A method for preparing macroporous weak base anion exchange resin

Abstract

The present invention relates to the technical field of resin preparation, and in particular to a method for preparing a macroporous weak-base anion exchange resin. Styrene, divinylbenzene, benzoyl peroxide and a porogen are mixed to obtain an organic mixture; water, gelatin and a methylene blue solution are mixed to obtain a gelatin solution; the organic mixture and the gelatin solution are mixed and then heat-treated to obtain a polystyrene-divinylbenzene copolymer; the polystyrene-divinylbenzene copolymer is mixed and swollen with chloromethyl ether to obtain a swollen product; a chloromethylation catalyst is added to the swollen product in batches and then stirred and reacted in turn with heat to obtain a qualified chlorine ball; the qualified chlorine ball is mixed with water and an amine reagent and then heat-insulated to obtain a macroporous weak-base anion exchange resin. The method provided by the present invention has simple process, low energy consumption, high exchange capacity, good mechanical strength, high anti-penetration ability and heat resistance, and has a good effect on the treatment of organic waste liquid.

Description

Technical Field

[0001] The invention relates to the technical field of resin preparation, in particular to a method for preparing a macroporous weak-base anion exchange resin. Background Art

[0002] Anion exchange resins have a wide range of uses, such as drinking water, industrial wastewater treatment, separation and purification of biochemical products and chemical drug components, as well as natural products and effective components of Chinese herbal medicines. Traditional gel anion resins cannot meet the requirements in terms of pollution resistance and mechanical strength. In view of the shortcomings of gel-type anion exchange resins, macroporous anion exchange resins have been developed. Macroporous ion exchange resins are opaque in appearance, rough on the surface, and have a heterogeneous gel structure. Macroporous anion exchange resins have a permanent, large-diameter physical pore structure, which makes macroporous ion exchange resins superior to gel-type anion resins in terms of pollution resistance, mechanical strength, pollution resistance and other performance.

[0003] With the continuous development of the chemical and metallurgical industries, a large number of harmful or difficult-to-degrade pollutants are generated. These pollutants are the focus of environmental governance, among which the treatment of organic acid waste liquid is the top priority of environmental governance. The main methods of removal are adsorption and ion exchange. The adsorption method mainly removes water pollutants through hydrophobic action, but its conventional adsorption resin has a weak effect on these anionic pollutants and a low adsorption capacity. The ion exchange method is stronger for ionic compounds in water, but when harmful or difficult-to-degrade anions coexist with other ions in the aqueous solution, the exchange capacity and adsorption selectivity of the ion exchange resin will be reduced, and the resin has poor heat resistance and a short service life. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a method for preparing a macroporous weak base anion exchange resin. The method provided by the present invention has a simple process and low energy consumption. Compared with traditional macroporous weak base resins, the method has a higher exchange capacity, good mechanical strength, high anti-penetration ability and heat resistance, has a better effect on the treatment of organic waste liquid, and has excellent application prospects and market potential.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] The present invention provides a method for preparing a macroporous weak base anion exchange resin, comprising the following steps:

[0007] 1) mixing styrene, divinylbenzene, benzoyl peroxide and a porogen to obtain an organic mixture;

[0008] 2) mixing water, gelatin and methylene blue solution to obtain a gelatin solution;

[0009] 3) mixing the organic mixture obtained in step 1) and the gelatin solution obtained in step 2) and then heat-treating the mixture to obtain a polystyrene-divinylbenzene copolymer;

[0010] 4) mixing the polystyrene-divinylbenzene copolymer obtained in step 3) with chloromethyl ether and swelling the mixture to obtain a swollen product;

[0011] 5) adding a chloromethylation catalyst dropwise to the swollen product obtained in step 4), followed by stirring reaction and thermal reaction, to obtain chlorine balls;

[0012] 6) The chlorine balls obtained in step 5) are mixed with water and an amine reagent and then subjected to a heat-insulating reaction to obtain a macroporous weak base anion exchange resin.

[0013] Preferably, in step 1), the mass ratio of styrene, divinylbenzene, benzoyl peroxide and porogen is 168-176:15-20:2.4-3:100.

[0014] Preferably, the porogen includes one or more of isobutyl alcohol, toluene and normal oil.

[0015] Preferably, in step 2), the volume ratio of water, gelatin and methylene blue solution is 100 mL: 1 g: 1-2 mL;

[0016] The mass percentage content of the methylene blue solution is 0.1%.

[0017] Preferably, the volume ratio of the mass of the organic mixture in step 3) to the gelatin solution is 285.4-299 g:201-202 mL.

[0018] Preferably, the heat treatment conditions in step 3) include: keeping warm at 75-80°C for 2-3 hours, keeping warm at 80-85°C for 1-2 hours, and finally keeping warm at 90-100°C for 5-6 hours.

[0019] Preferably, in step 4), the volume ratio of the mass of the polystyrene-divinylbenzene copolymer to the chloromethyl ether is 100 g:600 mL;

[0020] The swelling conditions include: temperature of 20° C. and time of 2 to 3 hours.

[0021] Preferably, the mass ratio of the chloromethylation catalyst to the polystyrene-divinylbenzene copolymer in step 5) is 1:10;

[0022] The chloromethylation catalyst includes one or more of aluminum chloride, ferric chloride and zinc chloride;

[0023] The stirring reaction conditions include: temperature of 25°C, time of 1h, and rotation speed of 120rpm;

[0024] The conditions of the thermal reaction include: a temperature of 40 to 50° C. and a time of 10 to 15 hours.

[0025] Preferably, in step 6), the mass ratio of the chlorine ball to water and the amine reagent is 1:1:2.5;

[0026] The amine reagent includes ethylenediamine and / or propylenediamine.

[0027] Preferably, the conditions for the heat preservation reaction in step 6) include: a temperature of 50 to 60° C. and a time of 8 to 10 hours.

[0028] Beneficial effects of the present invention:

[0029] The method provided by the invention has simple process, low energy consumption, high exchange capacity, good mechanical strength, high anti-penetration ability and heat resistance, good effect on organic waste liquid treatment, and excellent application prospect and market potential. DETAILED DESCRIPTION

[0030] The present invention provides a method for preparing a macroporous weak base anion exchange resin, comprising the following steps:

[0031] 1) mixing styrene, divinylbenzene, benzoyl peroxide and a porogen to obtain an organic mixture;

[0032] 2) mixing water, gelatin and methylene blue solution to obtain a gelatin solution;

[0033] 3) mixing the organic mixture obtained in step 1) and the gelatin solution obtained in step 2) and then heat-treating the mixture to obtain a polystyrene-divinylbenzene copolymer;

[0034] 4) mixing the polystyrene-divinylbenzene copolymer obtained in step 3) with chloromethyl ether and swelling the mixture to obtain a swollen product;

[0035] 5) adding a chloromethylation catalyst dropwise to the swollen product obtained in step 4), followed by stirring reaction and thermal reaction, to obtain chlorine balls;

[0036] 6) The chlorine balls obtained in step 5) are mixed with water and an amine reagent and then subjected to a heat-insulating reaction to obtain a macroporous weak base anion exchange resin.

[0037] The present invention mixes styrene, divinylbenzene, benzoyl peroxide and a porogen to obtain an organic mixture. In the present invention, the mass ratio of styrene, divinylbenzene, benzoyl peroxide and porogen is preferably 168-176:15-20:2.4-3:100. In the present invention, the benzoyl peroxide is used as an initiator. In the present invention, the divinylbenzene is used as a crosslinking agent. In the present invention, the porogen preferably includes one or more of isobutyl alcohol, toluene and normal oil.

[0038] The present invention mixes water, gelatin and methylene blue solution to obtain a gelatin solution. In the present invention, the volume ratio of the water, the mass of the gelatin and the methylene blue solution is preferably 100mL:1g:1-2mL. In the present invention, the mass percentage of the methylene blue solution is preferably 0.1%. In the present invention, the gelatin acts as a dispersant. In the present invention, the methylene blue acts as an indicator. The present invention preferably mixes the water and gelatin, completely dissolves the gelatin at 50°C, and then mixes with the methylene blue solution.

[0039] The present invention mixes the obtained organic mixture with the gelatin solution and then performs heat treatment to obtain a polystyrene-divinylbenzene copolymer. In the present invention, the particle size of the polystyrene-divinylbenzene copolymer is preferably 0.4-0.6 mm. In the present invention, the mass ratio of the organic mixture to the gelatin solution is preferably 285.4-299 g: 201-202 mL. In the present invention, the heat treatment conditions preferably include: keeping warm at a temperature of 75-80°C for 2-3 hours, then keeping warm at a temperature of 80-85°C for 1-2 hours, and finally keeping warm at a temperature of 90-100°C for 5-6 hours.

[0040] The present invention mixes the obtained polystyrene-divinylbenzene copolymer with chloromethyl ether and swells it to obtain a swollen product. In the present invention, the chloromethyl ether is used as a chloromethylation agent. In the present invention, the mass ratio of the polystyrene-divinylbenzene copolymer to the volume ratio of the chloromethyl ether is preferably 100g:600mL. In the present invention, the swelling conditions preferably include: a temperature of 20°C and a time of 2 to 3h.

[0041] The present invention adds a chloromethylation catalyst dropwise to the obtained swollen product, and then performs a stirring reaction and a thermal reaction in sequence to obtain a chlorine ball. In the present invention, the chloromethylation catalyst preferably includes one or more of aluminum chloride, ferric chloride and zinc chloride. In the present invention, the mass ratio of aluminum chloride to polystyrene-divinylbenzene copolymer is preferably 1:10. In the present invention, the conditions for the stirring reaction preferably include: a temperature of 25°C, a time of 1h, and a rotation speed of 100rpm. In the present invention, the conditions for the thermal reaction preferably include: a temperature of 40-50°C and a time of 10-15h.

[0042] The present invention mixes the obtained chlorine balls with water and an amine reagent and then performs a heat preservation reaction to obtain a macroporous weak base anion exchange resin. In the present invention, the mass ratio of the chlorine balls to water and the amine reagent is preferably 1:1:2.5. In the present invention, the amine reagent preferably includes ethylenediamine and / or propylenediamine. In the present invention, the heat preservation reaction conditions preferably include: a temperature of 50 to 60°C and a time of 8 to 10 hours.

[0043] In order to further illustrate the present invention, the present invention is described in detail below in conjunction with embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0044] Example 1

[0045] A method for preparing a macroporous weak base anion exchange resin comprises the following steps:

[0046] (1) Suspension polymerization:

[0047] Stir 176 g of the raw material monomers styrene, 16 g of divinylbenzene, 2.8 g of benzoyl peroxide and 100 g of isobutyl alcohol into a homogeneous organic mixture;

[0048] Add 200g of deionized water and 1g of gelatin into a three-necked flask, stir and heat to 50°C, and after the gelatin is completely dissolved, add 1ml of 0.1% methylene blue solution:

[0049] Add the homogeneous organic mixture into a three-necked flask, stir and heat, set the stirring speed, and adjust the appropriate particle size to 0.5 mm. When the temperature rises to 75°C, keep it warm for 3 hours, when the temperature rises to 85°C, keep it warm for 1 hour, and when the temperature rises to 95°C, keep it warm for 5 hours to synthesize polystyrene-divinylbenzene copolymer;

[0050] After washing with hot water three times, filtering out impurities and unreacted oligomers, drying to a moisture content of less than 5%, and sieving, 175 g of a polystyrene-divinylbenzene copolymer of suitable particle size was obtained, with a particle size of 0.5 mm.

[0051] (2) Chlorination reaction:

[0052] Place 100 g of the qualified polystyrene-divinylbenzene copolymer obtained in step (1) and 600 mL of chloromethyl ether in a three-necked flask and allow to swell at 20° C. for 2 h;

[0053] Weigh 10 g of aluminum chloride and add it into a three-necked flask in three batches. Stir and react at 25°C for 1 hour, then at 50°C for 10 hours. After the reaction is completed, filter and wash with water to obtain 185 g of qualified chlorine balls with a chlorine content of 18% (mass percentage).

[0054] (3) Amination reaction:

[0055] In a round-bottom flask equipped with a temperature indicating device, a reflux condenser and an electric stirrer, add all the qualified chlorine balls in step (2), add 200 mL of water and stir, slowly drop 250 g of ethylenediamine at room temperature at a rate of 2 ml per second to carry out amination reaction, and control the reaction temperature at 30°C;

[0056] After the addition was completed, the reaction temperature was controlled at 60°C and kept for 8 hours;

[0057] After the reaction is completed, the mixture is filtered and washed with water to obtain 420 g of macroporous weak base anion exchange resin A with a total exchange capacity (hereinafter referred to as "total exchange") of 5.0 mmol / g, a water content of 56%, and a ball grinding rate of 98%.

[0058] Example 2

[0059] A method for preparing a macroporous weak base anion exchange resin comprises the following steps:

[0060] (1) Suspension polymerization:

[0061] Stir 176 g of the raw material monomers styrene, 15 g of divinylbenzene, 2.4 g of benzoyl peroxide and 100 g of toluene into a homogeneous organic mixture;

[0062] Add 200g of deionized water and 1g of gelatin into a three-necked flask, stir and heat to 50°C, and after the gelatin is completely dissolved, add 2mL of 0.1% methylene blue solution:

[0063] Add the homogeneous organic mixture into a three-necked flask, stir and heat, set the stirring speed, and adjust the appropriate particle size to 0.55 mm. When the temperature rises to 75°C, keep it warm for 2 hours, when the temperature rises to 85°C, keep it warm for 1 hour, and when the temperature rises to 96°C, keep it warm for 5 hours to synthesize polystyrene-divinylbenzene copolymer;

[0064] After washing with hot water three times, filtering out impurities and unreacted oligomers, drying to a moisture content of less than 5%, and sieving, 172 g of polystyrene-divinylbenzene copolymer of suitable particle size was obtained, with a particle size of 0.55 mm

[0065] (2) Chlorination reaction:

[0066] Place 100 g of the qualified polystyrene-divinylbenzene copolymer prepared in step (1) and 600 mL of chloromethyl ether in a three-necked flask and allow to swell at 20° C. for 3 h;

[0067] Weigh 10g of ferric chloride and add it to a three-necked flask in three batches. Stir and react at 25℃ for 1h, then at 50℃ for 12h. After the reaction is finished, filter and wash with water to obtain 190g of qualified chlorine balls with a chlorine content of 18% (mass percentage).

[0068] (3) Amination reaction:

[0069] In a round-bottom flask equipped with a temperature indicating device, a reflux condenser and an electric stirrer, add all the qualified chlorine balls in step (2), add 200 mL of water and stir, slowly drop 250 g of ethylenediamine at room temperature at a rate of 2 ml per second to carry out amination reaction, and control the reaction temperature at 30°C;

[0070] After the addition was completed, the reaction temperature was controlled at 60°C and kept for 8 hours;

[0071] After the reaction was completed, the mixture was filtered and washed with water to obtain 420 g of macroporous weak base anion exchange resin B with a total exchange capacity (hereinafter referred to as "total exchange") of 4.9 mmol / g, a water content of 55%, and a ball grinding rate of 98%.

[0072] Example 3

[0073] A method for preparing a macroporous weak base anion exchange resin comprises the following steps:

[0074] (1) Suspension polymerization:

[0075] Stir 168 g of the raw material monomers styrene, 20 g of divinylbenzene, 3 g of benzoyl peroxide and 100 g of normal oil into a homogeneous organic mixture;

[0076] Add 200g of deionized water and 1g of gelatin into a three-necked flask, stir and heat to 50°C, and after the gelatin is completely dissolved, add 2mL of 0.1% methylene blue solution:

[0077] Add the homogeneous organic mixture into a three-necked flask, stir and heat, set the stirring speed, and adjust the appropriate particle size to 0.53 mm. When the temperature rises to 75°C, keep it warm for 2 hours, when the temperature rises to 85°C, keep it warm for 1 hour, and when the temperature rises to 96°C, keep it warm for 5 hours to synthesize polystyrene-divinylbenzene copolymer;

[0078] After washing with hot water three times, filtering out impurities and unreacted oligomers, drying to a moisture content of less than 5%, and sieving, 168 g of polystyrene-divinylbenzene copolymer of suitable particle size was obtained, with a particle size of 0.53 mm

[0079] (2) Chlorination reaction:

[0080] Place 100 g of the qualified polystyrene-divinylbenzene copolymer obtained in step (1) and 600 mL of chloromethyl ether in a three-necked flask and allow to swell at 20° C. for 2 h;

[0081] Weigh 10g of zinc chloride and add it to a three-necked flask in three batches. Stir and react at 25℃ for 1h, then at 50℃ for 12h. After the reaction is finished, filter and wash with water to obtain 200g of qualified chlorine balls with a chlorine content of 18% (mass percentage).

[0082] (3) Amination reaction:

[0083] In a round-bottom flask equipped with a temperature indicating device, a reflux condenser and an electric stirrer, add all the qualified chlorine balls in step (2), add 200 mL of water and stir, slowly drop 250 g of ethylenediamine at room temperature at a rate of 2 ml per second to carry out amination reaction, and control the reaction temperature at 30°C;

[0084] After the addition was completed, the reaction temperature was controlled at 60°C and kept for 10 hours;

[0085] After the reaction was completed, the mixture was filtered and washed with water to obtain a macroporous weak base anion exchange resin C 400g with a total exchange capacity (hereinafter referred to as "total exchange") of 4.8mmol / g, a water content of 57%, and a ball grinding rate of 99%.

[0086] Example 4

[0087] Heat resistance test of macroporous weak base anion exchange resin:

[0088] (1) Take 30 g of macroporous weak base anion exchange resin D301, A, B, C, centrifuge and dry, and divide into two portions, each 15 g.

[0089] (2) One set of resin exchange capacity and water content tested in accordance with GB / T 5760-2000 Determination of exchange capacity of hydroxyl type anion exchange resin.

[0090] (3) Place another portion of resin in a single-necked flask, add 100 ml of pure water, add a spherical condenser, place in a water bath, and keep the temperature at 100°C for 120 hours. During the constant temperature process, the water in the pot must not dry out. If the water volume in the single-necked flask decreases, it is necessary to add boiled pure water in time.

[0091] After 120 hours of constant temperature, the sample was taken out and dried to test the resin exchange capacity and water content. The experimental results are shown in Table 1.

[0092] Table 1 Heat resistance test of macroporous weak base anion exchange resin

[0093]

[0094] It can be concluded from Table 1 that, compared with the conventional macroporous weak base resin D301, the macroporous weak base resin prepared by the new method has better heat resistance.

[0095] Example 5

[0096] Resin anti-penetration performance test:

[0097] (1) The method for repeated osmotic pressure shock test is as follows: 15 ml of macroporous weak base anion exchange resin D301, A, B, and C are loaded into the exchange column respectively, and 5 cycles of osmotic pressure shock test are performed. Each cycle includes the following steps:

[0098] (2) Pass 5 BV (5 times the volume of the resin) of 1 mol / L chemically pure NaOH solution at a flow rate of 6 mL / min for 10 min, and soak for 5 min after completion.

[0099] (3) Pass 20 BV of deionized water at a flow rate of 16 mL / min for 15 min.

[0100] (4) Pass 5 BV of 1 mol / L HCl solution at a flow rate of 6 mL / min for 10 min, and soak for 5 min after completion.

[0101] (5) Pass 20 BV of deionized water at a flow rate of 16 mL / min for 15 min.

[0102] (6) The above operation was repeated 5 times, and then the sample's grinding ball rate was tested. The experimental results are shown in Table 2.

[0103] Table 2 Macroporous weak base anion exchange resin infiltration ball rate

[0104]

[0105]

[0106] It can be concluded from Table 2 that after 5 cycles of repeated osmotic pressure shock, the balling rate is still above 90%. Compared with the conventional macroporous weak base resin D301, the macroporous weak base resin prepared by the new method has better anti-penetration ability.

[0107] Example 6

[0108] Organic waste liquid treatment experiment

[0109] Experimental conditions

[0110] 1 Experimental water: organic wastewater provided by a company, with COD 1200mg / L.

[0111] 2 Experimental equipment and instruments: glass exchange column Φ25x300, measuring cylinder, beaker, constant flow pump, etc.

[0112] Experimental methods

[0113] 1 Take macroporous weak base resins D301, A, B, and C and load them into glass exchange columns respectively, keeping no bubbles in the resin layer and keeping a 5 cm water layer on the resin layer.

[0114] 2. Run the organic wastewater from top to bottom through the resin layer at a flow rate of 2BV / h for a total of 10 hours. Take the effluent every two hours, test the COD, and record the test data. The experimental results are shown in Table 3.

[0115] Table 3 Macroporous weak base anion exchange resin organic acid waste liquid treatment experiment

[0116]

[0117] It can be concluded from Table 3 that after 10 hours of operation, the macroporous weak base resin prepared by the new method has a better treatment effect on organic waste liquid compared with the conventional macroporous weak base resin D301.

[0118] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for preparing a macroporous weak base anion exchange resin, characterized in that: The following steps are involved: 1) mixing styrene, divinylbenzene, benzoyl peroxide and a porogen to obtain an organic mixture; 2) mixing water, gelatin and methylene blue solution to obtain a gelatin solution; 3) mixing the organic mixture obtained in step 1) and the gelatin solution obtained in step 2) and then heat-treating the mixture to obtain a polystyrene-divinylbenzene copolymer; 4) mixing the polystyrene-divinylbenzene copolymer obtained in step 3) with chloromethyl ether and swelling the mixture to obtain a swollen product; 5) adding a chloromethylation catalyst dropwise to the swollen product obtained in step 4), followed by stirring reaction and thermal reaction, to obtain chlorine balls; 6) The chlorine balls obtained in step 5) are mixed with water and an amine reagent and then subjected to a heat-insulating reaction to obtain a macroporous weak base anion exchange resin.

2. The preparation method according to claim 1, characterized in that: In the step 1), the mass ratio of styrene, divinylbenzene, benzoyl peroxide and porogen is 168-176:15-20:2.4-3:

100.

3. The preparation method according to claim 1 or 2, characterized in that: The porogen includes one or more of isobutyl alcohol, toluene and normal oil.

4. The preparation method according to claim 1, characterized in that: In step 2), the volume ratio of water, gelatin and methylene blue solution is 100 mL: 1 g: 1-2 mL; The mass percentage content of the methylene blue solution is 0.1%.

5. The preparation method according to claim 1, characterized in that: The mass ratio of the organic mixture in step 3) to the gelatin solution is 285.4-299 g: 201-202 mL.

6. The preparation method according to claim 1, characterized in that: The heat treatment conditions in step 3) include: keeping warm at a temperature of 75-80° C. for 2-3 hours, keeping warm at a temperature of 80-85° C. for 1-2 hours, and finally keeping warm at a temperature of 90-100° C. for 5-6 hours.

7. The preparation method according to claim 1, characterized in that: In the step 4), the volume ratio of the mass of the polystyrene-divinylbenzene copolymer to chloromethyl ether is 100 g:600 mL; The swelling conditions include: temperature of 20° C. and time of 2 to 3 hours.

8. The preparation method according to claim 1, characterized in that: The mass ratio of the chloromethylation catalyst to the polystyrene-divinylbenzene copolymer in step 5) is 1:10; The chloromethylation catalyst includes one or more of aluminum chloride, ferric chloride and zinc chloride; The stirring reaction conditions include: temperature of 25°C, time of 1h, and rotation speed of 100rpm; The conditions of the thermal reaction include: a temperature of 40 to 50° C. and a time of 10 to 15 hours.

9. The preparation method according to claim 1, characterized in that: In step 6), the mass ratio of chlorine ball, water and amine reagent is 1:1:2.5; The amine reagent includes ethylenediamine and / or propylenediamine.

10. The preparation method according to claim 1, characterized in that: The conditions for the heat preservation reaction in step 6) include: a temperature of 50 to 60° C. and a time of 8 to 12 hours.

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