an aqueous phase;

[0100] (2) Polymerization reaction:

[0101] Mix the oil phase prepared in step (1) and the aqueous phase prepared in step (1), control the temperature at 80 °C until the gel point appears and then continue to keep warm for 2.5 hours, then raise the temperature to 90 °C and keep warm for 6 hours, and finally raise the temperature to 95 °C and keep warm for 3 hours;

[0102] (3) Filtration:

[0103] After the polymerization reaction is completed, cool down to below 70 °C, and use a filtration device to separate the adsorption resin and the reaction wastewater;

[0104] (4) Water washing:

[0105] Wash the adsorption resin 3 times, with the water consumption being 1000 g each time, stir for 30 minutes each time, and the wet material after the last water washing enters the toluene extraction kettle;

[0106] (5) Toluene extraction:

[0107] Wash the adsorption resin with 3368 g of toluene at 70 °C until the gasoline and impurity residues are less than 100 ppm, and then recover the toluene;

[0108] (6) Methanol extraction:

[0109] Transfer the material to a methanol extraction kettle, and wash the adsorption resin with 9497 g of methanol at 55 °C until the toluene residue is less than 100 ppm, and then recover the methanol;

[0110] (7) Water washing:

[0111] Transfer the adsorption resin to a water washing kettle, heat the water to 60 °C for shower washing, the water consumption is 1000 g, and continue for 30 minutes;

[0112] (8) Screening and packaging:

[0113] Screen the adsorption resin after water washing, and package it according to different particle size requirements to obtain macroporous adsorption resin.

[0114] The preparation method of the modified functional agent is as follows:

[0115] S1. First, add 20 parts by weight of lignin to 200 parts by weight of water, and add 0.5 mol / L sodium hydroxide aqueous solution under stirring conditions to adjust the pH value to 10. After continuously stirring for 1 hour, let the mixture stand for 4 hours, then separate the precipitate by suction filtration, and add 0.5 mol / L hydrochloric acid to the filtrate to adjust the pH value to 4, then stand for 11 hours, and after suction filtration, water washing and drying, a pretreatment product is obtained;

[0116] S2. Add the pretreatment product prepared in step S1 to 200 parts by weight of dimethyl sulfoxide, and heat it to 100 °C in an oil bath. At this temperature, add 100 parts by weight of 1-formyl-piperidine-4-carbonyl chloride and continuously stir for 4 hours, then quickly pour the mixture into 500 parts by weight of isopropanol to terminate the reaction, separate the sediment by centrifugation at 10000 rpm, and obtain a post-treatment product by vacuum drying;

[0117] S3. Add the post-treatment product prepared in step S2 to 200 parts by weight of N-methylpyrrolidone, and add 3 parts by weight of phosphoric acid and 0.5 part by weight of triphenylphosphine, and carry out treatment at 100 °C for 8 hours, then remove the solvent by reduced pressure distillation, and remove N-methylpyrrolidone and phosphoric acid by pressure evaporation. Then, use ethyl acetate and methanol for extraction, and wash with water until neutral, and obtain the modified functional agent by drying.

[0118] Example 3

[0119] The preparation method of a macroporous adsorption resin is basically the same as that of Example 2, and the only difference is that the preparation method of the modified functional agent is different.

[0120] The preparation method of the modified functional agent is as follows:

[0121] S1. First, add 20 parts by weight of lignin to 200 parts by weight of water, and add 0.5 mol / L sodium hydroxide aqueous solution under stirring conditions to adjust the pH value to 10. After continuously stirring for 1 hour, let the mixture stand for 4 hours, then separate the precipitate by suction filtration, and add 0.5 mol / L hydrochloric acid to the filtrate to adjust the pH value to 4, and then let it stand for 11 hours. After suction filtration, washing with water and drying, a pretreatment product is obtained;

[0122] S2. Add the pretreatment product prepared in step S1 to 200 parts by weight of dimethyl sulfoxide, and heat it to 100 °C in an oil bath. At this temperature, add 100 parts by weight of linoleoyl chloride and continuously stir for 4 hours, then quickly pour the mixture into 500 parts by weight of isopropanol to terminate the reaction, separate the sediment by centrifugation at 10000 rpm, and obtain a post-treatment product by vacuum drying;

[0123] S3. Add the post-treatment product prepared in step S2 to 200 parts by weight of N-methylpyrrolidone, and add 3 parts by weight of phosphoric acid and 0.5 part by weight of triphenylphosphine, and carry out treatment at 100 °C for 8 hours, then remove the solvent by vacuum distillation, and remove N-methylpyrrolidone and phosphoric acid by pressure evaporation. Then, carry out extraction with ethyl acetate and methanol, and wash with water until neutral, and obtain a modified functional agent by drying.

[0124] Example 4

[0125] A preparation method of macroporous adsorption resin is basically the same as that of Example 2, and the only difference is that the preparation method of the modified functional agent is different.

[0126] The preparation method of the modified functional agent is as follows:

[0127] S1. First, add 20 parts by weight of lignin to 200 parts by weight of water, and add 0.5 mol / L sodium hydroxide aqueous solution under stirring conditions to adjust the pH value to 10. After continuously stirring for 1 hour, let the mixture stand for 4 hours, then separate the precipitate by suction filtration, and add 0.5 mol / L hydrochloric acid to the filtrate to adjust the pH value to 4, and then let it stand for 11 hours. After suction filtration, washing with water and drying, a pretreatment product is obtained;

[0128] S2. Add the pretreatment product prepared in step S1 to 200 parts by weight of dimethyl sulfoxide, and heat it to 100 °C in an oil bath. At this temperature, add 100 parts by weight of cocoyl chloride and continuously stir for 4 hours, then quickly pour the mixture into 500 parts by weight of isopropanol to terminate the reaction, separate the sediment by centrifugation at 10000 rpm, and obtain a post-treatment product by vacuum drying;

[0129] S3. Add the post-treatment product prepared in step S2 to 200 parts by weight of N-methylpyrrolidone, add 3 parts by weight of phosphoric acid and 0.5 part by weight of triphenylphosphine, conduct treatment at 100 °C for 8 hours, then remove the solvent by vacuum distillation, and remove N-methylpyrrolidone and phosphoric acid by pressure evaporation. Next, perform extraction using ethyl acetate and methanol, wash with water until neutral, and obtain the modified functional agent through drying.

[0130] Example 5

[0131] The preparation method of a macroporous adsorption resin is basically the same as that of Example 2, and the only difference lies in the different preparation method of the modified functional agent.

[0132] The preparation method of the modified functional agent is as follows:

[0133] S1. First, add 20 parts by weight of lignin to 200 parts by weight of water, and add 0.5 mol / L sodium hydroxide aqueous solution under stirring conditions to adjust the pH value to 10. After continuously stirring for 1 hour, let the mixture stand for 4 hours, then separate the precipitate by suction filtration, add 0.5 mol / L hydrochloric acid to the filtrate to adjust the pH value to 4, and then let it stand for 11 hours. After suction filtration, washing with water and drying, a pretreatment product is obtained;

[0134] S2. Add the pretreatment product prepared in step S1 to 200 parts by weight of dimethyl sulfoxide, and heat it to 100 °C in an oil bath. At this temperature, add 100 parts by weight of (9ci)-4-amino-cyclohexanecarbonyl chloride and continuously stir for 4 hours, then quickly pour the mixture into 500 parts by weight of isopropanol to terminate the reaction. Separate the sediment by centrifugation at 10000 rpm, and obtain the post-treatment product through vacuum drying;

[0135] S3. Add the post-treatment product prepared in step S2 to 200 parts by weight of N-methylpyrrolidone, add 3 parts by weight of phosphoric acid and 0.5 part by weight of triphenylphosphine, conduct treatment at 100 °C for 8 hours, then remove the solvent by vacuum distillation, and remove N-methylpyrrolidone and phosphoric acid by pressure evaporation. Next, perform extraction using ethyl acetate and methanol, wash with water until neutral, and obtain the modified functional agent through drying.

[0136] Example 6

[0137] The preparation method of a macroporous adsorption resin is basically the same as that of Example 2, and the only difference lies in the different preparation method of the modified functional agent.

[0138] The preparation method of the modified functional agent is as follows:

[0139] S1. First, add 20 parts by weight of lignin to 200 parts by weight of water, and add 0.5 mol / L sodium hydroxide aqueous solution under stirring conditions to adjust the pH value to 10. After continuously stirring for 1 hour, let the mixture stand for 4 hours, then separate the precipitate by suction filtration, and add 0.5 mol / L hydrochloric acid to the filtrate to adjust the pH value to 4, and then let it stand for 11 hours. After suction filtration, washing with water and drying, a pretreatment product is obtained;

[0140] S2. Add the pretreatment product prepared in step S1 to 200 parts by weight of dimethyl sulfoxide, and heat it to 100 °C in an oil bath. At this temperature, add 100 parts by weight of 1-formyl-piperidine-4-carbonyl chloride and continuously stir for 4 hours, then quickly pour the mixture into 500 parts by weight of isopropanol to terminate the reaction, separate the sediment by centrifugation at 10,000 rpm, and obtain a post-treatment product by vacuum drying;

[0141] S3. Add the post-treatment product prepared in step S2 to 200 parts by weight of N-methylpyrrolidone, and add 3 parts by weight of hydrofluoric acid and 0.5 part by weight of triphenylphosphine, and carry out treatment at 100 °C for 8 hours, then remove the solvent by vacuum distillation, and remove N-methylpyrrolidone and hydrofluoric acid by pressure evaporation. Then, carry out extraction with ethyl acetate and methanol, and wash with water until neutral, and obtain a modified functional agent by drying.

[0142] Example 7

[0143] A preparation method of macroporous adsorption resin is basically the same as that of Example 2, and the only difference is that the preparation method of the modified functional agent is different.

[0144] The preparation method of the modified functional agent is as follows:

[0145] S1. First, add 20 parts by weight of lignin to 200 parts by weight of water, and add 0.5 mol / L sodium hydroxide aqueous solution under stirring conditions to adjust the pH value to 10. After continuously stirring for 1 hour, let the mixture stand for 4 hours, then separate the precipitate by suction filtration, and add 0.5 mol / L hydrochloric acid to the filtrate to adjust the pH value to 4, and then let it stand for 11 hours. After suction filtration, washing with water and drying, a pretreatment product is obtained;

[0146] S2. Add the pretreatment product prepared in step S1 to 200 parts by weight of dimethyl sulfoxide, and heat it to 100 °C in an oil bath. At this temperature, add 50 parts by weight of 1-formyl-piperidine-4-carbonyl chloride and 50 parts by weight of (9ci)-4-amino-cyclohexanecarbonyl chloride and continuously stir for 4 hours, then quickly pour the mixture into 500 parts by weight of isopropanol to terminate the reaction, separate the sediment by centrifugation at 10,000 rpm, and obtain a post-treatment product by vacuum drying;

[0147] S3. Add the post-treatment product prepared in step S2 to 200 parts by weight of N-methylpyrrolidone, add 3 parts by weight of phosphoric acid and 0.5 part by weight of triphenylphosphine, carry out treatment at 100 °C for 8 hours, then remove the solvent by vacuum distillation, and remove N-methylpyrrolidone and phosphoric acid by pressure evaporation. Then, carry out extraction with ethyl acetate and methanol, wash with water until neutral, and obtain the modified functional agent through drying.

[0148] Comparative Example 1

[0149] The preparation method of a macroporous adsorption resin is basically the same as that of Example 2, and the only difference lies in the different preparation method of the modified functional agent.

[0150] The preparation method of the modified functional agent is as follows:

[0151] S1. First, add 20 parts by weight of lignin to 200 parts by weight of water, add 0.5 mol / L sodium hydroxide aqueous solution under stirring conditions to adjust the pH value to 10, continue stirring for 1 hour, then let the mixture stand for 4 hours, then separate the precipitate by suction filtration, add 0.5 mol / L hydrochloric acid to the filtrate to adjust the pH value to 4, stand for another 11 hours, and obtain the pretreatment product after suction filtration, washing with water and drying.

[0152] S2. Add the pretreatment product prepared in step S1 to 200 parts by weight of dimethyl sulfoxide, heat to 100 °C in an oil bath, add 100 parts by weight of stearoyl chloride at this temperature and continue stirring for 4 hours, then quickly pour the mixture into 500 parts by weight of isopropanol to terminate the reaction, separate the sediment by centrifugation at 10000 rpm, and obtain the post-treatment product through vacuum drying.

[0153] S3. Add the post-treatment product prepared in step S2 to 200 parts by weight of N-methylpyrrolidone, add 3 parts by weight of phosphoric acid and 0.5 part by weight of triphenylphosphine, carry out treatment at 100 °C for 8 hours, then remove the solvent by vacuum distillation, and remove N-methylpyrrolidone and phosphoric acid by pressure evaporation. Then, carry out extraction with ethyl acetate and methanol, wash with water until neutral, and obtain the modified functional agent through drying.

[0154] Comparative Example 2

[0155] The preparation method of a macroporous adsorption resin is basically the same as that of Example 2, and the only difference lies in the different preparation method of the modified functional agent.

[0156] The preparation method of the modified functional agent is as follows:

[0157] S1. First, add 20 parts by weight of lignin to 200 parts by weight of water, and add 0.5 mol / L sodium hydroxide aqueous solution under stirring conditions to adjust the pH value to 10. After continuous stirring for 1 hour, let the mixture stand for 4 hours, then separate the precipitate by suction filtration, add 0.5 mol / L hydrochloric acid to the filtrate to adjust the pH value to 4, and then let it stand for 11 hours. After suction filtration, washing with water and drying, a pretreated product is obtained.

[0158] S2. Add the pretreated product prepared in step S1 to 200 parts by weight of dimethyl sulfoxide, and heat it to 100 °C in an oil bath. At this temperature, add 100 parts by weight of 1-formyl-piperidine-4-carbonyl chloride and continuously stir for 4 hours, then quickly pour the mixture into 500 parts by weight of isopropanol to terminate the reaction, separate the sediment by centrifugation at 10,000 rpm, and obtain a post-treated product by vacuum drying.

[0159] S3. Add the post-treated product prepared in step S2 to 200 parts by weight of N-methylpyrrolidone, add 3 parts by weight of hydrobromic acid and 0.5 parts by weight of triphenylphosphine, and carry out treatment at 100 °C for 8 hours. Then remove the solvent by vacuum distillation, and remove N-methylpyrrolidone and hydrobromic acid by pressurized evaporation. Then, carry out extraction with ethyl acetate and methanol, and wash with water until neutral. After drying, a modified functional agent is obtained.

[0160] Comparative Example 3

[0161] A preparation method of macroporous adsorption resin is basically the same as that of Example 2, and the only difference is that the modified functional agent is replaced with an equal amount of lignin.

[0162] Test Example 1

[0163] Specific surface area test

[0164] Use a 3H-2000III type full-automatic nitrogen adsorption specific surface area tester and a Malvern MS3000 laser particle size analyzer to test the specific surface area of the macroporous adsorption resin prepared in the examples and comparative examples; the test results are shown in Table 1.

[0165] Table 1

[0166] Experimental Scheme <![CDATA[Specific surface area (m 2 / g)]]> Example 1 682 Example 2 1013 Example 3 975 Example 4 998 Example 5 973 Example 6 977 Example 7 1063 Comparative Example 1 958 Comparative Example 2 953 Comparative Example 3 864

[0167] Test Example 2

[0168] Strength test

[0169] Testing method: Respectively dry 50 g of the macroporous adsorption resins prepared in the examples and comparative examples at 80 °C until the weight loss rate is below 3 wt%, after cooling to room temperature, add 100 mL of absolute ethanol, stir for 5 minutes and then filter dry. Separate the spherical and fragmented adsorption resins, dry them at 80 °C for 2 hours respectively and then weigh them. Calculate the fragmentation rate according to the following formula:

[0170] Fragmentation rate = weight of fragments / (weight of macroporous adsorption resin + weight of fragments) × 100%

[0171] The lower the fragmentation rate, the higher the strength. The test results are shown in Table 2.

[0172] Table 2

[0173] Experimental Scheme Breakage Rate (%) Example 1 4.1 Example 2 2.9 Example 3 3.1 Example 4 3.2 Example 5 3.0 Example 6 3.1 Example 7 2.7 Comparative Example 1 3.3 Comparative Example 2 3.3 Comparative Example 3 3.5

[0174] It can be seen from the data in Tables 1 and 2 that compared with Examples 1 - 6 and Comparative Examples 1 - 3, the macroporous adsorption resin prepared in Example 2 has the largest specific surface area and the smallest fragmentation rate in the strength test.

[0175] 1 - formyl - piperidine - 4 - carbonyl chloride used in Example 2 has a cyclic piperidine group and a carbonyl group in its structure. This structure may provide more cross - linking points and steric hindrances during the preparation of the modified functional agent, thus forming a more stable and uniform network structure in the polymerization reaction. This structure may contribute to increasing the cross - linking density of the resin, improving its mechanical strength, and at the same time maintaining a high specific surface area. This may be because it can more effectively fix polymer chains during the polymerization process, reducing the movement and aggregation of chains, and thus forming more pore structures in the final product. Compared with linolenoyl chloride, coconut oil acyl chloride and stearoyl chloride, the unique structure of 1 - formyl - piperidine - 4 - carbonyl chloride may provide better mechanical stability and a higher specific surface area for the resin. Although linolenoyl chloride and coconut oil acyl chloride can also provide cross - linking of amide bonds, the structure of their linear alkyl chains may not have as good a spatial fixation effect as the cyclic structure of 1 - formyl - piperidine - 4 - carbonyl chloride, which may result in the resins prepared from them having inferior strength and specific surface area compared to Example 2.

[0176] In Example 2, phosphoric acid was used as a catalyst. Due to its strong acidity and catalytic properties, it effectively promoted the selective cleavage of methoxy ether bonds in lignin, generating more phenolic hydroxyl groups. The increase in phenolic hydroxyl groups not only enhanced the reactivity of lignin but also might have improved the compatibility and crosslinking density between the modified functional agent and the resin matrix. The introduction of phenolic hydroxyl groups might have increased the polarity of the resin, improving its interaction with polar solvents, thereby forming more pore structures during the polymerization process and increasing the specific surface area. At the same time, the presence of phenolic hydroxyl groups might have enhanced the mechanical strength of the resin and reduced the breakage rate. Compared with hydrofluoric acid and hydrobromic acid, the use of phosphoric acid in Example 2 might be more conducive to controlling the reaction rate and selectivity due to its mild acidity and catalytic effect, avoiding side reactions and structural damage that might be caused by an overly fast reaction rate. Although hydrofluoric acid has strong catalytic activity, its high corrosiveness and the possible introduction of fluoride impurities might be unfavorable for the stability and environmental friendliness of the resin. Hydrobromic acid might have a lower catalytic efficiency than phosphoric acid due to its weaker acidity, resulting in a smaller amount of phenolic hydroxyl groups being generated, thus affecting the specific surface area and strength of the resin. Therefore, the use of phosphoric acid showed advantages in improving the performance of macroporous adsorption resins.

[0177] In Example 7, 1-formyl-piperidine-4-carbonyl chloride and (9ci)-4-amino-cyclohexanecarbonyl chloride were used in combination to prepare the modified functional agent. Compared with using only one of the acyl chlorides alone, it might be because these two compounds provided different active sites and crosslinking mechanisms during the reaction. 1-formyl-piperidine-4-carbonyl chloride provided the piperidine ring and the carbonyl group, while (9ci)-4-amino-cyclohexanecarbonyl chloride introduced the amino group and the cyclohexane ring. This combination might have enhanced the intermolecular forces of the modified functional agent, thereby forming a more uniform and stable resin network structure during the polymerization process. This structure not only increased the crosslinking density of the resin and the specific surface area but also might have improved the mechanical strength of the resin by enhancing intermolecular hydrogen bonds and van der Waals forces, thus reducing the breakage rate.

Claims

1. A method for preparing a macroporous adsorption resin, characterized in that: The method comprises the following steps, in parts by weight: (1) Preparation and mixing: 200-400 parts of divinylbenzene, 20-30 parts of methyl methacrylate and 250-330 parts of solvent are mixed in an oil phase container, 3-4 parts of initiator are added, and stirred for 0.3-0.8 hours to obtain an oil phase; in another container, 800-900 parts of water are heated to 70-90° C., 20-40 parts of a functional modification agent, 20-30 parts of gelatin and 0.005-0.02 parts of methylene blue are added, and stirred until uniform to obtain an aqueous phase; (2) Polymerization reaction: The oil phase prepared in step (1) and the water phase prepared in step (1) are mixed, and the temperature is controlled at 70-90° C. until the gel point appears, and the mixture is kept warm for 2-3 hours, then the temperature is raised to 80-95° C. and kept warm for 4-8 hours, and finally the temperature is raised to 90-98° C. and kept warm for 2-4 hours; (3) Filtering: After the polymerization reaction is completed, the temperature is lowered to below 60-80°C, and a filtration device is used to separate the adsorption resin and the reaction wastewater; (4) Washing: The adsorption resin is washed with water for 1 to 3 times, each time with 800 to 1200 parts of water, and each time is stirred for 20 to 40 minutes. The wet material after the last water washing enters the toluene extraction kettle; (5) Toluene extraction: The adsorption resin is eluted with 3000-4000 parts of toluene at 60-80°C until the gasoline and impurities remain less than 80-120 ppm, and then the toluene is recovered; (6) Methanol extraction: The material is transferred to a methanol extraction kettle, and the adsorption resin is eluted with 9000-10000 parts of methanol at 50-60°C until the residual toluene is less than 80-120 ppm, and then the methanol is recovered; (7) Washing: Transfer the adsorption resin to a water washing kettle, heat water to 50-70°C for elution, use 800-1200 parts of water, and continue for 20-40 minutes; (8) Screening and packaging: The washed adsorption resin is sieved and packaged according to different particle size requirements to obtain a macroporous adsorption resin; The preparation method of the modified functional agent is as follows, in parts by weight: S1. First, 15 to 25 parts of lignin are added to 180 to 220 parts of water, and a pH alkaline regulator is added under stirring to adjust the pH value to 9 to 11. After continuous stirring for 0.5 to 2 hours, the mixture is allowed to stand for 3 to 5 hours, and then the precipitate is separated by suction filtration, and a pH acidic regulator is added to the filtrate to adjust the pH value to 3 to 5, and then the filtrate is allowed to stand for 8 to 15 hours. After suction filtration, washing and drying, a pretreated product is obtained; S2, adding the pre-treated product prepared in step S1 to 180-220 parts of dimethyl sulfoxide, and heating to 90-110° C. in an oil bath, at this temperature, adding 80-120 parts of 1-formyl-piperidine-4-carbonyl chloride and continuously stirring for 3-5 hours, and then quickly pouring the mixture into 400-600 parts of isopropanol to terminate the reaction, separating the sediment by centrifugation, and obtaining a post-treated product by vacuum drying; S3, adding the post-treated product prepared in step S2 to 180-220 parts of N-methylpyrrolidone, and adding 2-4 parts of phosphoric acid and 0.4-0.6 parts of triphenylphosphine, treating at 80-120° C. for 5-10 hours, then removing the solvent by reduced pressure distillation, and removing N-methylpyrrolidone and phosphoric acid by pressurized evaporation, then extracting with ethyl acetate and methanol, washing with water to neutrality, and drying to obtain a modified functional agent; The solvent is gasoline.

2. The method for preparing the macroporous adsorption resin according to claim 1, characterized in that: The initiator is azobisisobutyronitrile.

3. The method for preparing the macroporous adsorption resin according to claim 1, characterized in that: The pH alkaline regulator is a 0.4-0.6 mol / L sodium hydroxide aqueous solution.

4. The method for preparing the macroporous adsorption resin according to claim 1, characterized in that: The pH acidity regulator is 0.4-0.6 mol / L hydrochloric acid.

5. The method for preparing the macroporous adsorption resin according to claim 1, characterized in that: The centrifugal speed of the centrifugal separation sediment is 8000~12000rpm.

6. A macroporous adsorption resin, characterized in that The method is prepared by the preparation method according to any one of claims 1 to 5.