Macroporous adsorption resin with high cycle stability and preparation method thereof

Abstract

The invention relates to the technical field of resin processing, and discloses macroporous adsorption resin with high cycle stability and a preparation method thereof.The macroporous adsorption resin is prepared from styrene, ethylene glycol dimethacrylate, trimethylolpropane triacrylate, a dispersing agent, a chelating type nanometer material, an initiator, an epoxy compound and a pore-foaming agent; the chelating nano material is prepared by performing surface modification on nano silicon dioxide through a silane coupling agent containing acrylate nitrile guanidine s-triazine, the chelating nano material contains acrylate groups, and the chelating nano material, monomer styrene, cross-linking agent ethylene glycol dimethacrylate and trimethylolpropane triacrylate can be polymerized through a suspension polymerization method, so that the chelating nano material is prepared. Adsorption resin microspheres embedded with inorganic particles are formed, the adsorption resin microspheres can be cross-linked with an epoxy compound, the macroporous adsorption resin is finally obtained through supercritical carbon dioxide treatment, the macroporous adsorption resin has high cycle stability and excellent mechanical strength, and the adsorption rate of copper ions is increased.

Description

Technical Field

[0001] This invention relates to the field of resin processing technology, and in particular to a macroporous adsorption resin with high cycle stability and its preparation method. Background Technology

[0002] Macroporous adsorption resins are novel high-molecular polymer adsorption materials that are insoluble in acids, alkalis, and organic solvents. They possess stable physicochemical properties and exhibit a porous, three-dimensional network structure, large specific surface area, and fast adsorption rate. Compared with adsorption materials such as activated carbon, zeolite molecular sieves, clay, and silica gel, they have a larger adsorption capacity, more stable performance after regeneration, lower operating costs, can be reused, and have a longer service life. They are widely used in product separation and purification, industrial decolorization, food processing, and environmental protection.

[0003] Traditional macroporous adsorption resins face severe structural degradation during dynamic adsorption. While highly cross-linked resins have high mechanical strength, their insufficient macroporous structure development leads to slow adsorption rates. Low-cross-linked resins, despite their large pore size, are prone to pore collapse and particle breakage after repeated swelling and shrinkage. Existing reinforcement techniques, such as adding glass fibers, can clog pores, while core-shell structure fabrication processes are complex and costly. Especially in moving bed continuous adsorption devices, the resin must withstand high-speed fluid impacts and frequent regenerative thermal stress. Conventional materials struggle to balance macroporous structure and cycle stability, resulting in shortened operating cycles and soaring replacement costs for industrial equipment. Summary of the Invention

[0004] This invention provides a macroporous adsorption resin with high cycling stability and its preparation method. Based on the current status of traditional macroporous adsorption resins, this invention modifies the macroporous adsorption resin by introducing chelating nanomaterials. Through the synergistic effect of the chelating nanomaterials and post-crosslinking, it balances macroporous structure, cycling stability and mechanical strength to meet the requirements of moving bed continuous adsorption devices. On the other hand, it can improve the adsorption rate of copper ions by the macroporous adsorption resin.

[0005] A macroporous adsorption resin with high cycle stability comprises the following raw materials in parts by weight:

[0006] 40-55 parts styrene;

[0007] 10-20 parts ethylene glycol dimethacrylate;

[0008] 5-15 parts of trimethylolpropane triacrylate;

[0009] 4-6 parts dispersant;

[0010] 2-6 parts of chelated nanomaterials;

[0011] 0.8-1.2 parts initiator;

[0012] 3-5 parts epoxy compound;

[0013] 30-50 parts pore-forming agent;

[0014] Among them, chelated nanomaterials are prepared by surface modification of nano-silica using a silane coupling agent containing acrylate nitrile guanidine triazine.

[0015] Furthermore, the preparation method of the silane coupling agent containing acrylate nitrile guanidine triazine is as follows:

[0016] One molar equivalent of cyanuric chloride and one molar equivalent of dicyandiamide undergo a substitution reaction, which then reacts with dichloro intermediate a to obtain the product.

[0017] One molar equivalent of dichloro intermediate a and one molar equivalent of hydroxyacrylate undergo a substitution reaction to give monochloro intermediate b;

[0018] One molar equivalent of monochloro intermediate b reacts with one molar equivalent of aminosilane coupling agent to obtain a silane coupling agent containing acrylate nitrile guanidine triazine.

[0019] Furthermore, the hydroxyacrylate is hydroxyethyl acrylate or hydroxyethyl methacrylate.

[0020] Further, the aminosilane coupling agent is any one of N-aminoethyl-3-aminopropyltriethoxysilane, N-aminoethyl-3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, or 3-aminopropyltrimethoxysilane.

[0021] Furthermore, the dispersant is any one of polyvinyl alcohol, gelatin, or Span-80.

[0022] Furthermore, the initiator is benzoyl peroxide or azobisisobutyronitrile.

[0023] Furthermore, the epoxy compound is epichlorohydrin or bisphenol A diglycidyl ether.

[0024] Furthermore, the pore-forming agent is any one or two of toluene and liquid paraffin.

[0025] A method for preparing a macroporous adsorption resin with high cycling stability includes the following steps:

[0026] Step 1: Prepare the aqueous phase by adding the dispersant to deionized water, heating to 85-95℃, stirring until homogeneous, and then cooling to 30-45℃.

[0027] Step 2: Prepare the oil phase. Mix styrene, ethylene glycol dimethacrylate, and trimethylolpropane triacrylate evenly. Add the initiator and stir until evenly mixed. Add the pore-forming agent and stir until evenly mixed. Then add the chelated nanomaterials and ultrasonically disperse them evenly.

[0028] Step 3: Prepare the crude macroporous adsorption resin product. Under argon protection, pour the prepared oil phase into the aqueous phase, raise the temperature to 65-75℃, and after suspension polymerization for 5-7 hours, adsorption resin microspheres are formed. Then, add an epoxy compound for crosslinking, raise the temperature to 70-90℃, and react for 3-5 hours to form the crude macroporous adsorption resin product.

[0029] Step 4: Pore structure locking. Add supercritical carbon dioxide to dry the crude macroporous adsorption resin product, and remove the residual porogen at 8-12 MPa to fix the interconnected macropores and obtain macroporous adsorption resin.

[0030] Furthermore, the pore size of the macroporous adsorption resin is between 50-500 nm.

[0031] Beneficial effects:

[0032] (1) In this invention, chelated nanomaterials are prepared by surface modification of nano-silica with silane coupling agent containing acrylate, nitrile guanidine and triazine. Acrylate, nitrile guanidine and triazine are introduced on the surface of nano-silica. The nitrile guanidine and triazine improve the chelation of copper ions and increase the adsorption rate.

[0033] (2) The chelated nanomaterial prepared by the present invention contains acrylate groups, which can form inorganic particle embedded adsorption resin microspheres by suspension polymerization with monomer styrene, crosslinking agent dimethacrylate and trimethylolpropane triacrylate. The adsorption resin microspheres can crosslink with epoxy compounds. Finally, after treatment with supercritical carbon dioxide, macroporous adsorption resin is obtained.

[0034] (3) The macroporous adsorption resin prepared by the present invention through the synergistic effect of chelating nanomaterials and post-crosslinking has a macroporous structure, high cycle stability and excellent mechanical strength, which can meet the high-speed operation conditions of moving bed and improve the adsorption rate of copper ions. Experiments show that after 50 adsorption-regeneration cycles, the particle integrity rate is >98%, the pore structure collapse rate is <5%, the saturated adsorption capacity retention rate is >95%, the interconnected macropore porosity of the macroporous adsorption resin is >65%, and the adsorption rate of copper ions is >95%. Detailed Implementation

[0035] Experimental Example 1:

[0036] The preparation method of chelated nanomaterials is as follows:

[0037] One molar equivalent of cyanuric chloride and one molar equivalent of dicyandiamide undergo a substitution reaction to give dichloro intermediate a;

[0038] One molar equivalent of dichloro intermediate a and one molar equivalent of hydroxyethyl acrylate undergo a substitution reaction to give monochloro intermediate b;

[0039] One molar equivalent of monochloro intermediate b reacts with one molar equivalent of N-aminoethyl-3-aminopropyltriethoxysilane to give a silane coupling agent containing acrylate nitrile guanidine triazine.

[0040] chelated nanomaterials were obtained by surface modification of nano-silica using a silane coupling agent containing acrylate nitrile guanidine triazine.

[0041] Experimental Example 2:

[0042] The specific preparation steps for chelated nanomaterials are as follows:

[0043] Step 1: Add 1.8g of cyanuric chloride to 30mL of acetone, stir thoroughly to dissolve, and stir in an ice bath for 10min to lower the temperature to 5℃. Slowly add 20mL of a solution containing 0.8g of dicyandiamide, stir for 2h, then add a 10% sodium carbonate solution to adjust the pH to about 6. After reacting for 4h, cool in ice water for 10min, filter, wash with acetone, and dry to obtain dichloro intermediate a.

[0044] Step 2: Add 2.4g of dichloro intermediate a and 1.1mL of hydroxyethyl acrylate to 40mL of acetone, add 10% sodium carbonate solution dropwise, adjust the pH to about 7, raise the temperature to 40℃, react for 5h, let stand to precipitate, filter, wash with acetone, dry, and obtain monochloro intermediate b.

[0045] Step 3: Add 3g of monochloro intermediate b to 50mL of toluene, mix thoroughly, add 2.6mL of N-aminoethyl-3-aminopropyltriethoxysilane, add 10% sodium carbonate solution dropwise, adjust the pH to about 7, raise the temperature to 95℃, react for 5h, cool to room temperature, let stand to precipitate, filter, wash with toluene, dry, and obtain silane coupling agent containing acrylate nitrile guanidine triazine;

[0046] Step 4: Add 2g of nano-silica (particle size 10-30nm) to 50mL of anhydrous ethanol, sonicate for 30min, introduce nitrogen gas, add 5mL of silane coupling agent containing acrylate nitrile guanidine triazine under uniform stirring, heat to reflux, react for 6h, cool to room temperature, centrifuge, dry to obtain chelated nanomaterials.

[0047] Example 1:

[0048] A macroporous adsorption resin with high cycle stability comprises the following raw materials in parts by weight:

[0049] 50 parts styrene;

[0050] 15 parts ethylene glycol dimethacrylate;

[0051] 10 parts of trimethylolpropane triacrylate;

[0052] 5 parts polyvinyl alcohol;

[0053] Two portions of chelated nanomaterials (prepared in Example 2);

[0054] 1 part benzoyl peroxide;

[0055] 4 parts epichlorohydrin;

[0056] 40 parts toluene;

[0057] A macroporous adsorption resin with high cycle stability is prepared by the following steps:

[0058] Step 1: Prepare the aqueous phase by adding polyvinyl alcohol to 500 parts by weight of deionized water, heating to 90°C, stirring until homogeneous, and then cooling to 35°C.

[0059] Step 2: Prepare the oil phase. Mix styrene, ethylene glycol dimethacrylate, and trimethylolpropane triacrylate evenly. Add benzoyl peroxide and stir until evenly mixed. Add toluene and stir until evenly mixed. Then add chelated nanomaterials and ultrasonically disperse them evenly.

[0060] Step 3: Prepare the crude macroporous adsorption resin product. Under argon protection, pour the prepared oil phase into the aqueous phase, raise the temperature to 70℃, and after suspending polymerization for 6 hours, adsorption resin microspheres are formed. Then, add 20 parts by weight of ethanol solution containing epichlorohydrin to crosslink the resin. Raise the temperature to 80℃ and react for 4 hours to form the crude macroporous adsorption resin product.

[0061] Step 4: Pore structure locking. Add supercritical carbon dioxide to dry the crude macroporous adsorption resin product, and remove residual toluene at 10 MPa to fix the interconnected macropores and obtain macroporous adsorption resin.

[0062] Example 2:

[0063] A macroporous adsorption resin with high cycle stability comprises the following raw materials in parts by weight:

[0064] 50 parts styrene;

[0065] 15 parts ethylene glycol dimethacrylate;

[0066] 10 parts of trimethylolpropane triacrylate;

[0067] 5 parts polyvinyl alcohol;

[0068] Four portions of chelated nanomaterials (prepared in Experimental Example 2);

[0069] 1 part benzoyl peroxide;

[0070] 4 parts epichlorohydrin;

[0071] 40 parts toluene;

[0072] A macroporous adsorption resin with high cycle stability is prepared by the following steps:

[0073] Step 1: Prepare the aqueous phase by adding polyvinyl alcohol to 500 parts by weight of deionized water, heating to 90°C, stirring until homogeneous, and then cooling to 35°C.

[0074] Step 2: Prepare the oil phase. Mix styrene, ethylene glycol dimethacrylate, and trimethylolpropane triacrylate evenly. Add benzoyl peroxide and stir until evenly mixed. Add toluene and stir until evenly mixed. Then add chelated nanomaterials and ultrasonically disperse them evenly.

[0075] Step 3: Prepare the crude macroporous adsorption resin product. Under argon protection, pour the prepared oil phase into the aqueous phase, raise the temperature to 70℃, and after suspending polymerization for 6 hours, adsorption resin microspheres are formed. Then, add 20 parts by weight of ethanol solution containing epichlorohydrin to crosslink the resin. Raise the temperature to 80℃ and react for 4 hours to form the crude macroporous adsorption resin product.

[0076] Step 4: Pore structure locking. Add supercritical carbon dioxide to dry the crude macroporous adsorption resin product, and remove residual toluene at 10 MPa to fix the interconnected macropores and obtain macroporous adsorption resin.

[0077] Example 3:

[0078] A macroporous adsorption resin with high cycle stability comprises the following raw materials in parts by weight:

[0079] 50 parts styrene;

[0080] 15 parts ethylene glycol dimethacrylate;

[0081] 10 parts of trimethylolpropane triacrylate;

[0082] 5 parts polyvinyl alcohol;

[0083] Six portions of chelated nanomaterials (prepared in Experimental Example 2);

[0084] 1 part benzoyl peroxide;

[0085] 4 parts epichlorohydrin;

[0086] 40 parts toluene;

[0087] A macroporous adsorption resin with high cycle stability is prepared by the following steps:

[0088] Step 1: Prepare the aqueous phase by adding polyvinyl alcohol to 500 parts by weight of deionized water, heating to 90°C, stirring until homogeneous, and then cooling to 35°C.

[0089] Step 2: Prepare the oil phase. Mix styrene, ethylene glycol dimethacrylate, and trimethylolpropane triacrylate evenly. Add benzoyl peroxide and stir until evenly mixed. Add toluene and stir until evenly mixed. Then add chelated nanomaterials and ultrasonically disperse them evenly.

[0090] Step 3: Prepare the crude macroporous adsorption resin product. Under argon protection, pour the prepared oil phase into the aqueous phase, raise the temperature to 70℃, and after suspending polymerization for 6 hours, adsorption resin microspheres are formed. Then, add 20 parts by weight of ethanol solution containing epichlorohydrin to crosslink the resin. Raise the temperature to 80℃ and react for 4 hours to form the crude macroporous adsorption resin product.

[0091] Step 4: Pore structure locking. Add supercritical carbon dioxide to dry the crude macroporous adsorption resin product, and remove residual toluene at 10 MPa to fix the interconnected macropores and obtain macroporous adsorption resin.

[0092] Comparative Example 1:

[0093] A macroporous adsorption resin comprises the following raw materials in parts by weight:

[0094] 50 parts styrene;

[0095] 15 parts ethylene glycol dimethacrylate;

[0096] 10 parts of trimethylolpropane triacrylate;

[0097] 4-6 parts polyvinyl alcohol;

[0098] Four modified nanomaterials;

[0099] 1 part benzoyl peroxide;

[0100] 4 parts epichlorohydrin;

[0101] 40 parts toluene;

[0102] A macroporous adsorption resin, the specific preparation method of which includes the following steps:

[0103] Step 1: Prepare the aqueous phase by adding polyvinyl alcohol to 500 parts by weight of deionized water, heating to 90°C, stirring until homogeneous, and then cooling to 35°C.

[0104] Step 2: Preparation of modified nanomaterials. 2g of nano-silica was added to a mixed solution prepared by 25mL of anhydrous ethanol and 25mL of deionized water. After ultrasonic dispersion for 30min, 5mL of 3-(methacryloyloxy)propyltrimethoxysilane was added. The mixture was heated to reflux and reacted for 6h. After cooling to room temperature, the mixture was centrifuged and dried to obtain the modified nanomaterials.

[0105] Step 3: Prepare the oil phase. Mix styrene, ethylene glycol dimethacrylate, and trimethylolpropane triacrylate evenly. Add benzoyl peroxide and stir until evenly mixed. Add toluene and stir until evenly mixed. Then add the modified nanomaterials and disperse them evenly by ultrasonication.

[0106] Step 4: Prepare the crude macroporous adsorption resin product. Under argon protection, pour the prepared oil phase into the aqueous phase, raise the temperature to 70℃, and after suspension polymerization for 6 hours, the crude macroporous adsorption resin product is formed.

[0107] Step 5: Pore structure locking. Add supercritical carbon dioxide to dry the crude macroporous adsorption resin product, and remove residual toluene at 10 MPa to fix the interconnected macropores and obtain macroporous adsorption resin.

[0108] Performance testing:

[0109] I. Testing of Mechanical Strength and Pore Structure Parameters

[0110] The mechanical strength of the macroporous adsorption resin particles in Examples 1-3 and Comparative Example 1 was tested using an automatic particle strength tester. An average of 5 tests were performed, and the average value was calculated. The specific surface area, average pore size, and interconnected macropore porosimetry of the macroporous adsorption resin were tested using a fully automatic mercury porosimeter. The test results are shown in Table 1.

[0111] Table 1 Test results of mechanical strength and pore structure parameters

[0112] No. Mechanical strength (N / particle) Specific surface area (m 2 / g) Average pore diameter (nm) Through-pore porosity (%) Example 1 13.3 691.7 301.2 67.3 Example 2 14.3 711.2 290.1 66.2 Example 3 13.9 700.4 295.4 66.8 Comparative Example 1 8.4 683.2 281.6 50.9

[0113] II. Adsorption Experiment and Regeneration Adsorption Experiment

[0114] Adsorption experiment: 0.1 g of the macroporous adsorption resin prepared in Examples 1-3 and Comparative Example 1 was added to 50 mL of 0.5 mg / mL copper sulfate solution. The adsorption was carried out at room temperature and the solution was shaken at a shaking rate of 120 r / min. The concentration of residual copper ions after adsorption was detected by ultraviolet spectrophotometry.

[0115] The adsorption capacity and removal rate of copper ions by macroporous adsorption resin are calculated using the formula: Q = V(C 初 -C 终 ) / m, where Q is the equilibrium adsorption capacity of copper ions, V is the volume of the copper ion-containing solution, and C 初 C represents the initial concentration of copper ions in the solution. 终 R represents the final concentration of copper ions after adsorption, m represents the mass of the macroporous adsorption resin, and the adsorption rate formula is: R = [(C 初 -C 终 ) / C 初 ×100%;

[0116] Regeneration adsorption experiment: After the initial adsorption equilibrium, the macroporous adsorption resins prepared in Examples 1-3 and Comparative Example 1 were separated from the copper sulfate solution and soaked overnight in 0.1 mol / L nitric acid solution. After deion washing, the metal ion concentration was measured to be 0. After drying, a cyclic adsorption experiment was performed under the same experimental conditions to determine the saturated adsorption capacity retention rate. The cycle was repeated 50 times.

[0117] The formula for calculating the saturated adsorption retention rate is: B = (Q 初 / Q 终 )×100%, Q 初 Q represents the initial saturated adsorption capacity. 终 The final saturated adsorption capacity after recycling is given; the particle integrity rate of the macroporous adsorption resin is calculated as follows: [mass (or number) of intact particles after recycling / initial mass (or number) of intact particles] × 100%; the pore structure collapse rate of the macroporous adsorption resin is calculated as follows: [(initial specific surface area - specific surface area after recycling) / initial specific surface area] × 100%;

[0118] The test results are shown in Table 2:

[0119] Table 2 Test results of adsorption and regeneration adsorption experiments

[0120] No. Adsorption rate (%) Retention rate of saturated adsorption capacity after 50 adsorption-regeneration cycles (%) Retention rate of particle integrity after 50 adsorption-regeneration cycles (%) Collapse rate of pore structure after 50 adsorption-regeneration cycles (%) Example 1 96.2 95.1 98.1 4.8 Example 2 97.5 95.6 98.7 4.2 Example 3 96.8 95.4 98.5 4.5 Comparative Example 1 70.2 75.9 72.2 13.6

Claims

1. A macroporous adsorption resin with high cycle stability, characterized in that, Including the following parts by weight of raw materials: 40-55 parts styrene; 10-20 parts ethylene glycol dimethacrylate; 5-15 parts of trimethylolpropane triacrylate; 4-6 parts dispersant; 2-6 parts of chelated nanomaterials; 0.8-1.2 parts initiator; 3-5 parts epoxy compound; 30-50 parts pore-forming agent; Among them, chelated nanomaterials are prepared by surface modification of nano-silica using a silane coupling agent containing acrylate nitrile guanidine triazine.

2. The high-cycle-stability macroporous adsorption resin according to claim 1, characterized in that, The preparation method of the silane coupling agent containing acrylate nitrile guanidine triazine is as follows: One molar equivalent of cyanuric chloride and one molar equivalent of dicyandiamide undergo a substitution reaction, which then reacts with dichloro intermediate a to obtain the product. One molar equivalent of dichloro intermediate a and one molar equivalent of hydroxyacrylate undergo a substitution reaction to give monochloro intermediate b; One molar equivalent of monochloro intermediate b reacts with one molar equivalent of aminosilane coupling agent to obtain a silane coupling agent containing acrylate nitrile guanidine triazine.

3. The high-cycle-stability macroporous adsorption resin according to claim 2, characterized in that, The hydroxyacrylate is hydroxyethyl acrylate or hydroxyethyl methacrylate.

4. The high-cycle-stability macroporous adsorption resin according to claim 2, characterized in that, The aminosilane coupling agent is any one of N-aminoethyl-3-aminopropyltriethoxysilane, N-aminoethyl-3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, or 3-aminopropyltrimethoxysilane.

5. The high-cycle-stability macroporous adsorption resin according to claim 1, characterized in that, The dispersant is any one of polyvinyl alcohol, gelatin, or Span-80.

6. The high-cycle-stability macroporous adsorption resin according to claim 1, characterized in that, The initiator is benzoyl peroxide or azobisisobutyronitrile.

7. The high-cycle-stability macroporous adsorption resin according to claim 1, characterized in that, The epoxy compound is epichlorohydrin or bisphenol A diglycidyl ether.

8. The high-cycle-stability macroporous adsorption resin according to claim 1, characterized in that, The pore-forming agent is any one or two of toluene and liquid paraffin.

9. A method for preparing a high-cycle-stability macroporous adsorption resin as described in claim 1, characterized in that, Includes the following steps: Step 1: Prepare the aqueous phase by adding the dispersant to deionized water, heating to 85-95℃, stirring until homogeneous, and then cooling to 30-45℃. Step 2: Prepare the oil phase. Mix styrene, ethylene glycol dimethacrylate, and trimethylolpropane triacrylate evenly. Add the initiator and stir until evenly mixed. Add the pore-forming agent and stir until evenly mixed. Then add the chelated nanomaterials and ultrasonically disperse them evenly. Step 3: Prepare the crude macroporous adsorption resin product. Under argon protection, pour the prepared oil phase into the aqueous phase, raise the temperature to 65-75℃, and after suspension polymerization for 5-7 hours, adsorption resin microspheres are formed. Then, add an epoxy compound for crosslinking, raise the temperature to 70-90℃, and react for 3-5 hours to form the crude macroporous adsorption resin product. Step 4: Pore structure locking. Add supercritical carbon dioxide to dry the crude macroporous adsorption resin product, and remove the residual porogen at 8-12 MPa to fix the interconnected macropores and obtain macroporous adsorption resin.

10. The high-cycle-stability macroporous adsorption resin according to claim 1, characterized in that, The pore size of the macroporous adsorption resin is between 50 and 500 nm.