A method for preparing a natural-synthetic copolymer saline-alkali land conditioner
By preparing a copolymer of modified natural macromolecular carboxymethyl cellulose and biochar, a soil conditioner for saline-alkali land was prepared, which solved the problems of difficult degradation and environmental unfriendliness of artificially synthesized conditioners, and achieved both soil improvement and environmental friendliness for saline-alkali land.
Patent Information
- Application Number
- CN202411877437.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-19
- Publication Date
- 2025-11-14
- Estimated Expiration
- 2044-12-19
AI Technical Summary
Existing synthetic soil conditioners are difficult to degrade and are environmentally unfriendly when used to improve saline-alkali land, while natural macromolecular conditioners are not very effective in application.
Natural macromolecular carboxymethyl cellulose was used to modify acrylic polymers, and biochar was added to the copolymer network to prepare a natural-synthetic copolymer saline-alkali land conditioner. The copolymer precursor mixed dispersion was formed through pyrolysis, stirring and mixing steps, and the conditioner was finally obtained.
The prepared soil conditioner has good water absorption and salt resistance, can effectively improve soil pore structure, increase soil organic matter content, and improve the physical and chemical properties of saline-alkali soil. The method is environmentally friendly and mild.
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Figure CN119736095B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of saline-alkali land conditioners, and more particularly to a method for preparing a natural-synthetic copolymer saline-alkali land conditioner. Background Technology
[0002] Currently, the most widely used soil conditioners are synthetic soil conditioners. These are mainly artificially synthesized high-molecular-weight organic polymers, such as polyacrylamide and polyvinyl alcohol. They have significant soil-improving effects, but most of them are difficult to degrade and are not environmentally friendly.
[0003] Natural macromolecules typically possess excellent water absorption and sustainability, and are widely distributed in nature at low cost. Modifying artificially synthesized soil conditioners using natural macromolecules can effectively alleviate these problems. Their main functions are to improve soil structure and physicochemical properties, enhance soil fertility, mitigate soil erosion, and improve the salinity of arid soils. Summary of the Invention
[0004] In view of this, the present invention provides a method for preparing a natural-synthetic copolymer saline-alkali land conditioner.
[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:
[0006] A method for preparing a natural-synthetic copolymer saline-alkali land conditioner, wherein the amount of material taken is in parts by weight, includes the following steps:
[0007] Step 1: Preparation of Cotton Stalk Biochar
[0008] Cotton stalk powder and potassium bicarbonate were added to a quartz ceramic boat, placed in a tube furnace, and pyrolyzed under an argon atmosphere. After natural cooling, the ash was removed by washing with deionized water and dried to obtain cotton stalk biochar.
[0009] Step 2: Preparation of the carboxymethyl cellulose free radical initiation system
[0010] Carboxymethyl cellulose was dissolved in deionized water and stirred under heating conditions. Under nitrogen protection, ammonium persulfate solution was added while stirring to continue the reaction, resulting in a carboxymethyl cellulose free radical initiation system solution.
[0011] Step 3: Preparation of copolymer precursor mixed dispersion
[0012] In a sealed container purged with nitrogen, sodium hydroxide solution and acrylic acid were added and stirred at 0 degrees Celsius until the solution became clear and transparent. Then acrylamide was added and stirred at room temperature until the acrylamide was completely dissolved. Next, the cotton straw biochar and N,N′-methylenebisacrylamide solution were added and stirred at room temperature to disperse the biochar evenly in the solution, thus obtaining the precursor mixture dispersion of the copolymer.
[0013] Step 4: Preparation of natural-synthetic copolymer saline-alkali land conditioner
[0014] Under nitrogen protection and heating conditions, the copolymer precursor mixture prepared in the third step is added to the carboxymethyl cellulose free radical initiation system solution prepared in the second step while stirring. The mixture is stirred continuously to ensure thorough and uniform mixing. The system temperature is then increased, and the reaction is continued with stirring. The product after the reaction is dried to constant weight and pulverized to obtain the natural-synthetic copolymer saline-alkali land conditioner.
[0015] Preferably, in the first step, the cotton stalk powder is 3-5 parts of dried cotton stalk powder that has passed through an 80-mesh sieve, and the amount of potassium bicarbonate added is 6-10 parts.
[0016] Preferably, in the first step, the pyrolysis method is to heat the temperature to 400-600°C at a heating rate of 5°C / min and maintain it for 2-4 hours.
[0017] Preferably, in the first step, the drying condition is 60°C.
[0018] Preferably, in the second step, the amount of carboxymethyl cellulose added is 3-6 parts, the amount of deionized water added is 100-200 parts, the heating condition is 60-80℃, and the stirring time is 2-4 hours.
[0019] Preferably, in the second step, the amount of ammonium persulfate solution added is 2 to 3 parts, the mass fraction is 12 to 15%, and the reaction time is 30 to 60 minutes.
[0020] Preferably, in the third step, the amount of sodium hydroxide solution added is 5-12 parts, with a mass fraction of 10-25%; the amount of acrylic acid added is 25-40 parts, and the amount of acrylamide added is 60-75 parts.
[0021] Preferably, in the third step, the amount of cotton straw biochar prepared in the first step is 1 to 5 parts, the amount of N,N′-methylenebisacrylamide solution is 3 to 5 parts with a mass fraction of 1 to 3%, and the stirring time at room temperature is 10 to 30 minutes.
[0022] Preferably, in the fourth step, the heating condition is 50°C, and the continuous stirring time is 60-90 minutes.
[0023] Preferably, in the fourth step, the system temperature is raised to 65-80°C, the reaction time is continuously stirred for 2-3 hours, the drying temperature is 60°C, and the material is pulverized through an 80-mesh sieve.
[0024] The present invention achieves the following technical effects compared to the prior art:
[0025] (1) In this invention, natural macromolecular carboxymethyl cellulose is used to modify acrylic polymers, giving them good water absorption and salt resistance;
[0026] (2) Adding biochar to the copolymer network can effectively improve soil porosity and promote the formation of soil aggregates, while also increasing soil organic matter content.
[0027] (3) The method of the present invention has mild reaction conditions and uses green and environmentally friendly materials, which can improve the physical and chemical properties of saline-alkali soil. Attached Figure Description
[0028] Figure 1 This is a SEM image of the natural-synthetic copolymer saline-alkali land conditioner prepared according to the method of this invention.
[0029] Figure 2 This is a simultaneous thermal analysis diagram of the natural-synthetic copolymer saline-alkali land conditioner prepared according to the method of this invention.
[0030] Figure 3 The diagram shows the improvement effect of the natural-synthetic copolymer saline-alkali land conditioner prepared according to the method of this invention. Detailed Implementation
[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0032] like Figure 1-3 As shown, this invention discloses a method for preparing a natural-synthetic copolymer saline-alkali land conditioner, comprising the following steps:
[0033] Step 1: Preparation of Cotton Stalk Biochar
[0034] Take 3-5 parts of dried cotton stalk powder that has passed through an 80-mesh sieve and 6-10 parts of potassium bicarbonate and add them to a quartz ceramic boat. Place the boat in a tube furnace and heat it to 400-600°C at a heating rate of 5°C / min under an argon atmosphere. Maintain the temperature for 2-4 hours. After natural cooling, wash the boat with deionized water to remove ash and dry it at 60°C to obtain cotton stalk biochar for later use.
[0035] Step 2: Preparation of the carboxymethyl cellulose free radical initiation system
[0036] Take 3-6 parts of carboxymethyl cellulose, add 100-200 parts of deionized water, and stir at 60-80℃ for 2-4 hours to dissolve it. Probe with nitrogen gas, and while stirring, add 2-3 parts of a 12-15% (w / w) ammonium persulfate solution, and continue the reaction for 30-60 minutes to obtain a carboxymethyl cellulose free radical initiation system solution for later use.
[0037] Step 3: Preparation of copolymer precursor mixed dispersion
[0038] In a sealed autoclave purged with nitrogen, add 5-12 parts of a 10-25% sodium hydroxide solution and 25-40 parts of acrylic acid. Stir at 0°C until the solution is clear and transparent. Then add 60-75 parts of acrylamide and stir at room temperature until the acrylamide is completely dissolved. Next, add 1-5 parts of the cotton straw biochar prepared in the first step and 3-5 parts of a 1-3% N,N′-methylenebisacrylamide solution. Stir at room temperature for 10-30 minutes to uniformly disperse the biochar in the solution, thus obtaining the precursor dispersion of the copolymer, which is ready for use.
[0039] Step 4: Preparation of natural-synthetic copolymer saline-alkali land conditioner
[0040] Under nitrogen protection and at 50°C, the copolymer precursor mixture prepared in the third step is added to the carboxymethyl cellulose free radical initiation system solution prepared in the second step while stirring. The mixture is stirred continuously for 60-90 minutes to ensure thorough mixing. The system temperature is then raised to 65-80°C, and the reaction is continued with stirring for 2-3 hours. The product is dried at 60°C to constant weight and then pulverized through an 80-mesh sieve to obtain the natural-synthetic copolymer saline-alkali soil conditioner.
[0041] Example 1
[0042] Step 1: Preparation of Cotton Stalk Biochar
[0043] Take 3 parts of dried cotton stalk powder that has passed through an 80-mesh sieve and 6 parts of potassium bicarbonate and add them to a quartz ceramic boat. Place the boat in a tube furnace and heat it to 400°C at a heating rate of 5°C / min under an argon atmosphere. Hold the temperature for 2 hours. After natural cooling, wash the boat with deionized water to remove ash and dry it at 60°C to obtain cotton stalk biochar for later use.
[0044] Step 2: Preparation of the carboxymethyl cellulose free radical initiation system
[0045] Take 3 parts of carboxymethyl cellulose, add 100 parts of deionized water, and stir at 60°C for 2 hours to dissolve it; purge with nitrogen gas, and while stirring, add 2 parts of 12% ammonium persulfate solution, and continue the reaction for 30 minutes to obtain a carboxymethyl cellulose free radical initiation system solution for later use.
[0046] Step 3: Preparation of copolymer precursor mixed dispersion
[0047] In a sealed autoclave purged with nitrogen, add 5 parts of a 10% sodium hydroxide solution and 25 parts of acrylic acid. Stir at 0°C until the solution is clear and transparent. Then add 75 parts of acrylamide and stir at room temperature until the acrylamide is completely dissolved. Next, add 1 part of the cotton straw biochar prepared in the first step and 3 parts of a 1% N,N′-methylenebisacrylamide solution. Stir at room temperature for 10 minutes to uniformly disperse the biochar in the solution, thus obtaining the precursor dispersion of the copolymer, which is ready for use.
[0048] Step 4: Preparation of natural-synthetic copolymer saline-alkali land conditioner
[0049] Under nitrogen protection and at 50°C, the copolymer precursor mixture prepared in the third step was added to the carboxymethyl cellulose free radical initiation system solution prepared in the second step while stirring. The mixture was stirred continuously for 60 minutes to ensure thorough mixing. The system temperature was then raised to 65°C and the reaction was continued for 2 hours. The product was dried at 60°C to constant weight and then pulverized through an 80-mesh sieve to obtain the natural-synthetic copolymer saline-alkali land conditioner.
[0050] Take 5 parts of natural-synthetic copolymer saline-alkali soil conditioner and 1000 parts of air-dried saline-alkali soil, mix them evenly, fill them into a soil column to a height of 30cm, add deionized water, and stop adding water when the wetting front reaches 30cm. After the soil column is placed for one week, measure the pH, electrical conductivity and total water-soluble salt content of the blank treatment and the improved soil samples respectively.
[0051] Example 2
[0052] Step 1: Preparation of Cotton Stalk Biochar
[0053] Take 3 parts of dried cotton stalk powder that has passed through an 80-mesh sieve and 7 parts of potassium bicarbonate and add them to a quartz ceramic boat. Place the boat in a tube furnace and heat it to 400°C at a heating rate of 5°C / min under an argon atmosphere. Hold the temperature for 2.5 hours. After natural cooling, wash the boat with deionized water to remove ash and dry it at 60°C to obtain cotton stalk biochar for later use.
[0054] Step 2: Preparation of the carboxymethyl cellulose free radical initiation system
[0055] Take 4 parts of carboxymethyl cellulose, add 100 parts of deionized water, and stir at 65°C for 3 hours to dissolve it; purge with nitrogen gas, and while stirring, add 2 parts of 12% ammonium persulfate solution, and continue the reaction for 45 minutes to obtain a carboxymethyl cellulose free radical initiation system solution for later use.
[0056] Step 3: Preparation of copolymer precursor mixed dispersion
[0057] In a sealed autoclave purged with nitrogen, add 6 parts of a 12% sodium hydroxide solution and 30 parts of acrylic acid. Stir at 0°C until the solution is clear and transparent. Then add 70 parts of acrylamide and stir at room temperature until the acrylamide is completely dissolved. Next, add 2 parts of the cotton straw biochar prepared in the first step and 3 parts of a 2% N,N′-methylenebisacrylamide solution. Stir at room temperature for 15 minutes to uniformly disperse the biochar in the solution, thus obtaining the precursor dispersion of the copolymer, which is ready for use.
[0058] Step 4: Preparation of natural-synthetic copolymer saline-alkali land conditioner
[0059] Under nitrogen protection and at 50°C, the copolymer precursor mixture prepared in the third step was added to the carboxymethyl cellulose free radical initiation system solution prepared in the second step while stirring. The mixture was stirred continuously for 70 min to ensure thorough mixing. The system temperature was then raised to 70°C and the reaction was continued with stirring for 2.5 h. The product was dried at 60°C to constant weight and then pulverized through an 80-mesh sieve to obtain the natural-synthetic copolymer saline-alkali soil conditioner.
[0060] Take 7 parts of natural-synthetic copolymer saline-alkali soil conditioner and 1000 parts of air-dried saline-alkali soil, mix them evenly, fill them into a soil column to a height of 30cm, add deionized water, and stop adding water when the wetting front reaches 30cm. After the soil column is placed for one week, measure the pH, electrical conductivity and total water-soluble salt content of the blank treatment and the improved soil samples respectively.
[0061] Example 3
[0062] Step 1: Preparation of Cotton Stalk Biochar
[0063] Take 4 parts of dried cotton stalk powder that has passed through an 80-mesh sieve and 8 parts of potassium bicarbonate and add them to a quartz ceramic boat. Place the boat in a tube furnace and heat it to 500°C at a heating rate of 5°C / min under an argon atmosphere. Hold the temperature for 3 hours. After natural cooling, wash the boat with deionized water to remove ash and dry it at 60°C to obtain cotton stalk biochar for later use.
[0064] Step 2: Preparation of the carboxymethyl cellulose free radical initiation system
[0065] Take 5 parts of carboxymethyl cellulose, add 200 parts of deionized water, stir at 70°C for 3 hours to dissolve it, purge with nitrogen for protection, add 3 parts of 14% ammonium persulfate solution while stirring, continue the reaction for 45 minutes to obtain the carboxymethyl cellulose free radical initiation system solution for later use.
[0066] Step 3: Preparation of copolymer precursor mixed dispersion
[0067] In a sealed autoclave purged with nitrogen, 7 parts of a 13% sodium hydroxide solution and 35 parts of acrylic acid were added, and the mixture was stirred at 0°C until the solution was clear and transparent. Then, 65 parts of acrylamide were added, and the mixture was stirred at room temperature until the acrylamide was completely dissolved. Next, 3 parts of the cotton straw biochar prepared in the first step and 3.5 parts of a 2% N,N′-methylenebisacrylamide solution were added, and the mixture was stirred at room temperature for 20 minutes to ensure that the biochar was uniformly dispersed in the solution, thus obtaining the precursor mixture dispersion of the copolymer, which was then set aside for later use.
[0068] Step 4: Preparation of natural-synthetic copolymer saline-alkali land conditioner
[0069] Under nitrogen protection and at 50°C, the copolymer precursor mixture prepared in the third step was added to the carboxymethyl cellulose free radical initiation system solution prepared in the second step while stirring. The mixture was stirred continuously for 80 minutes to ensure thorough mixing. The system temperature was then raised to 70°C and the reaction was continued for 2.5 hours. The product was dried at 60°C to constant weight and then pulverized through an 80-mesh sieve to obtain the natural-synthetic copolymer saline-alkali soil conditioner.
[0070] Take 12 parts of natural-synthetic copolymer saline-alkali soil conditioner and 1000 parts of air-dried saline-alkali soil, mix them evenly, fill them into a soil column to a height of 30cm, add deionized water, and stop adding water when the wetting front reaches 30cm. After the soil column is placed for one week, measure the pH, electrical conductivity and total water-soluble salt content of the blank treatment and the improved soil samples respectively.
[0071] Example 4
[0072] Step 1: Preparation of Cotton Stalk Biochar
[0073] Take 4 parts of dried cotton stalk powder that has passed through an 80-mesh sieve and 8 parts of potassium bicarbonate and add them to a quartz ceramic boat. Place the boat in a tube furnace and heat it to 500°C at a heating rate of 5°C / min under an argon atmosphere. Hold the temperature for 3 hours. After natural cooling, wash the boat with deionized water to remove ash and dry it at 60°C to obtain cotton stalk biochar for later use.
[0074] Step 2: Preparation of the carboxymethyl cellulose free radical initiation system
[0075] Take 5 parts of carboxymethyl cellulose, add 200 parts of deionized water, stir at 80℃ for 3 hours to dissolve it, purge with nitrogen for protection, add 3 parts of 14% ammonium persulfate solution while stirring, continue the reaction for 50 minutes to obtain the carboxymethyl cellulose free radical initiation system solution for later use.
[0076] Step 3: Preparation of copolymer precursor mixed dispersion
[0077] In a sealed autoclave purged with nitrogen, add 10 parts of a 20% sodium hydroxide solution and 40 parts of acrylic acid. Stir at 0°C until the solution is clear and transparent. Then add 60 parts of acrylamide and stir at room temperature until the acrylamide is completely dissolved. Next, add 4 parts of the cotton straw biochar prepared in the first step and 4 parts of a 3% N,N′-methylenebisacrylamide solution. Stir at room temperature for 30 minutes to uniformly disperse the biochar in the solution, thus obtaining the precursor dispersion of the copolymer, which is ready for use.
[0078] Step 4: Preparation of natural-synthetic copolymer saline-alkali land conditioner
[0079] Under nitrogen protection and at 50°C, the copolymer precursor mixture prepared in the third step was added to the carboxymethyl cellulose free radical initiation system solution prepared in the second step while stirring. The mixture was stirred continuously for 90 minutes to ensure thorough mixing. The system temperature was then raised to 75°C and the reaction was continued with stirring for 2.5 hours. The product was dried at 60°C to constant weight and then pulverized through an 80-mesh sieve to obtain the natural-synthetic copolymer saline-alkali soil conditioner.
[0080] Take 10 parts of natural-synthetic copolymer saline-alkali soil conditioner and 1000 parts of air-dried saline-alkali soil, mix them evenly, fill them into a soil column to a height of 30cm, add deionized water, and stop adding water when the wetting front reaches 30cm. After the soil column is placed for one week, measure the pH, electrical conductivity and total water-soluble salt content of the blank treatment and the improved soil samples respectively.
[0081] Example 5
[0082] Step 1: Preparation of Cotton Stalk Biochar
[0083] Take 5 parts of dried cotton stalk powder that has passed through an 80-mesh sieve and 10 parts of potassium bicarbonate and add them to a quartz ceramic boat. Place the boat in a tube furnace and heat it to 600°C at a heating rate of 5°C / min under an argon atmosphere. Hold the temperature for 4 hours. After natural cooling, wash the boat with deionized water to remove ash and dry it at 60°C to obtain cotton stalk biochar for later use.
[0084] Step 2: Preparation of the carboxymethyl cellulose free radical initiation system
[0085] Take 6 parts of carboxymethyl cellulose, add 200 parts of deionized water, stir at 80℃ for 4 hours to dissolve it, purge with nitrogen for protection, add 3 parts of 15% ammonium persulfate solution while stirring, continue the reaction for 60 minutes to obtain the carboxymethyl cellulose free radical initiation system solution for later use.
[0086] Step 3: Preparation of copolymer precursor mixed dispersion
[0087] In a sealed autoclave purged with nitrogen, 12 parts of a 25% sodium hydroxide solution and 40 parts of acrylic acid were added, and the mixture was stirred at 0°C until the solution was clear and transparent. Then, 60 parts of acrylamide were added, and the mixture was stirred at room temperature until the acrylamide was completely dissolved. Next, 5 parts of the cotton straw biochar prepared in the first step and 5 parts of a 3% N,N′-methylenebisacrylamide solution were added, and the mixture was stirred at room temperature for 30 minutes to uniformly disperse the biochar in the solution, thus obtaining the precursor mixture dispersion of the copolymer, which was then set aside for later use.
[0088] Step 4: Preparation of natural-synthetic copolymer saline-alkali land conditioner
[0089] Under nitrogen protection and at 50°C, the copolymer precursor mixture prepared in the third step was added to the carboxymethyl cellulose free radical initiation system solution prepared in the second step while stirring. The mixture was stirred continuously for 90 minutes to ensure thorough mixing. The system temperature was then raised to 80°C and the reaction was continued for 3 hours. The product was dried at 60°C to constant weight and then pulverized through an 80-mesh sieve to obtain the natural-synthetic copolymer saline-alkali soil conditioner.
[0090] Take 15 parts of natural-synthetic copolymer saline-alkali soil conditioner and 1000 parts of air-dried saline-alkali soil, mix them evenly, fill them into a soil column to a height of 30cm, add deionized water, and stop adding water when the wetting front reaches 30cm. After the soil column is placed for one week, measure the pH, electrical conductivity and total water-soluble salt content of the blank treatment and the improved soil samples respectively.
[0091] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the technical scope of the present invention. Therefore, any minor modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.
Claims
1. A method for preparing a natural-synthetic copolymer saline-alkali land conditioner, characterized in that, The quantity taken is in parts by weight, and includes the following steps: Step 1: Preparation of Cotton Stalk Biochar Cotton stalk powder and potassium bicarbonate were added to a quartz ceramic boat, placed in a tube furnace, and pyrolyzed under an argon atmosphere. After natural cooling, the ash was removed by washing with deionized water and dried to obtain cotton stalk biochar. Step 2: Preparation of the carboxymethyl cellulose free radical initiation system Carboxymethyl cellulose was dissolved in deionized water and stirred under heating conditions. Under nitrogen protection, ammonium persulfate solution was added while stirring to continue the reaction, resulting in a carboxymethyl cellulose free radical initiation system solution. Step 3: Preparation of copolymer precursor mixed dispersion In a sealed container purged with nitrogen, sodium hydroxide solution and acrylic acid were added and stirred at 0 degrees Celsius until the solution became clear and transparent. Then acrylamide was added and stirred at room temperature until the acrylamide was completely dissolved. Next, the cotton straw biochar and N,N′-methylenebisacrylamide solution were added and stirred at room temperature to disperse the biochar evenly in the solution, thus obtaining the precursor mixture dispersion of the copolymer. Step 4: Preparation of natural-synthetic copolymer saline-alkali land conditioner Under nitrogen protection and heating conditions, the copolymer precursor mixture prepared in the third step is added to the carboxymethyl cellulose free radical initiation system solution prepared in the second step while stirring. The mixture is stirred continuously to ensure thorough and uniform mixing. The system temperature is then increased, and the reaction is continued with stirring. The product after the reaction is dried to constant weight and pulverized to obtain the natural-synthetic copolymer saline-alkali land conditioner.
2. The method for preparing a natural-synthetic copolymer saline-alkali land conditioner according to claim 1, characterized in that, In the first step, the cotton stalk powder is 3-5 parts of dried cotton stalk powder that has passed through an 80-mesh sieve, and the amount of potassium bicarbonate added is 6-10 parts.
3. The method for preparing a natural-synthetic copolymer saline-alkali land conditioner according to claim 1, characterized in that, In the first step, the pyrolysis method involves heating the temperature to 400–600°C at a heating rate of 5°C / min and maintaining it for 2–4 hours.
4. The method for preparing a natural-synthetic copolymer saline-alkali land conditioner according to claim 1, characterized in that, In the first step, the drying condition is 60°C.
5. The method for preparing a natural-synthetic copolymer saline-alkali land conditioner according to claim 1, characterized in that, In the second step, the amount of carboxymethyl cellulose added is 3 to 6 parts, the amount of deionized water added is 100 to 200 parts, the heating condition is 60 to 80°C, and the stirring time is 2 to 4 hours.
6. The method for preparing a natural-synthetic copolymer saline-alkali land conditioner according to claim 1, characterized in that, In the second step, the amount of ammonium persulfate solution added is 2 to 3 parts, the mass fraction is 12 to 15%, and the reaction time is 30 to 60 minutes.
7. The method for preparing a natural-synthetic copolymer saline-alkali land conditioner according to claim 1, characterized in that, In the third step, the amount of sodium hydroxide solution added is 5-12 parts, with a mass fraction of 10-25%; the amount of acrylic acid added is 25-40 parts; and the amount of acrylamide added is 60-75 parts.
8. The method for preparing a natural-synthetic copolymer saline-alkali land conditioner according to claim 1, characterized in that, In the third step, the amount of cotton stalk biochar prepared in the first step is 1 to 5 parts, the amount of N,N′-methylenebisacrylamide solution is 3 to 5 parts with a mass fraction of 1 to 3%, and the stirring time at room temperature is 10 to 30 minutes.
9. The method for preparing a natural-synthetic copolymer saline-alkali land conditioner according to claim 1, characterized in that, In the fourth step, the heating condition is 50°C, and the stirring time is 60-90 minutes.
10. The method for preparing a natural-synthetic copolymer saline-alkali land conditioner according to claim 1, characterized in that, In the fourth step, the system temperature is raised to 65-80℃, the reaction is continuously stirred for 2-3 hours, the drying temperature is 60℃, and the powder is pulverized through an 80-mesh sieve.
Citation Information
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