A modified resin, its preparation method and application

Abstract

This application belongs to the field of functional polymer materials technology, specifically relating to a modified resin, its preparation method, and its application. The preparation method of the modified resin provided in this application includes the following steps: swelling a matrix resin and reacting it with an aminopyrimidine compound to obtain the modified resin; wherein the matrix resin includes a macroporous resin with an average pore size of 10-80 nm. The aminopyrimidine-modified resin provided in this application is used for the removal of organic matter from process exhaust gas, significantly reducing the total organic matter content in the exhaust gas, allowing for direct and safe emission into the atmosphere without the need for high-investment, high-energy-consuming treatment methods such as incineration. This process is simple to operate, stable in operation, and highly automated, significantly reducing investment and operating costs and achieving compliant emissions of exhaust gas.

Description

Technical Field

[0001] This application belongs to the field of functional polymer materials technology, specifically relating to a modified resin, its preparation method, and its application. Background Technology

[0002] Isocyanates are important organic reaction intermediates, widely used in industries such as home appliances, automobiles, construction, footwear, furniture, and adhesives. Currently, most industrial production methods for isocyanates employ the phosgenation method, which involves mixing a primary amine with an inert solvent, followed by a phosgenation reaction with phosgene and a series of post-processing steps.

[0003] In the phosgenation production of isocyanates, the main processes involve phosgene synthesis, phosgenation reaction, and isocyanate product refining. At each stage, process tail gases are discharged to a tail gas treatment system. These tail gases contain not only conventional gases such as nitrogen, carbon monoxide, and carbon dioxide, but also a large amount of acidic gases, such as phosgene and hydrogen chloride, as well as a certain amount of reaction solvents and light organic byproducts. Conventional methods for treating organic matter involve adsorption with activated carbon before release into the atmosphere or incineration. However, adsorption with activated carbon suffers from low adsorption efficiency, posing a risk of excessive organic matter in the tail gas. Furthermore, activated carbon is prone to pulverization during use, has a short lifespan, and requires frequent replacement. This necessitates the addition of online organic matter analyzers or frequent monitoring, resulting in high operating costs and a heavy workload for personnel. Incineration of the tail gas requires a complete incineration system, representing a significant investment and wasting solvent resources.

[0004] The prior art also discloses a method for treating exhaust gas during the preparation of isocyanates, including a hydrogen chloride gas absorption process, a chlorine and organic component absorption process, an oxygen absorption process, and a phosgene decomposition process. This technology requires limiting the concentration of organic matter in the exhaust gas through front-end process control, but the concentration of organic matter in the exhaust gas is still higher than the environmental emission standards, and the organic matter in the exhaust gas still needs further treatment. Summary of the Invention

[0005] Therefore, the technical problem to be solved by this application is to overcome the defects in the prior art, such as the excessive concentration of organic matter in the exhaust gas generated during the preparation of isocyanates and failure to meet environmental emission standards, thereby providing a modified resin, its preparation method and application.

[0006] Therefore, this application provides the following technical solution:

[0007] According to one aspect of this application, a method for preparing a modified resin is provided, comprising the following steps:

[0008] The base resin is swollen and then reacted with an aminopyrimidine compound to obtain a modified resin.

[0009] The matrix resin includes a macroporous resin, wherein the average pore size of the macroporous resin is 10-80 nm.

[0010] As an example, the average pore size of the macroporous resin may be 10nm, 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, or within any range of the above values.

[0011] In some alternative embodiments, the mass ratio of the matrix resin to the aminopyrimidine compound is 1:(1-5); as an example, the mass ratio of the matrix resin to the aminopyrimidine compound is 1:1, 1:2, 1:3, 1:4, 1:5, or within any range of the above values.

[0012] And / or, the aminopyrimidine compounds include at least one of 5-aminopyrimidine, 2-aminopyrimidine, and triaminopyrimidine.

[0013] In some optional embodiments, the modification reaction temperature is 50-120°C; the modification reaction time is 1-10 h; and the stirring speed is 20-100 r / min. For example, the modification reaction temperature is 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, or any range thereof; the modification reaction time is 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h, 10 h, or any range thereof; and the stirring speed is 20 r / min, 30 r / min, 40 r / min, 50 r / min, 60 r / min, 70 r / min, 80 r / min, 90 r / min, 100 r / min, or any range thereof.

[0014] Optionally, the modification reaction temperature is 60-100℃; the modification reaction time is 2-6h; and the stirring speed is 30-60r / min.

[0015] In some alternative embodiments, the swelling operation includes immersing the matrix resin in an organic solvent;

[0016] Optionally, the soaking time is 5-20 hours, optionally 10-15 hours, and the mass ratio of the matrix resin to the organic solvent is 1:(5-20). As an example, the soaking time is 5 hours, 7 hours, 9 hours, 10 hours, 12 hours, 14 hours, 15 hours, or within any of the above values; the mass ratio of the matrix resin to the organic solvent is 1:5, 1:8, 1:10, 1:13, 1:15, 1:17, 1:20, or within any of the above values.

[0017] In some optional embodiments, the method for preparing the matrix resin includes: mixing a monovinyl reactive monomer, a polyvinyl crosslinking agent, a porogen, an initiator, a dispersant, a surfactant, and water, and carrying out a polymerization reaction to obtain the matrix resin;

[0018] Optionally, the mass ratio of the monovinyl reactive monomer to the polyvinyl crosslinker is 1:(1-10); as an example, the mass ratio of the monovinyl reactive monomer to the polyvinyl crosslinker is 1:1, 1:2, 1:3, 1:5, 1:7, 1:9, 1:10, or within any of the above values.

[0019] In this application, the monovinyl reactive monomer includes at least one of aromatic monovinyl monomers or acrylate monovinyl monomers; typically, without limitation, the aromatic monovinyl monomers include, but are not limited to, at least one of vinylpyridine compounds, styrene, methylstyrene, ethylstyrene, chlorostyrene, and bromostyrene; the acrylate monovinyl monomers include, but are not limited to, at least one of acrylates and methacrylates; specifically, they may be methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, etc. The polyvinyl crosslinking agent includes at least one of divinylbenzene, dimethyl propylene glycol, polyvinyl acrylate compounds, and tristyrene.

[0020] Further optionally, the monovinyl reactive monomer comprises a vinylpyridine compound, wherein the vinylpyridine compound comprises at least one of vinylpyridine and 2-methyl-5-vinylpyridine;

[0021] And / or, the polyvinyl crosslinking agent comprises polyvinyl acrylate compounds, which include at least one of dimethyl ethylene glycol acrylate, 1,6-hexanediol diacrylate, trimethylolpropane trimethacrylate, and allyl methacrylate.

[0022] In some alternative embodiments, the polymerization reaction temperature is controlled at 20-110°C; the polymerization reaction time is 1-10 h; and the stirring speed is 20-100 r / min. For example, the polymerization reaction temperature is controlled at 20°C, 30°C, 50°C, 60°C, 70°C, 90°C, 100°C, 110°C, or within any range of the above values; the polymerization reaction time is 1 h, 3 h, 5 h, 7 h, 9 h, 10 h, or within any range of the above values; and the stirring speed is 20 r / min, 30 r / min, 40 r / min, 50 r / min, 60 r / min, 70 r / min, 80 r / min, 90 r / min, 100 r / min, or within any range of the above values.

[0023] Optionally, the polymerization reaction temperature is controlled at 40-80℃; the polymerization reaction time is 2-6h; and the stirring speed is 30-60r / min.

[0024] In some alternative embodiments, the mass ratio of the aqueous phase to the oil phase is (1-20):1. For example, the mass ratio of the aqueous phase to the oil phase is 1:1, 3:1, 5:1, 8:1, 10:1, 12:1, 15:1, 17:1, 20:1, or within any range of the above values.

[0025] The aqueous phase includes dispersants, surfactants, and water, while the oil phase includes monovinyl reactive monomers, polyvinyl crosslinking agents, pore-forming agents, and initiators.

[0026] In some alternative embodiments, the mass percentage of dispersant is 0.2%-2% and the mass percentage of surfactant is 0.2%-2% based on the total mass of the aqueous phase; as an example, the mass percentage of dispersant in the aqueous phase is 0.2%, 0.5%, 0.8%, 1%, 1.3%, 1.5%, 1.7%, 2%, or within any range of the above values; the mass percentage of surfactant is 0.2%, 0.5%, 0.8%, 1%, 1.3%, 1.5%, 1.7%, 2%, or within any range of the above values.

[0027] And / or, based on the total mass of the oil phase, the porogen comprises 2%-20% by mass and the initiator comprises 1%-5% by mass; as an example, the porogen in the oil phase comprises 2%, 5%, 8%, 10%, 13%, 15%, 17%, 20%, or any of the above values; the initiator comprises 1%, 2%, 3%, 4%, 5%, or any of the above values.

[0028] According to another aspect of this application, a modified resin prepared by the above-described preparation method is provided.

[0029] According to another aspect of this application, the application of the above-mentioned modified resin in removing organic matter from process tail gas is provided;

[0030] Optionally, the process exhaust gas is isocyanate production exhaust gas.

[0031] In some optional embodiments, the specific preparation method of the modified resin may include the following steps:

[0032] (a) Preparation of matrix resin: Add appropriate amounts of vinylpyridine compounds, acrylate compounds, porogens, initiators, dispersants, surfactants and water to a reaction vessel, stir and carry out polymerization reaction. After the reaction is completed, wash with anhydrous ethanol and deionized water in sequence until neutral, and dry under vacuum to obtain matrix resin.

[0033] (b) Preparation of modified resin: The matrix resin was soaked in an organic solvent to swell, and an aminopyrimidine compound was added. The mixture was stirred and heated to react. After the reaction was completed, the resin was washed with anhydrous ethanol and deionized water until neutral. The resin was then dried under vacuum to obtain an aminopyrimidine modified resin.

[0034] In some alternative embodiments, in step (a), the pore-forming agent may be any one or more of benzene, toluene, polyethylene glycol, white oil, liquid paraffin, C6-C25 alkanes or alkanols.

[0035] In some alternative embodiments, in step (a), the initiator may be one or more of benzoyl peroxide, sodium percarbonate, sodium persulfate, tert-butyl peroxide, dicumyl peroxide, cumyl hydroperoxide, and azobisisobutyronitrile.

[0036] In some alternative embodiments, in step (a), the dispersant may be one or more of polyvinyl alcohol, gelatin, fatty acids, aliphatic amides, paraffins, cellulose, etc.

[0037] In some alternative embodiments, in step (a), the surfactant is one or more of sodium dodecyl sulfonate, sodium dodecyl sulfate, sodium secondary alkyl sulfonate, docosyl glycerol ester, and fatty acid diglyceride.

[0038] In some optional embodiments, after the reaction in step (a) is completed, a washing step is further included, specifically comprising: immersing the polymerized matrix resin in anhydrous ethanol for 1-3 hours, followed by immersion in deionized water for 1-3 hours.

[0039] In some alternative embodiments, in step (a), after the resin is washed with water until neutral, it is placed in a vacuum drying oven under a nitrogen atmosphere and dried at a temperature of 40-60°C for 2-10 hours to obtain the matrix resin.

[0040] In some alternative embodiments, the organic solvent used in step (b) for the swelling step may be one or more of methanol, ethanol, dichloromethane, dichloroethane, n-hexane, and dioxane.

[0041] In some optional embodiments, step (b) further includes a washing step after the reaction is complete. Specifically, the aminopyrimidine-modified resin is immersed in anhydrous ethanol for 1-3 hours. Then, it is immersed in deionized water for 1-3 hours.

[0042] In some alternative embodiments, in step (b), the drying temperature is 50-80°C and the drying time is 2-10 hours to obtain the modified resin.

[0043] In this application, the organic compounds in the process tail gas include one or more of chlorinated alkanes, chlorinated olefins, chlorinated aromatics, alkyl esters, carbonates, toluene, and xylene.

[0044] The total organic matter content in the exhaust gas is 0.01%-10%, preferably 0.05%-5%, more preferably 0.1%-2%, with the remainder being gases such as nitrogen, carbon monoxide, and carbon dioxide.

[0045] In this application, the process for removing organic matter from the process tail gas is a continuous adsorption process.

[0046] In some alternative embodiments, the process method described in this application involves sending the process tail gas (isocyanate production tail gas) to a resin tower for adsorption, and the treated tail gas is directly discharged into the atmosphere. After the resin is saturated with adsorption, it is regenerated by steam desorption, and the regenerated resin is recycled for adsorption.

[0047] In some alternative embodiments, the number of resin towers is 2-4, one of which is in a regeneration state, and the adsorption method is single-unit or 2-3 units in series adsorption.

[0048] In some alternative embodiments, the adsorption temperature of the resin tower is 10-50°C, preferably 15-25°C.

[0049] In some alternative embodiments, the resin tower space velocity is 100-1200 h⁻¹. -1 Preferably 200-1000h -1 More preferably 300-600h -1 .

[0050] In some alternative embodiments, the adsorption cycle of the resin tower is 1-50 hours, preferably 2-30 hours, and more preferably 4-10 hours.

[0051] In some alternative embodiments, the regeneration temperature of the resin tower is 100-140°C, preferably 110-130°C.

[0052] In some alternative embodiments, the resin tower regeneration time is 0.5-4 hours, preferably 1-2 hours.

[0053] In some optional embodiments, after the organic matter in the process tail gas (isocyanate production tail gas) of this application is treated with modified resin, the total organic matter content in the tail gas can be reduced to less than 20 ppm, preferably less than 5 ppm.

[0054] The technical solution of this application has the following advantages:

[0055] The method for preparing the modified resin provided in this application includes the following steps: swelling a matrix resin and reacting it with an aminopyrimidine compound to obtain the modified resin; wherein the matrix resin includes a macroporous resin with an average pore size of 10-80 nm. The aminopyrimidine-modified resin provided in this application is used for the removal of organic matter from process tail gas, significantly reducing the total organic matter content in the tail gas, allowing for direct and safe emission into the atmosphere without the need for high-investment, high-energy-consuming treatment methods such as incineration. This process is simple to operate, stable in operation, and highly automated, significantly reducing investment and operating costs and achieving compliant emissions of tail gas. Specifically, this application modifies a macroporous resin with a specific pore size using aminopyrimidine, adding functional groups while maintaining a high degree of molecular cross-linking. This provides the resin with numerous adsorption sites such as amine groups and N=C structures, resulting in a large specific surface area and strong selective adsorption. In addition to adsorbing conventional non-polar organic gases, it also exhibits excellent specific adsorption of chlorine-containing organic gases, achieving an adsorption removal rate of over 99.6% for organic matter.

[0056] The modified resin preparation method provided in this application, by preferably using vinylpyridine compounds as the reaction monomers of the macroporous resin and acrylate compounds as the polyvinyl crosslinking agents, can further improve the adsorption performance of the resin and increase the adsorption and removal rate of organic matter in the process tail gas to up to 99.94%. Attached Figure Description

[0057] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0058] Figure 1 This is a process flow diagram of the process tail gas treatment in the test examples of this application;

[0059] Figure label:

[0060] 1. Process tail gas; 2. Primary resin adsorption tower; 3. Primary resin tower outlet gas; 4. Secondary resin adsorption tower; 5. Emission tail gas; 6. Steam; 7. Desorption resin tower; 8. Desorption waste liquid. Detailed Implementation

[0061] The following embodiments are provided to better understand this application and are not limited to the preferred embodiments described herein. They do not constitute a limitation on the content and scope of protection of this application. Any product that is the same as or similar to this application, derived by anyone under the guidance of this application or by combining features of this application with other prior art, falls within the scope of protection of this application.

[0062] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0063] In the following examples and comparative examples, the main sources of raw materials are as follows:

[0064] Vinylpyridine (99.5%, Sinopharm Reagent Co., Ltd.);

[0065] Dimethyl ethylene glycol acrylate (98.5%, Aladdin Reagent Co., Ltd.);

[0066] Toluene (analytical grade, Sinopharm Reagent Co., Ltd.);

[0067] Polyethylene glycol (average molecular weight 600, analytical grade, Sinopharm Reagent Co., Ltd.);

[0068] Azobisisobutyronitrile (99.0%, Sinopharm Reagent Co., Ltd.);

[0069] Gelatin (food grade, Zhejiang Yicun Biotechnology);

[0070] Sodium secondary alkyl sulfonate SAS60 (RSO3Na (R=C12~C16, Shandong Yousuo Chemical);

[0071] 2-Aminopyrimidine (99.5%, Sinopharm Reagent Co., Ltd.);

[0072] Anhydrous ethanol (99.8%, Sinopharm Reagent Co., Ltd.);

[0073] n-Hexane (99.8%, Sinopharm Reagent Co., Ltd.);

[0074] Liquid paraffin (Sinopharm Reagent Co., Ltd.);

[0075] Benzoyl peroxide (99%, Sinopharm Reagent Co., Ltd.);

[0076] Polyvinyl alcohol (average molecular weight 20,000, Aladdin Reagent Co., Ltd.);

[0077] Sodium dodecyl sulfonate (98%, Sinopharm Reagent Co., Ltd.);

[0078] Methanol (99.9%, Aladdin Reagent Co., Ltd.);

[0079] Sodium percarbonate (99%, Aladdin Reagent Co., Ltd.);

[0080] Hydroxypropyl methylcellulose (98%, Sinopharm Reagent Co., Ltd.);

[0081] Dodecaneglyceride (99%, Sinopharm Reagent Co., Ltd.);

[0082] Dioxane (97%, Sinopharm Reagent Co., Ltd.);

[0083] Styrene (99.5%, West Asia Reagent Co., Ltd.);

[0084] Divinylbenzene (99%, West Asia Reagent Co., Ltd.);

[0085] tert-Butylstyrene (99%, Aladdin Reagent Co., Ltd.);

[0086] Allyl methacrylate (98%, Sinopharm Reagent Co., Ltd.)

[0087] Example 1

[0088] This embodiment provides a modified resin, the specific preparation method and operating parameters of which are as follows:

[0089] (a) Preparation of the matrix resin: Appropriate amounts of vinylpyridine, dimethyl ethylene glycol acrylate, toluene (a pore-forming agent), azobisisobutyronitrile (azobisisobutyronitrile), gelatin (a dispersant), sodium secondary alkyl sulfonate (a surfactant), and water were added to a reaction vessel. The mixture was stirred and heated to a temperature of 60°C for 4 hours. The stirring speed was 45 r / min. The mass ratio of the aqueous phase to the oil phase was 10:1. The mass percentages of the dispersant and surfactant in the aqueous phase were 1% and 1% respectively. The mass percentages of the pore-forming agent and the initiator in the oil phase were 10% and 3% respectively. The mass ratio of vinylpyridine to dimethyl ethylene glycol acrylate was 1:5. After the reaction, the polymerized matrix resin was washed with anhydrous ethanol for 2 hours, then washed with deionized water for 2 hours. After the resin reached neutrality, it was placed in a vacuum drying oven under a nitrogen atmosphere at 50°C for 6 hours to obtain the matrix resin with an average pore size of 25 nm.

[0090] (b) Preparation of modified resin: The matrix resin was soaked in the organic solvent n-hexane for swelling for 12 h, with a mass ratio of matrix resin to organic solvent of 1:12. Aminopyrimidine was added, with a mass ratio of matrix resin to aminopyrimidine of 1:3. The mixture was stirred and heated to a temperature of 80 °C for 4 h, with a stirring speed of 45 r / min. After the reaction, the aminopyrimidine-modified resin was washed with anhydrous ethanol for 2 h, then washed with deionized water for 2 h. After washing with deionized water until neutral, the resin was vacuum dried at 70 °C for 6 h to obtain the modified aminopyrimidine resin.

[0091] Example 2

[0092] This embodiment provides a modified resin, the specific preparation method and operating parameters of which are as follows:

[0093] (a) Preparation of the matrix resin: Appropriate amounts of vinylpyridine, dimethyl ethylene glycol acrylate, toluene (a pore-forming agent), azobisisobutyronitrile (azobisisobutyronitrile), gelatin (a dispersant), sodium secondary alkyl sulfonate (a surfactant), and water were added to a reaction vessel. The mixture was stirred and heated to a temperature of 20°C for 10 hours. The stirring speed was 100 r / min. The mass ratio of the aqueous phase to the oil phase was 1:1. The mass percentages of the dispersant and surfactant in the aqueous phase were 2% and 2% respectively. The mass percentages of the pore-forming agent and the initiator in the oil phase were 2% and 1% respectively. The mass ratio of vinylpyridine to dimethyl ethylene glycol acrylate was 1:1. After the reaction, the polymerized matrix resin was washed with anhydrous ethanol for 1 hour, then washed with deionized water for 1 hour. After the resin reached neutrality, it was placed in a vacuum drying oven under a nitrogen atmosphere at 40°C for 2 hours to obtain the matrix resin with an average pore size of 32 nm.

[0094] (b) Preparation of modified resin: The matrix resin was soaked in the organic solvent n-hexane for swelling for 5 hours, with a mass ratio of matrix resin to organic solvent of 1:5. Aminopyrimidine was added, with a mass ratio of matrix resin to aminopyrimidine of 1:1. The mixture was stirred and heated to a temperature of 50°C for 10 hours, with a stirring speed of 100 r / min. After the reaction, the aminopyrimidine-modified resin was washed with anhydrous ethanol for 1 hour, followed by washing with deionized water for 1 hour. The mixture was then washed with deionized water until neutral, and vacuum dried at 50°C for 2 hours to obtain the modified aminopyrimidine resin.

[0095] Example 3

[0096] This embodiment provides a modified resin, the specific preparation method and operating parameters of which are as follows:

[0097] (a) Preparation of the matrix resin: Appropriate amounts of vinylpyridine, dimethyl ethylene glycol acrylate, toluene (a pore-forming agent), azobisisobutyronitrile (azobisisobutyronitrile), gelatin (a dispersant), sodium secondary alkyl sulfonate (a surfactant), and water were added to a reaction vessel. The mixture was stirred and heated to a temperature of 110°C for 1 hour, with a stirring speed of 20 r / min. The mass ratio of the aqueous phase to the oil phase was 20:1. The aqueous phase contained 0.2% dispersant and 0.2% surfactant. The oil phase contained 20% pore-forming agent and 5% initiator. The mass ratio of vinylpyridine to dimethyl ethylene glycol acrylate was 1:10. After the reaction, the polymerized matrix resin was washed with anhydrous ethanol for 3 hours, followed by washing with deionized water for 3 hours. After the resin reached neutrality, it was placed in a vacuum drying oven under a nitrogen atmosphere at 60°C for 10 hours to obtain the matrix resin with an average pore size of 45 nm.

[0098] (b) Preparation of modified resin: The matrix resin was soaked in the organic solvent n-hexane for swelling for 20 h, with a mass ratio of matrix resin to organic solvent of 1:20. Aminopyrimidine was added, with a mass ratio of matrix resin to aminopyrimidine of 1:5. The mixture was stirred and heated to a temperature of 120 °C for 1 h, with a stirring speed of 20 r / min. After the reaction, the aminopyrimidine-modified resin was washed with anhydrous ethanol for 3 h, followed by washing with deionized water for 3 h. The resin was then washed with deionized water until neutral, and vacuum dried at 80 °C for 10 h to obtain the modified aminopyrimidine resin.

[0099] Example 4

[0100] This embodiment provides a modified resin, the specific preparation method and operating parameters of which are as follows:

[0101] (a) Preparation of the matrix resin: Appropriate amounts of vinylpyridine, dimethyl ethylene glycol acrylate, toluene (a pore-forming agent), azobisisobutyronitrile (azobisisobutyronitrile), gelatin (a dispersant), sodium secondary alkyl sulfonate (a surfactant), and water were added to a reaction vessel. The mixture was stirred and heated to a temperature of 40°C for 6 hours. The stirring speed was 60 r / min. The mass ratio of the aqueous phase to the oil phase was 5:1. The mass percentages of the dispersant and surfactant in the aqueous phase were 1.5% and 1.5%, respectively. The mass percentages of the pore-forming agent and the initiator in the oil phase were 5% and 2%, respectively. The mass ratio of vinylpyridine to dimethyl ethylene glycol acrylate was 1:3. After the reaction, the polymerized matrix resin was washed with anhydrous ethanol for 1.5 hours, then washed with deionized water for 1.5 hours. After the resin reached neutrality, it was placed in a vacuum drying oven under a nitrogen atmosphere at 45°C for 4 hours to obtain the matrix resin with an average pore size of 68 nm.

[0102] (b) Preparation of modified resin: The matrix resin was soaked in the organic solvent n-hexane for swelling for 10 h, with a mass ratio of matrix resin to organic solvent of 1:10. Aminopyrimidine was added, with a mass ratio of matrix resin to aminopyrimidine of 1:2. The mixture was stirred and heated to a temperature of 60 °C for 6 h, with a stirring speed of 60 r / min. After the reaction, the aminopyrimidine-modified resin was washed with anhydrous ethanol for 1.5 h. Then, it was washed with deionized water for 1.5 h. After washing with deionized water until neutral, it was vacuum dried at 60 °C for 4 h to obtain the modified aminopyrimidine resin.

[0103] Example 5

[0104] This embodiment provides a modified resin, the specific preparation method and operating parameters of which are as follows:

[0105] (a) Preparation of the matrix resin: Appropriate amounts of vinylpyridine, dimethyl ethylene glycol acrylate, toluene (a pore-forming agent), azobisisobutyronitrile (azobisisobutyronitrile), gelatin (a dispersant), sodium secondary alkyl sulfonate (a surfactant), and water were added to a reaction vessel. The mixture was stirred and heated to a temperature of 80°C for 2 hours. The stirring speed was 30 r / min. The mass ratio of the aqueous phase to the oil phase was 15:1. The aqueous phase contained 0.5% dispersant and 0.5% surfactant. The oil phase contained 15% pore-forming agent and 4% initiator. The mass ratio of vinylpyridine to dimethyl ethylene glycol acrylate was 1:8. After the reaction, the polymerized matrix resin was washed with anhydrous ethanol for 2.5 hours, then washed with deionized water for another 2.5 hours. After the resin reached neutrality, it was placed in a vacuum drying oven under a nitrogen atmosphere at 55°C for 8 hours to obtain the matrix resin with an average pore size of 40 nm.

[0106] (b) Preparation of modified resin: The matrix resin was soaked in the organic solvent n-hexane for swelling for 15 h, with a mass ratio of matrix resin to organic solvent of 1:15. Aminopyrimidine was added, with a mass ratio of matrix resin to aminopyrimidine of 1:4. The mixture was stirred and heated to a temperature of 100 °C for 2 h, with a stirring speed of 30 r / min. After the reaction, the aminopyrimidine-modified resin was washed with anhydrous ethanol for 2.5 h. Then, it was washed with deionized water for 2.5 h. After washing with deionized water until neutral, it was vacuum dried at 75 °C for 8 h to obtain the modified resin.

[0107] Example 6

[0108] This embodiment provides a modified resin, which differs from Example 1 only in that: the porogen is liquid paraffin, the initiator is benzoyl peroxide, the dispersant is polyvinyl alcohol, the surfactant is sodium dodecyl sulfonate, and the organic solvent is methanol.

[0109] Example 7

[0110] This embodiment provides a modified resin, which differs from Example 1 only in that: the porogen is polyethylene glycol, the initiator is sodium percarbonate, the dispersant is hydroxypropyl methylcellulose, the surfactant is docosanoglyceride, and the organic solvent is dioxane.

[0111] Example 8

[0112] This embodiment provides a modified resin, which differs from Example 1 only in that the reactant monomer is styrene and the crosslinking agent is divinylbenzene.

[0113] Example 9

[0114] This embodiment provides a modified resin, which differs from Example 1 only in that: the reactant monomer is tert-butylstyrene and the crosslinking agent is allyl methacrylate.

[0115] Comparative Example 1

[0116] This comparative example directly uses the matrix resin from Example 1.

[0117] Comparative Example 2

[0118] This comparative example provides a modified resin, which differs from Example 9 only in that an equal mass of pyrimidine is used instead of aminopyrimidine.

[0119] Comparative Example 3

[0120] This comparative example provides a modified resin, which differs from Example 9 only in that an equal mass of 4-aminopyridine is used instead of aminopyrimidine.

[0121] Test case

[0122] The modified resins or matrix resins provided in the various embodiments and comparative examples are used for the removal of organic matter from the tail gas of isocyanate production. The process flow is as follows: Figure 1 As shown in the example, this test case uses a two-stage series adsorption and a one-stage desorption and regeneration method in a resin tower to treat organic matter in the exhaust gas. However, this application is not limited to this method. The specific steps and operating parameters are as follows:

[0123] (1) The tail gas 1 from the isocyanate production process at 20°C with a total organic matter mass concentration of approximately 0.5% (see Table 1) is sent to the primary resin adsorption tower 2. The concentration of chlorobenzene in the tail gas is 0.2%, and the space velocity of the adsorption tower is 500 h⁻¹. -1 ;

[0124] (2) After the exhaust gas is adsorbed by the primary resin adsorption tower 2, the outlet gas 3 of the primary resin tower is sent to the secondary resin adsorption tower 4 for series adsorption. The qualified exhaust gas at the outlet of the secondary resin adsorption tower is discharged into the atmosphere (i.e., exhaust gas 5).

[0125] (3) The desorption resin tower 7 is regenerated with 2 barg steam 6, and the desorption waste liquid 8 is sent to the subsequent wastewater treatment system. The regeneration temperature is 125℃ and the regeneration time is 1.5h. After the regeneration is completed, wait is required.

[0126] (4) The adsorption cycle of the primary and secondary resin adsorption towers is 6 hours. After the adsorption cycle ends, the primary resin adsorption tower is switched to the desorption resin tower, the secondary adsorption tower is switched to the primary adsorption tower, and the desorption resin tower is switched to the secondary adsorption tower.

[0127] (5) The above steps are repeated to achieve a continuous two-stage series adsorption and one-stage desorption regeneration process, thereby obtaining qualified exhaust gas.

[0128] Methods for measuring total organic matter in exhaust gas before and after treatment:

[0129] The total organic matter content in the exhaust gas was determined by gas chromatography. First, the organic components in the exhaust gas were diluted with dichloromethane and anhydrous ethanol to prepare standard solutions of different concentrations. Gas chromatography was used for analysis, and a standard curve was plotted on Excel using peak area and concentration. Then, the organic matter in the isocyanate production exhaust gas was absorbed with anhydrous ethanol, and the sample peak area was measured using gas chromatography. The concentration was calculated using the standard curve.

[0130] Detector: Agilent 7890A, chromatographic column HP-5 (30m × 0.25um × 320μm). Chromatographic conditions: Column temperature: 50℃ for 0.5min, ramp up to 80℃ at 5℃ / min and hold for 1min; ramp up to 280℃ at 10℃ / min and hold for 10min; Injector temperature: 280℃; Detector temperature: 295℃; Septum purge gas flow rate: 3.0mL / min; Carrier gas (nitrogen) flow rate: 3mL / min; Air flow rate: 350mL / min; Hydrogen flow rate: 35mL / min; Make-up gas (nitrogen) flow rate: 25mL / min; Split injection, split ratio 1:10; Injection volume: 0.5μL.

[0131] The specific test results are shown in the table below:

[0132] Table 1

[0133]

[0134]

[0135] The data in the table above show that macroporous resins modified with aminopyrimidine compounds provide a large number of amine groups and N=C structures while ensuring a high degree of molecular cross-linking, thereby improving the resin's specific adsorption capacity for organic matter.

[0136] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for preparing a modified resin, characterized in that, Includes the following steps: The base resin is swollen and then reacted with an aminopyrimidine compound to obtain a modified resin. The matrix resin includes a macroporous resin, wherein the average pore size of the macroporous resin is 10-80 nm. The mass ratio of the matrix resin to the aminopyrimidine compound is 1:(1-5). The aminopyrimidine compounds include at least one of 5-aminopyrimidine, 2-aminopyrimidine, and triaminopyrimidine; The method for preparing the matrix resin includes: mixing a monovinyl reactive monomer, a polyvinyl crosslinking agent, a pore-forming agent, an initiator, a dispersant, a surfactant, and water, and carrying out a polymerization reaction to obtain the matrix resin.

2. The method for preparing the modified resin according to claim 1, characterized in that, The modification reaction temperature is 50-120℃; the modification reaction time is 1-10h; and the stirring speed is 20-100r / min.

3. The method for preparing the modified resin according to claim 2, characterized in that, The modification reaction temperature is 60-100℃; the modification reaction time is 2-6h; and the stirring speed is 30-60r / min.

4. The method for preparing the modified resin according to any one of claims 1-3, characterized in that, The swelling operation includes: immersing the matrix resin in an organic solvent; And / or, the mass ratio of the monovinyl reactive monomer to the polyvinyl crosslinker is 1:(1-10). And / or, the monovinyl reactive monomer includes at least one of aromatic monovinyl monomers or acrylate monovinyl monomers; And / or, the polyvinyl crosslinking agent includes at least one of divinylbenzene, dimethyl propylene glycol, polyvinyl acrylate compounds, and tristyrene.

5. The method for preparing the modified resin according to claim 4, characterized in that, The soaking time is 5-20 hours, and the mass ratio of the matrix resin to the organic solvent is 1:(5-20). And / or, the monovinyl reactive monomer comprises a vinylpyridine compound, wherein the vinylpyridine compound comprises at least one of vinylpyridine and 2-methyl-5-vinylpyridine; And / or, the polyvinyl crosslinking agent comprises polyvinyl acrylate compounds, wherein the polyvinyl acrylate compounds comprise at least one of dimethyl ethylene glycol acrylate, 1,6-hexanediol diacrylate, and trimethylolpropane trimethacrylate.

6. The method for preparing the modified resin according to claim 5, characterized in that, The polymerization reaction temperature is 20-110℃; the polymerization reaction time is 1-10h; and the stirring speed is 20-100r / min. And / or, the soaking time is 10-15 hours.

7. The method for preparing the modified resin according to claim 6, characterized in that, The mass ratio of aqueous phase to oil phase is (1-20):

1. The aqueous phase includes a dispersant, a surfactant, and water, and the oil phase includes a monovinyl reactive monomer, a polyvinyl crosslinking agent, a pore-forming agent, and an initiator. And / or, the polymerization reaction temperature is 40-80℃; the polymerization reaction time is 2-6h; and the stirring speed is 30-60r / min.

8. The method for preparing the modified resin according to claim 7, characterized in that, Based on the total mass of the aqueous phase, the dispersant accounts for 0.2%-2% of the mass, and the surfactant accounts for 0.2%-2% of the mass. And / or, based on the total mass of the oil phase, the pore-forming agent accounts for 2%-20% of the mass, and the initiator accounts for 1%-5% of the mass.

9. A modified resin prepared by the preparation method according to any one of claims 1-8.

10. The application of the modified resin according to claim 9 in the removal of organic matter from process tail gas.

11. The application according to claim 10, characterized in that, The process exhaust gas is isocyanate production exhaust gas.

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