Hydroxymethyl self-crosslinking cation exchange resin containing sulfonic acid structure and preparation method and application thereof

Abstract

The application provides a hydroxymethyl self-crosslinking cation exchange resin containing a sulfonic acid structure and a preparation method and application thereof, and relates to the technical field of cation exchange resins.The sulfonation degree is controlled by controlling the content of the sulfonic acid structure unit, the crosslinking degree is controlled by controlling the content of the hydroxymethyl structure unit, and thus the ion exchange capacity is controlled.The hydroxymethyl self-crosslinking cation exchange resin containing a sulfonic acid structure has high ion exchange capacity and has important potential application value in the fields of water treatment, new energy battery electrolyte, natural medicine purification, oil exploitation and the like.The hydroxymethyl self-crosslinking cation exchange resin containing a sulfonic acid structure can be prepared through one-step reaction, does not need to be sulfonated by using concentrated sulfuric acid, the preparation process is more simple and safe than the traditional concentrated sulfuric acid sulfonation process, the reaction condition is more mild, environmental protection, the product yield is high, the product is easy to separate, the production cost is low, and the application is suitable for industrialized production.

Description

Technical Field

[0001] This invention relates to the field of cation exchange resin technology, specifically to a sulfonic acid-containing hydroxymethyl self-crosslinking cation exchange resin, its preparation method, and its application. Background Technology

[0002] Sulfonic acid group-containing cation exchange resins are an important class of functional polymer materials with wide applications in water treatment, serving as key materials for the preparation of ultrapure water and drinking water. They can also be used as solid-state gel electrolytes in new energy lithium-ion batteries, further improving battery efficiency and safety. Furthermore, sulfonic acid group-containing cation exchange resins have significant applications in natural drug separation, food purification, and oil extraction. However, existing sulfonic acid group-containing cation exchange resins have relatively low ion exchange capacities and insufficient ion exchange capabilities. Therefore, researching high-ion-exchange-capacity cation exchange resins with sulfonic acid group structures has significant academic research and practical application value. Summary of the Invention

[0003] In view of this, the purpose of this invention is to provide a sulfonic acid-containing hydroxymethyl self-crosslinking cation exchange resin, its preparation method, and its application. The sulfonic acid-containing hydroxymethyl self-crosslinking cation exchange resin provided by this invention has a high ion exchange capacity.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0005] This invention provides a sulfonic acid-containing hydroxymethyl self-crosslinking cation exchange resin having the structure shown in Formula I:

[0006] Formula I;

[0007] Of these, taking the total amount of x, y and z as 100 mol%, the total amount of x is 25~40 mol% and the total amount of y is 10~25 mol%.

[0008] This invention also provides a method for preparing the sulfonic acid-containing hydroxymethyl self-crosslinking cation exchange resin described in the above technical solution, comprising the following steps:

[0009] The monomer, initiator and organic solvent are mixed and subjected to solution polymerization-hydroxy self-crosslinking reaction to obtain the sulfonic acid-containing hydroxymethyl self-crosslinking cation exchange resin;

[0010] The monomers are 2-acrylamido-2-methylpropanesulfonic acid, N-hydroxymethylacrylamide and methyl methacrylate, wherein the content of 2-acrylamido-2-methylpropanesulfonic acid is 25~40 mol and the content of N-hydroxymethylacrylamide is 10~25 mol.

[0011] Preferably, the amount of the initiator is 0.2-1% of the total amount of the monomer.

[0012] Preferably, the initiator includes at least one of benzoyl peroxide and azobisisobutyronitrile.

[0013] Preferably, the organic solvent includes at least one of N,N-dimethylacetamide, N,N-dimethylformamide, and N-methylpyrrolidone.

[0014] Preferably, the mass of the organic solvent is 2 to 6 times the total mass of the monomers.

[0015] Preferably, the solution polymerization-hydroxy self-crosslinking reaction is carried out at a temperature of 70~90℃ for 1~2 hours.

[0016] Preferably, the solution polymerization-hydroxy self-crosslinking reaction further includes: sequentially pulverizing, washing, and drying the self-crosslinking gel polymer obtained from the solution polymerization-hydroxy self-crosslinking reaction.

[0017] Preferably, the detergent for washing includes at least one of ethanol and methanol.

[0018] This invention also provides the application of the sulfonic acid-containing hydroxymethyl self-crosslinking cation exchange resin described in the above technical solution or the sulfonic acid-containing hydroxymethyl self-crosslinking cation exchange resin prepared by the above technical solution in environmental water treatment, new energy battery electrolytes, natural drug purification or oil extraction.

[0019] This invention regulates the degree of sulfonation by controlling the content of sulfonic acid structural units (x value) and the degree of crosslinking by controlling the content of hydroxymethyl structural units (y value), thereby achieving control over the ion exchange capacity. The sulfonic acid-containing hydroxymethyl self-crosslinking cation exchange resin provided by this invention, with a total x value of 25-40 mol% and a total y value of 10-25 mol%, exhibits high ion exchange capacity and has significant potential application value in water treatment, new energy battery electrolytes, natural drug purification, and oil extraction.

[0020] The sulfonic acid-containing hydroxyl self-crosslinking cation exchange resin provided by this invention can be prepared in one step via solution polymerization-hydroxyl self-crosslinking reaction, eliminating the need for sulfonation with concentrated sulfuric acid. This preparation process is simpler and safer than traditional concentrated sulfuric acid sulfonation, with milder and more environmentally friendly reaction conditions. The product yield is high, easily separated, and has low production costs, making it suitable for industrial production. Furthermore, this invention allows control of the sulfonation degree and crosslinking degree of the sulfonic acid-containing hydroxymethyl self-crosslinking cation exchange resin through monomer ratios. Specifically, the sulfonation degree is controlled by the proportion of 2-acrylamido-2-methylpropanesulfonic acid, and the crosslinking degree is controlled by the proportion of N-hydroxymethylacrylamide, thereby achieving control over the ion exchange capacity of the cation exchange resin. Attached Figure Description

[0021] Figure 1 The infrared spectrum of the hydroxymethyl self-crosslinking cation exchange resin containing sulfonic acid structure in Example 1;

[0022] Figure 2 The infrared spectrum of the hydroxymethyl self-crosslinking cation exchange resin with sulfonic acid structure in Example 2;

[0023] Figure 3 The infrared spectrum is shown for the hydroxymethyl self-crosslinking cation exchange resin containing sulfonic acid structure in Example 3. Detailed Implementation

[0024] This invention provides a sulfonic acid-containing hydroxymethyl self-crosslinking cation exchange resin having the structure shown in Formula I:

[0025] Formula I;

[0026] Of these, taking the total amount of x, y and z as 100 mol%, the total amount of x is 25~40 mol% and the total amount of y is 10~25 mol%.

[0027] In a specific embodiment of the present invention, with the total amount of x, y and z being 100 mol%, the total amount of x can be 25 mol%, 26 mol%, 27 mol%, 28 mol%, 29 mol%, 30 mol%, 31 mol%, 32 mol%, 33 mol%, 34 mol%, 35 mol%, 36 mol%, 37 mol%, 38 mol%, 39 mol%, or 40 mol%.

[0028] In a specific embodiment of the present invention, with the total amount of x, y and z being 100 mol%, the total amount of y can be 10 mol%, 11 mol%, 12 mol%, 13 mol%, 14 mol%, 15 mol%, 16 mol%, 17 mol%, 18 mol%, 19 mol%, 20 mol%, 21 mol%, 22 mol%, 23 mol%, 24 mol%, or 25 mol%.

[0029] This invention regulates the degree of sulfonation by controlling the content of sulfonic acid structural units (x value) and the degree of crosslinking by controlling the content of hydroxymethyl structural units (y value), thereby achieving control over the ion exchange capacity. The sulfonic acid-containing hydroxymethyl self-crosslinking cation exchange resin provided by this invention, with a total x value of 25-40 mol% and a total y value of 10-25 mol%, exhibits high ion exchange capacity and has significant potential application value in water treatment, new energy battery electrolytes, natural drug purification, and oil extraction.

[0030] This invention also provides a method for preparing the sulfonic acid-containing hydroxymethyl self-crosslinking cation exchange resin described in the above technical solution, comprising the following steps:

[0031] The monomer, initiator and organic solvent are mixed and subjected to solution polymerization-hydroxy self-crosslinking reaction to obtain the sulfonic acid-containing hydroxymethyl self-crosslinking cation exchange resin;

[0032] The monomers are 2-acrylamido-2-methylpropanesulfonic acid, N-hydroxymethylacrylamide and methyl methacrylate, wherein the content of 2-acrylamido-2-methylpropanesulfonic acid is 25~40 mol and the content of N-hydroxymethylacrylamide is 10~25 mol.

[0033] In this invention, the preparation route of the sulfonic acid-containing hydroxymethyl self-crosslinking cation exchange resin is as follows:

[0034] .

[0035] Unless otherwise specified, the materials and equipment used in this invention are all commercially available products in the field.

[0036] In this invention, the initiator preferably includes at least one of benzoyl peroxide and azobisisobutyronitrile. In this invention, the amount of the initiator is preferably 0.2% to 1% of the total amount of monomers, and in specific embodiments it can be 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, or 1%.

[0037] In this invention, the organic solvent preferably includes at least one selected from N,N-dimethylacetamide, N,N-dimethylformamide, and N-methylpyrrolidone. In this invention, the mass of the organic solvent is preferably 2 to 6 times the total mass of the monomers, and in specific embodiments, it can be 2 times, 2.5 times, 3 times, 3.5 times, 4 times, 4.5 times, 5 times, 5.5 times, or 6 times.

[0038] In this invention, the temperature of the solution polymerization-hydroxy self-crosslinking reaction is preferably 70~90℃, and in specific embodiments it can be 70℃, 75℃, 80℃, 85℃ or 90℃; the time of the solution polymerization-hydroxy self-crosslinking reaction is preferably 1~2h, and in specific embodiments it can be 1h, 1.5h or 2h.

[0039] In this invention, the solution polymerization-hydroxy self-crosslinking reaction preferably further includes: sequentially pulverizing, washing, and drying the self-crosslinking gel polymer obtained from the solution polymerization-hydroxy self-crosslinking reaction. In this invention, the detergent for washing preferably includes at least one of ethanol and methanol; the mass of the detergent is preferably 5 to 10 times the total mass of the monomers, and in specific embodiments, it can be 5, 6, 7, 8, 9, or 10 times. In this invention, the drying temperature is preferably 100 to 180°C, and in specific embodiments, it can be 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, or 180°C; the drying time is preferably 12 to 24 hours, and in specific embodiments, it can be 12 hours, 15 hours, 18 hours, 20 hours, 22 hours, or 24 hours.

[0040] Existing methods for preparing sulfonic acid-containing cation exchange resins primarily involve first preparing cross-linked polystyrene white spheres through suspension copolymerization of styrene and divinylbenzene, followed by sulfonation with concentrated sulfuric acid at a relatively high temperature. This process requires large amounts of highly corrosive sulfuric acid, posing significant safety and environmental risks. Furthermore, the sulfonation reaction following the concentrated sulfuric acid reaction is often difficult to complete, resulting in a low degree of sulfonation, low ion exchange capacity, and weak ion exchange ability in the prepared ion exchange resin. In contrast, the sulfonic acid-containing hydroxyl self-crosslinking cation exchange resin provided by this invention is prepared through a one-step solution polymerization-hydroxyl self-crosslinking reaction, eliminating the need for concentrated sulfuric acid sulfonation. This process is simpler and safer than traditional concentrated sulfuric acid sulfonation, with milder and more environmentally friendly reaction conditions. It also offers higher product yields, easier separation, lower production costs, and suitability for industrial production. Moreover, the present invention can control the degree of sulfonation and crosslinking of sulfonic acid-containing hydroxymethyl self-crosslinking cation exchange resin by monomer ratio. The degree of sulfonation is controlled by the amount of 2-acrylamido-2-methylpropanesulfonic acid, and the degree of crosslinking is controlled by the amount of N-hydroxymethylacrylamide, thereby achieving the control of the ion exchange capacity of the cation exchange resin.

[0041] This invention also provides applications of the sulfonic acid-containing hydroxymethyl self-crosslinking cation exchange resin described in the above-described technical solutions, or the sulfonic acid-containing hydroxymethyl self-crosslinking cation exchange resin prepared by the above-described technical solutions, in environmental water treatment, new energy battery electrolytes, natural drug purification, or oil extraction. This invention controls the degree of sulfonation by adjusting the content of sulfonic acid structural units (x value) and the degree of crosslinking by controlling the content of hydroxymethyl structural units (y value), thereby achieving control over the ion exchange capacity. The sulfonic acid-containing hydroxymethyl self-crosslinking cation exchange resin provided by this invention, with a total x value of 25-40 mol% and a total y value of 10-25 mol%, has a high ion exchange capacity and significant potential application value in water treatment, new energy battery electrolytes, natural drug purification, and oil extraction.

[0042] To further illustrate the present invention, the following detailed description, in conjunction with embodiments, of the sulfonic acid-containing hydroxymethyl self-crosslinking cation exchange resin, its preparation method, and its application, is provided by the present invention, but should not be construed as limiting the scope of protection of the present invention.

[0043] The raw materials and reagents used in the examples are as follows: 2-acrylamido-2-methylpropanesulfonic acid (99% purity), N-hydroxymethylacrylamide (99% purity), and methyl methacrylate (99% purity) were purchased from Anaiji Chemical Reagent Co., Ltd.; benzoyl peroxide (99% purity) and azobisisobutyronitrile (99% purity) were purchased from Shanghai Aladdin Reagent Co., Ltd.; N-methylpyrrolidone, N,N-dimethylacetamide, and N,N-dimethylformamide were purchased from Shanghai Guoyao Group Chemical Reagent Co., Ltd., and were chemically pure. The ion exchange capacity of the cation exchange resin was tested according to the standard GB 8144-1987, "Method for Determination of Cation Exchange Capacity of Cation Exchange Resins".

[0044] Example 1

[0045] 2.0724 g (0.01 mol) of 2-acrylamido-2-methylpropanesulfonic acid, 1.011 g (0.01 mol) of N-hydroxymethylacrylamide (99% purity) and 2.0024 g (0.02 mol) of methyl methacrylate were added to a dry three-necked flask equipped with a mechanical stirrer and a condenser. 12 mL of N-methylpyrrolidone and 0.02 g of benzoyl peroxide were added, and the mixture was heated to 90 °C and stirred for 1 h to obtain a self-crosslinking gel polymer. The self-crosslinking gel polymer was pulverized, washed with 60 mL of ethanol in several portions, and dried at 180 °C for 12 h to obtain a sulfonic acid-structured hydroxymethyl self-crosslinking cation exchange resin with a yield of 95% and an ion exchange capacity of 1.961 meq / g.

[0046] Figure 1The image shows the infrared spectrum of a hydroxymethyl self-crosslinking cation exchange resin containing a sulfonic acid structure, with the region from 3300 to 3600 cm⁻¹. -1 The absorption peak is broad and at 1151 cm⁻¹ -1 1041cm -1 and 624cm -1 The characteristic absorption peak of sulfonic acid is 2900~3100 cm⁻¹. -1 The absorption peak at 1732 cm⁻¹ is a characteristic absorption peak of alkyl groups. -1 and 1670cm -1 The absorption peaks at 1226 cm⁻¹ are characteristic absorption peaks for ester and amide groups, respectively. -1 The absorption peak at that point is the absorption peak of the cross-linked ether bond.

[0047] Example 2

[0048] 3.1086 g (0.015 mol) of 2-acrylamido-2-methylpropanesulfonic acid, 1.011 g (0.01 mol) of N-hydroxymethylacrylamide (99% purity) and 2.0024 g (0.02 mol) of methyl methacrylate were added to a dry three-necked flask equipped with a mechanical stirrer and a condenser. 18 mL of N,N-dimethylacetamide and 0.04 g of benzoyl peroxide were added, and the mixture was heated to 70 °C and stirred for 2 h to obtain a self-crosslinking gel polymer. The self-crosslinking gel polymer was pulverized, the product was washed several times with 90 mL of methanol, and dried at 100 °C for 24 h to obtain a sulfonic acid-structured hydroxymethyl self-crosslinking cation exchange resin with a yield of 96% and an ion exchange capacity of 2.451 meq / g.

[0049] Figure 2 The image shows the infrared spectrum of a hydroxymethyl self-crosslinking cation exchange resin containing a sulfonic acid structure, with the region from 3300 to 3600 cm⁻¹. -1 The absorption peak is broad and at 1151 cm⁻¹ -1 1041cm -1 and 624cm -1 The characteristic absorption peak of sulfonic acid is 2900~3100 cm⁻¹. -1 The absorption peak at 1731 cm⁻¹ is a characteristic absorption peak of alkyl groups. -1 and 1670cm -1 The absorption peaks at 1220 cm⁻¹ are characteristic absorption peaks for ester and amide groups, respectively. -1 The absorption peak at that point is the absorption peak of the cross-linked ether bond.

[0050] Example 3

[0051] 4.1448 g (0.02 mol) of 2-acrylamido-2-methylpropanesulfonic acid, 1.011 g (0.01 mol) of N-hydroxymethylacrylamide (99% purity) and 2.0024 g (0.02 mol) of methyl methacrylate were added to a dry three-necked flask equipped with a mechanical stirrer and a condenser. 20 mL of N,N-dimethylformamide and 0.065 g of azobisisobutyronitrile were added, and the mixture was heated to 80 °C and stirred for 1.5 h to obtain a self-crosslinking gel polymer. The self-crosslinking gel polymer was pulverized, washed with 120 mL of ethanol in several portions, and dried at 140 °C for 18 h to obtain a sulfonic acid-structured hydroxymethyl self-crosslinking cation exchange resin with a yield of 95% and an ion exchange capacity of 2.793 meq / g.

[0052] Figure 3 The image shows the infrared spectrum of a hydroxymethyl self-crosslinking cation exchange resin containing a sulfonic acid structure, with the region from 3300 to 3600 cm⁻¹. -1 The absorption peak is broad and at 1157 cm⁻¹ -1 1040cm -1 and 629cm -1 The characteristic absorption peak of sulfonic acid is 2900~3100 cm⁻¹. -1 The absorption peak at 1731 cm⁻¹ is a characteristic absorption peak of alkyl groups. -1 and 1677cm -1 The absorption peaks at 1219 cm⁻¹ are characteristic absorption peaks for ester and amide groups, respectively. -1 The absorption peak at that point is the absorption peak of the cross-linked ether bond.

[0053] Example 4

[0054] 2.0724 g (0.01 mol) of 2-acrylamido-2-methylpropanesulfonic acid, 0.5055 g (0.005 mol) of N-hydroxymethylacrylamide (99% purity) and 2.0024 g (0.02 mol) of methyl methacrylate were added to a dry three-necked flask equipped with a mechanical stirrer and a condenser. 15 mL of N-methylpyrrolidone and 0.035 g of benzoyl peroxide were added, and the mixture was heated to 85 °C and stirred for 1 h to obtain a self-crosslinking gel polymer. The self-crosslinking gel polymer was pulverized, the product was washed several times with 70 mL of ethanol, and dried at 120 °C for 16 h to obtain a sulfonic acid-structured hydroxymethyl self-crosslinking cation exchange resin with a yield of 95% and an ion exchange capacity of 2.183 meq / g.

[0055] Example 5

[0056] 4.1448 g (0.02 mol) of 2-acrylamido-2-methylpropanesulfonic acid, 0.5055 g (0.05 mol) of N-hydroxymethylacrylamide (99% purity) and 2.503 g (0.025 mol) of methyl methacrylate were added to a dry three-necked flask equipped with a mechanical stirrer and a condenser. 30 mL of N,N-dimethylformamide and 0.09 g of azobisisobutyronitrile were added, and the mixture was heated to 75 °C and stirred for 1.5 h to obtain a self-crosslinking gel polymer. The self-crosslinking gel polymer was pulverized, washed with 200 mL of ethanol in several portions, and dried at 140 °C for 14 h to obtain a sulfonic acid-structured hydroxymethyl self-crosslinking cation exchange resin with a yield of 94% and an ion exchange capacity of 2.796 meq / g.

[0057] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A hydroxymethyl self-crosslinking cation exchange resin containing a sulfonic acid structure, having the structure shown in Formula I: Formula I; in, Assuming the total amount of x, y, and z is 100 mol%, the total amount of x is 25-40 mol%, and the total amount of y is 10-25 mol%.

2. The method for preparing the sulfonic acid-containing hydroxymethyl self-crosslinking cation exchange resin according to claim 1, characterized in that, Includes the following steps: The monomer, initiator and organic solvent are mixed and subjected to solution polymerization-hydroxy self-crosslinking reaction to obtain the sulfonic acid-containing hydroxymethyl self-crosslinking cation exchange resin; The monomers are 2-acrylamido-2-methylpropanesulfonic acid, N-hydroxymethylacrylamide and methyl methacrylate, wherein the content of 2-acrylamido-2-methylpropanesulfonic acid is 25~40 mol and the content of N-hydroxymethylacrylamide is 10~25 mol.

3. The preparation method according to claim 2, characterized in that, The amount of the initiator is 0.2-1% of the total amount of the monomer.

4. The preparation method according to claim 2 or 3, characterized in that, The initiator includes at least one of benzoyl peroxide and azobisisobutyronitrile.

5. The preparation method according to claim 2, characterized in that, The organic solvent includes at least one of N,N-dimethylacetamide, N,N-dimethylformamide, and N-methylpyrrolidone.

6. The preparation method according to claim 2 or 5, characterized in that, The mass of the organic solvent is 2 to 6 times the total mass of the monomers.

7. The preparation method according to claim 2, 3 or 5, characterized in that, The solution polymerization-hydroxyl self-crosslinking reaction is carried out at a temperature of 70~90℃ for 1~2h.

8. The preparation method according to claim 7, characterized in that, The solution polymerization-hydroxy self-crosslinking reaction further includes: sequentially pulverizing, washing, and drying the self-crosslinking gel polymer obtained from the solution polymerization-hydroxy self-crosslinking reaction.

9. The preparation method according to claim 8, characterized in that, The detergent for washing includes at least one of ethanol and methanol.

10. The application of the sulfonic acid-containing hydroxymethyl self-crosslinking cation exchange resin according to claim 1 or the sulfonic acid-containing hydroxymethyl self-crosslinking cation exchange resin prepared by any one of claims 2 to 9 in environmental water treatment, new energy battery electrolytes, natural drug purification or oil extraction.

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