Synthesis method of quinary humic acid drought-resistant water-retaining agent

Abstract

The invention provides a synthesis method of a quinary humic acid drought-resistant water-retaining agent. The synthesis method comprises the following steps: dissolving sodium humate in water to obtain a sodium humate aqueous solution; adding acrylic acid and acrylamide into the sodium humate aqueous solution, and fully stirring to obtain a solution A; dropwise adding a NaOH aqueous solution into the solution A, fully stirring, then adding ammonium persulfate, then adding N, N '-methylene bisacrylamide, heating in a water bath to 75 DEG C, maintaining the temperature of 75 DEG C, reacting until the mixture forms a sticky substance, and stopping stirring when stirring cannot be carried out; and keeping the temperature of the sticky mass for 2-3 hours, taking out the product, cleaning with distilled water, putting into a dry culture dish, cutting into small blocks, drying, taking out, and grinding to obtain the quinary humic acid drought-resistant water-retaining agent. When the method provided by the invention is used for halogenation catalytic reaction, the reaction system is closed, the reaction temperature is moderate, and no three wastes are discharged in the preparation process.

Description

Technical Field

[0001] The present application belongs to the technical field of drought-resistant and water-retaining agents, and relates to a method for synthesizing a five-element humic acid drought-resistant and water-retaining agent. Background Art

[0002] Water retaining agents are a class of chemicals used to retain moisture in the soil. They absorb and slowly release water, thereby increasing the soil's water retention capacity.

[0003] Water retaining agents can effectively improve the soil's water retention capacity, reduce water evaporation loss, and provide a stable water source for plants; because water retaining agents can slowly release water, they can reduce the number of irrigation times and save water resources; water retaining agents can improve the soil structure, increase soil aeration and permeability, and promote the growth of plant roots; water retaining agents can provide plants with stable moisture, which is beneficial to plant growth and increases plant growth rate.

[0004] However, current water-retaining agents face major challenges: Synthetic water-retaining agents are relatively expensive, increasing agricultural production costs; some water-retaining agents can have adverse environmental impacts, such as soil and water pollution caused by harmful substances produced during degradation; and their use is subject to certain restrictions, such as being unsuitable for specific soil types like sandy and saline-alkali lands. While water-retaining agents can improve soil water retention in the short term, their long-term effectiveness remains unclear.

[0005] Synthetic water-retaining agents have obvious advantages in improving soil water retention capacity, reducing irrigation times, improving soil structure and increasing plant growth rate. However, they also have disadvantages such as high cost, environmental impact, usage restrictions and unclear long-term effects. Summary of the Invention

[0006] The technical problem to be solved by this application is that existing synthetic water-retaining agents have disadvantages such as high cost, environmental impact, usage restrictions and unclear long-term effects.

[0007] In order to solve the above problems, the present application provides a method for synthesizing a five-element humic acid drought-resistant water-retaining agent, comprising: dissolving sodium humate in water to obtain a sodium humate aqueous solution; Adding acrylic acid and acrylamide to the sodium humate aqueous solution and stirring thoroughly to obtain solution A; Add NaOH aqueous solution dropwise to the solution A and stir thoroughly, then add ammonium persulfate and then add N,N'-methylenebisacrylamide, heat in a water bath to 75°C, and maintain the temperature at 75°C until the mixture forms a sticky mass and cannot be stirred; The sticky mass is kept warm for 2-3 hours, then the product is taken out, washed with distilled water, placed in a dry culture dish, cut into small pieces, dried, taken out and ground to obtain a five-element humic acid drought-resistant water-retaining agent.

[0008] This application uses sodium humate as a raw material, and sequentially adds acrylic acid as a first copolymer monomer, polyacrylamide as a second copolymer unit, acrylamide as a third copolymer monomer, alkali (NaOH), an initiator, and a cross-linking agent MBA to carry out a free radical polymerization reaction in an aqueous solution to obtain a five-element humic acid drought-resistant water-retaining agent product.

[0009] Furthermore, the volume ratio of the mass of the sodium humate to the water is 50g~100g:300mL~500mL.

[0010] Furthermore, the mass ratio of the sodium humate solution, the acrylic acid, and the acrylamide is (350-600):(70-80):(10-20).

[0011] Furthermore, the concentration of the NaOH aqueous solution is 0.2 g / mL.

[0012] Furthermore, the amount of the NaOH aqueous solution added is 55 mL.

[0013] Furthermore, the mass ratio of the sodium humate solution: acrylic acid: acrylamide: NaOH aqueous solution: ammonium sulfate: N,N'-methylenebisacrylamide is (350-600):(70-80):(10-20):11:(3-5):(1-2).

[0014] Furthermore, the drying temperature is 60°C and the drying time is 6 to 8 hours.

[0015] The above-mentioned synthesis method provided in this application is specifically as follows: S1. Weigh 50-100 g of sodium humate, add 300-500 mL of deionized water, and mechanically stir at room temperature until the sodium humate is substantially dissolved to obtain a sodium humate solution. S2. Then, 70-80 g of acrylic acid and 10-20 g of acrylamide were added to the sodium humate solution and stirred for 10 minutes to obtain solution A. S3. Add 55 mL of 0.2 g / mL NaOH aqueous solution dropwise to the above solution A, stir thoroughly, then add 3-5 g of ammonium persulfate, and then add 1-2 g of N,N'-methylenebisacrylamide. Heat in a water bath to 75°C, and maintain this temperature until the mixture forms a sticky mass and cannot be stirred; S4. Keep the sticky mass warm for 2-3 hours, then take out the product, wash it with distilled water, put it into a dry culture dish, cut it into small pieces of 5-10 mm, put it into a 60°C oven to dry (6-8 hours), take it out and grind it to obtain the five-element humic acid drought-resistant water-retaining agent.

[0016] The technical effects of this application are: 1. The present invention uses sodium humate as a raw material, sequentially adds acrylic acid as the first comonomer, polyacrylamide as the second comonomer, acrylamide as the third comonomer, alkali (NaOH), an initiator, and a crosslinking agent MBA, and conducts a free radical polymerization reaction in an aqueous solution to obtain a five-component humic acid drought-resistant water-retaining agent product.

[0017] 2. The present application provides a method for synthesizing a quaternary humic acid drought-resistant and water-retaining agent, which has a safe reaction system, low production cost, simple synthesis process, and is easy to industrialize; 2. The method provided in this application is used to carry out halogenation catalytic reaction. Since the reaction system is closed and the reaction temperature is moderate, no three wastes are discharged during the preparation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is the full XPS spectrum of A1; Figure 2 is the C 1s spectrum of A1; Figure 3 is the O 1s spectrum of A1; Figure 4 This is the full XPS spectrum of A2; Figure 5 is the C 1s spectrum of A2; Figure 6 is the O 1s spectrum of A2; Figure 7 This is the full XPS spectrum of A3; Figure 8 is the C 1s spectrum of A3; Figure 9 is the O 1s spectrum of A3; Figure 10 is the K 2p spectrum of A3; Figure 11 It is the full XPS spectrum of A4; Figure 12 is the C 1s spectrum of A4; Figure 13 This is the O 1s spectrum of A4; Figure 14 is the K 2p spectrum of A4; Figure 15 is the N 1s spectrum of A4; Figure 16This is the S 2p spectrum of A4. DETAILED DESCRIPTION

[0019] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0020] Example 1 Weigh 60 g of sodium humate into a 1 L three-necked flask, then add 300 mL of deionized water. Stir mechanically at room temperature until the mixture is essentially dissolved. Then, add 79.5 g of acrylic acid and 15 g of acrylamide, stirring continuously for 10 minutes. Add 55 mL of a 0.2 g / mL NaOH solution dropwise, stirring thoroughly. Then, add 4.2 g of ammonium persulfate and 1.6 g of N,N'-methylenebisacrylamide. Heat in a water bath to 75°C and maintain this temperature until the mixture forms a sticky mass and cannot be stirred. Incubate for 2 hours. Remove the product, rinse with distilled water, place it in a dry Petri dish, cut it into 5-10 mm pieces, and dry it in a 60°C oven for 6-8 hours. Grind it, bag it, and store it for later use. This is designated A1.

[0021] Example 2 Weigh 60 g of sodium humate into a 1 L three-necked flask, then add 300 mL of deionized water. Stir mechanically at room temperature until the mixture is essentially dissolved. Then, add 79.5 g of acrylic acid, 15 g of acrylamide, and 10 g of 2-acrylamido-2-methylpropanesulfonic acid. Stir continuously for 10 minutes. Add 55 mL of a 0.2 g / mL aqueous NaOH solution dropwise and stir thoroughly. Then, add 4.2 g of ammonium persulfate and 1.6 g of N,N'-methylenebisacrylamide. Heat in a water bath to 75°C and maintain this temperature until the mixture forms a sticky mass and cannot be stirred. Incubate for 2 hours. Remove the product, rinse with distilled water, place it in a dry Petri dish, cut it into 5-10 mm pieces, and dry it in a 60°C oven for 6-8 hours. Grind it, bag it, and store it for later use. This is designated A2.

[0022] Example 3 Weigh 60 g of potassium humate into a 1 L three-necked flask, then add 300 mL of deionized water. Stir mechanically at room temperature until substantially dissolved. Then, add 79.5 g of acrylic acid and 15 g of acrylamide, stirring continuously for 10 minutes. Add 55 mL of a 0.2 g / mL aqueous solution of KOH dropwise, stirring thoroughly. Then, add 4.2 g of ammonium persulfate and 1.6 g of N,N'-methylenebisacrylamide. Heat in a water bath to 75°C and maintain this temperature until the mixture forms a sticky mass and cannot be stirred. Incubate for 2 hours. Remove the product, rinse with distilled water, place it in a dry Petri dish, cut it into 5-10 mm pieces, and dry it in a 60°C oven for 6-8 hours. Grind it, bag it, and store it for later use. This is designated A3.

[0023] Example 4 Weigh 60 g of potassium humate into a 1 L three-necked flask, then add 300 mL of deionized water. Stir mechanically at room temperature until substantially dissolved. Then, add 79.5 g of acrylic acid, 15 g of acrylamide, and 10 g of 2-acrylamido-2-methylpropanesulfonic acid. Stir continuously for 10 minutes. Add 55 mL of a 0.2 g / mL aqueous solution of KOH dropwise and stir thoroughly. Then, add 4.2 g of ammonium persulfate and 1.6 g of N,N'-methylenebisacrylamide. Heat in a water bath to 75°C and maintain this temperature until the mixture forms a sticky mass and cannot be stirred. Incubate for 2 hours. Remove the product, rinse with distilled water, place it in a dry Petri dish, cut it into 5-10 mm pieces, and dry it in a 60°C oven for 6-8 hours. Grind it, bag it, and store it for later use. This is designated A4.

[0024] A1 was subjected to XPS analysis, and the results are shown in Table 1.

[0025] Table 1 Element binding energy and chemical composition of A1 a Binding energy (eV), the value in parentheses is the atomic percentage (at%). According to the data in Table 10, it can be seen that the theoretical molecular formula of A1 is: C 70.60 O 22.89 N 1.57 S 1.14 B 0.30 Si 2.69 Na 0.81 , molecular weight 1370.1171, mass percentage: C% = 61.88%, O% = 26.73%, Na% = 1.36%. A1 contains a small amount of S, which comes from the raw material ammonium persulfate.

[0026] Depend on Figure 1It can be seen that, apart from the elements reported in Table 10, A1 does not contain other impurity elements.

[0027] Depend on Figure 2 It can be seen that the peak with binding energy at 284.8 eV represents the carbon atoms on the alkyl chain (hybridization mode sp 3 The peak with a binding energy of 286.3 eV represents the carbon atom of the CO bond, while the peak with a binding energy of 288.9 eV represents the carbon atom of the carboxyl group. The molar ratio is alkyl carbon:CO carbon:carboxyl carbon = 67.13:17.30:15.57.

[0028] Depend on Figure 3 It can be seen that the peak at the binding energy of 531.6 eV represents the oxygen on the C-O bond, while the broad peak at 532.2 eV represents the oxygen on the C=O bond, and the small peak at 533.2 eV represents the oxygen of the A1 hydroxyl group or the hydroxyl oxygen of adsorbed water.

[0029] A2 was subjected to XPS analysis, and the results are shown in Table 2.

[0030] Table 2 Element binding energy and chemical composition of A2 a Binding energy (eV), the value in parentheses is the atomic percentage (at%). According to the data in Table 2, it can be seen that the theoretical molecular formula of A2 is: C 70.24 O 20.76 N 1.48 S 1.01 Si 5.60 Na 0.91 , molecular weight is 1407.0827, mass percentage: C% = 59.95%, O% = 23.60%, Na % = 1.48%.

[0031] Depend on Figure 4 It can be seen that A2 does not contain other impurity elements except the elements reported in Table 11.

[0032] Depend on Figure 5 It can be seen that the peak with binding energy at 284.9 eV represents the carbon atoms on the alkyl chain (hybridization mode sp 3 The peak with a binding energy of 285.5 eV represents the carbon atom in a CO bond, the peak with a binding energy of 287.0 eV represents the carbon atom in a CN bond, and the peak with a binding energy of 288.7 eV represents the carbon atom in a carboxyl group. The molar ratio is alkyl carbon: CO carbon: CN carbon: carboxyl carbon = 23.55:38.90:8.37:29.18.

[0033] Depend on Figure 6 It can be seen that the broad peak with a binding energy of 532.3 eV represents the oxygen on the C=O bond, and the small peak at 533.6 eV represents the oxygen of the A2 hydroxyl group or the hydroxyl oxygen of adsorbed water.

[0034] A3 was subjected to XPS analysis, and the results are shown in Table 3.

[0035] Table 3 Element binding energy and chemical composition of A3 a Binding energy (eV), the value in parentheses is the atomic percentage (at%). According to the data in Table 3, we can see that: The experimental molecular formula of A3 is: C 52.23 O 25.42 N 1.18 Si 7.77 Na 0.25 K 13.16 , molecular weight is 1789.0969, mass percentage: C% = 35.06%, O% = 22.73%, Na% = 0.32%, K% = 28.76%.

[0036] Depend on Figure 7 It can be seen that A3 does not contain other impurity elements except the elements reported in Table 3.

[0037] Depend on Figure 8 It can be seen that the peak with binding energy at 284.6 eV represents the carbon atoms on the alkyl chain (hybridization mode sp 3 The peak with a binding energy of 285.7 eV represents the carbon atom of the CO bond, while the peak with a binding energy of 288.6 eV represents the carbon atom of the carboxyl group. The molar ratio is alkyl carbon:CO carbon:carboxyl carbon = 71.42:14.26:14.31.

[0038] Depend on Figure 9 It can be seen that the peak with a binding energy of 531.3 eV represents the oxygen of the CO bond, the broad peak with a binding energy of 531.7 eV represents the oxygen on the C=O bond, and the small peak at 532.7 eV represents the oxygen of the A3 hydroxyl group or the hydroxyl oxygen of adsorbed water.

[0039] Depend on Figure 10 It can be seen that the peak of binding energy at 295.7 eV represents K 2p 1 / 2 The photoelectron binding energy peak at 292.8 eV represents K 2p 3 / 2 photoelectrons, indicating that the potassium in A3 is in the form of K + exists in the form of .

[0040] A4 was subjected to XPS analysis, and the results are shown in Table 4.

[0041] Table 4 Element binding energy and chemical composition of A4 a Binding energy (eV), the value in parentheses is the atomic percentage (at%). According to the data in Table 4, we can see that: The experimental molecular formula of A4 is: C 60.04 O 19.24 N 1.17 S 0.63 Si 3.62 Na 0.17 K 15.12 , molecular weight is 1762.296, mass percentage: C% = 40.91%, O% = 17.46%, Na% = 0.22%, K% = 33.54%.

[0042] Depend on Figure 11 It can be seen that A4 does not contain other impurity elements except the elements reported in Table 4.

[0043] Depend on Figure 12 It can be seen that the peak with binding energy at 284.7 eV represents the carbon atoms on the alkyl chain (hybridization mode sp 3 The peak with a binding energy of 285.9 eV represents the carbon atom of the CO bond, while the peak with a binding energy of 288.7 eV represents the carbon atom of the carboxyl group. The molar ratio is alkyl carbon:CO carbon:carboxyl carbon = 62.91:19.99:17.10.

[0044] Depend on Figure 13 It can be seen that the broad peak with a binding energy of 531.8 eV represents the oxygen on the C=O bond, and the peak at 533.2 eV represents the oxygen of the A4 hydroxyl group or the hydroxyl oxygen of adsorbed water.

[0045] Depend on Figure 14 It can be seen that the peak of binding energy at 295.7 eV represents K 2p 1 / 2 The photoelectron binding energy peak at 293.0 eV represents K 2p 3 / 2 photoelectrons, indicating that the potassium in A4 is in the form of K + exists in the form of .

[0046] Depend on Figure 15 It can be seen that the N 1s spectrum of A4 contains one component: the peak at 399.7 eV represents the -NH- group, which originates from the synthetic raw material acrylamide.

[0047] Depend on Figure 16 It can be seen that the S 2p spectrum of A4 contains two components: the peak at 167.8 eV represents SO4 2-and S in the sulfonic acid group, the peak at 168.8 eV represents S2O8 2- The S peak of elemental state or metal sulfide is below 167.0 eV.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for synthesizing a five-element humic acid drought-resistant water-retaining agent, characterized in that: include: dissolving sodium humate in water to obtain a sodium humate aqueous solution; Adding acrylic acid and acrylamide to the sodium humate aqueous solution and stirring thoroughly to obtain solution A; Add NaOH aqueous solution dropwise to the solution A and stir thoroughly, then add ammonium persulfate and then add N,N'-methylenebisacrylamide, heat in a water bath to 75°C, and maintain the temperature at 75°C until the mixture forms a sticky mass and cannot be stirred; The sticky mass is kept warm for 2-3 hours, then the product is taken out, washed with distilled water, placed in a dry culture dish, cut into small pieces, dried, taken out and ground to obtain a five-element humic acid drought-resistant water-retaining agent.

2. The method for synthesizing the five-element humic acid drought-resistant water-retaining agent according to claim 1, characterized in that: In the sodium humate aqueous solution, the volume ratio of the mass of the sodium humate to the water is 50g~100g:300mL~500mL.

3. The method for synthesizing the five-element humic acid drought-resistant water-retaining agent according to claim 1, characterized in that: The mass ratio of the sodium humate solution, the acrylic acid, and the acrylamide is (350-600):(70-80):(10-20).

4. The method for synthesizing the five-element humic acid drought-resistant water-retaining agent according to claim 1, characterized in that: The concentration of the NaOH aqueous solution is 0.2 g / mL.

5. The method for synthesizing the five-element humic acid drought-resistant water-retaining agent according to claim 4, characterized in that: The amount of the NaOH aqueous solution added was 55 mL.

6. The method for synthesizing the five-element humic acid drought-resistant water-retaining agent according to claim 4, characterized in that: The mass ratio of the sodium humate solution: acrylic acid: acrylamide: NaOH aqueous solution: ammonium sulfate: N,N'-methylenebisacrylamide is (350-600):(70-80):(10-20):11:(3-5):(1-2).

7. The method for synthesizing the five-element humic acid drought-resistant and water-retaining agent according to claim 1, characterized in that: The drying temperature is 60°C and the drying time is 6 to 8 hours.

8. The method for synthesizing the five-element humic acid drought-resistant water-retaining agent according to claim 1, characterized in that: Specifically: S1. Weigh 50-100 g of sodium humate, add 300-500 mL of deionized water, and mechanically stir at room temperature until the sodium humate is substantially dissolved to obtain a sodium humate solution. S2. Then, 70-80 g of acrylic acid and 10-20 g of acrylamide were added to the sodium humate solution and stirred for 10 minutes to obtain solution A. S3. Add 55 mL of 0.2 g / mL NaOH aqueous solution dropwise to the above solution A, stir thoroughly, then add 3-5 g of ammonium persulfate, and then add 1-2 g of N,N'-methylenebisacrylamide. Heat in a water bath to 75°C, and maintain this temperature until the mixture forms a sticky mass and cannot be stirred; S4. Keep the sticky mass warm for 2-3 hours, then take out the product, wash it with distilled water, put it into a dry culture dish, cut it into small pieces of 5-10 mm, put it into a 60°C oven to dry (6-8 hours), take it out and grind it to obtain the five-element humic acid drought-resistant water-retaining agent.

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