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CN-121975069-A - Saline-alkali soil modifier and preparation method thereof

CN121975069ACN 121975069 ACN121975069 ACN 121975069ACN-121975069-A

Abstract

The invention belongs to the technical field of saline-alkali soil improvement, and particularly relates to a saline-alkali soil modifier and a preparation method thereof. The preparation method of the saline-alkali soil modifier comprises the following steps of carrying out polymerization reaction on nonylphenol polyoxyethylene ether acrylic ester in a solvent under the action of an initiator, then adding acrylamide and acrylic acid, continuing the polymerization reaction, and finally adding a crosslinking monomer consisting of a diene sulfonic acid compound and a diene amino acid salt compound, and continuing the polymerization reaction to obtain the saline-alkali soil modifier. The diene amino acid salt compound and the diene sulfonic acid compound can effectively improve the crosslinking degree of the material, branched amino acid salt and sulfonic acid groups in the two monomers can be matched with a crosslinking system to form a network with proper pore diameters, the hydrophilic adsorptivity of the pore diameters of the network is improved, liquid can enter the material, and the poor liquid adsorption capacity caused by loose network structure and the liquid releasing capacity caused by collapse of the material at high temperature can be avoided.

Inventors

  • XU MENG
  • ZHOU XUAN
  • PENG ZHIHONG
  • GAO SHENGCHAO

Assignees

  • 中国农业科学院农业资源与农业区划研究所
  • 湖南省耕地与农业环境生态研究所
  • 盐碱地综合利用技术创新中心

Dates

Publication Date
20260505
Application Date
20260204

Claims (10)

  1. 1. A preparation method of a saline-alkali soil modifier is characterized by comprising the following steps of carrying out polymerization reaction on nonylphenol polyoxyethylene ether acrylate in a solvent under the action of an initiator, then adding acrylamide and acrylic acid, continuing the polymerization reaction, finally adding a crosslinking monomer, and continuing the polymerization reaction to obtain the saline-alkali soil modifier, wherein the crosslinking monomer consists of a diolefin sulfonic acid compound and a diolefin amino acid salt compound, and the chemical structure of the diolefin amino acid salt compound is as follows: ; The chemical structure of the diene sulfonic acid compound is as follows: 。
  2. 2. the preparation method of the saline-alkali soil improver according to claim 1, wherein the mass ratio of the nonylphenol polyoxyethylene ether acrylate, the acrylamide, the acrylic acid, the diolefin sulfonic acid compound and the diolefin amino acid salt compound is 2:2-3:10-12:0.002-0.004:0.003-0.006.
  3. 3. The method for preparing a saline-alkali soil conditioner according to claim 1, wherein the initiator is persulfate.
  4. 4. The method for preparing the saline-alkali soil conditioner according to claim 3, wherein when the polyoxyethylene nonylphenol acrylate is polymerized in a solvent under the action of an initiator, the mass of the initiator is 0.02% -0.03% of that of the polyoxyethylene nonylphenol acrylate, the polymerization temperature is 65-70 ℃ and the polymerization time is 1-2 hours.
  5. 5. The method for preparing a saline-alkali soil conditioner according to any one of claims 1 to 4, wherein an initiator is added when acrylamide and acrylic acid are added and polymerization is continued, the mass of the initiator is 0.02% -0.03% of the sum of the mass of the acrylamide and the mass of the acrylic acid, the temperature at which polymerization is continued is 65-70 ℃, and the time is 45-60 min.
  6. 6. The method for producing a modifier for saline-alkali soil according to any one of claims 1 to 4, wherein a crosslinking monomer is added, and an initiator is added when continuing the polymerization reaction, wherein the mass of the initiator is 0.02% to 0.03% of the sum of the mass of the diolefin sulfonic acid compound and the mass of the diolefin amino acid salt compound, and the temperature at which the polymerization reaction is continued is 65 to 70 ℃ for 30 to 50 minutes.
  7. 7. The method for preparing a saline-alkali soil conditioner according to any one of claims 1 to 4, wherein after the polymerization reaction is finished, the reaction product is kept stand for 2 to 3 hours, then washed with ethanol, dried and crushed, then washed with ethanol again, and dried to obtain the saline-alkali soil conditioner.
  8. 8. The method for preparing a saline-alkali soil conditioner according to any one of claims 1 to 4, wherein the dialkene amino acid salt compound is prepared by a michael addition reaction of sodium dimercaptosuccinate and N, N' -methylenebisacrylamide in a molar ratio of 1:2.
  9. 9. The method for preparing a modifier for saline-alkali soil according to any one of claims 1 to 4, wherein the diolefin sulfonic acid compound is prepared by mixing 1, 7-octadiene-3, 6-diol and 4- (chlorosulfonyl) benzoyl chloride in a molar ratio of 1:2, and then performing hydrolysis reaction.
  10. 10. A saline-alkali soil conditioner prepared by the method for preparing a saline-alkali soil conditioner according to any one of claims 1 to 9.

Description

Saline-alkali soil modifier and preparation method thereof Technical Field The invention belongs to the technical field of saline-alkali soil improvement, and particularly relates to a saline-alkali soil modifier and a preparation method thereof. Background Salinization of soil is two processes of salinization and alkalization of soil, and soil salinization refers to the process of gradually accumulating to surface soil through vertical or horizontal movement of capillaries of the soil under the actions of evaporation, transpiration and the like of salt rich in groundwater, surface water and rock matrix. Soil alkalization refers to the accumulation of water-soluble salts, typically neutral or near neutral salts, such as sodium sulfate, sodium chloride, and the like, on the soil surface and in the soil. Thus, salinized soil is primarily soil containing an excess of soluble salt ions. The saline-alkali soil has high pH, high salt content, relatively poor air and water permeability, very low fertilizer efficiency, influences the growth of crops, and the crops in severe saline-alkali soil areas can hardly survive. Land salinization essentially means that soluble salts are rearranged in the soil, and the salt content of the soil is accumulated on the surface layer in a large amount so that the content exceeds a normal value. The reasons for the accumulation of salt in the soil mainly comprise natural factors and artificial factors, wherein the natural factors used as internal factors mainly comprise climate, topography, soil vegetation, soil moisture change and the like, and the artificial factors used as external factors have serious influence on soil salinization, in particular to secondary salinization. The water-retaining saline-alkali soil modifier has the advantages that the molecular structure of the water-retaining saline-alkali soil modifier contains a large number of hydrophilic groups, the water molecules can freely enter the interior of the modifier molecule due to the special three-dimensional space network structure, the large number of hydrophilic groups on the molecule can be combined with the water molecules after ionization, and the large number of water molecules are absorbed through the effect of chemical adsorption, so that the large number of evaporation of water in soil is avoided, the time of the effective water content of the soil is prolonged, the salt content of the soil is diluted, and the growth of crops is promoted. However, the molecular network structure strength of the water-retention type saline-alkali soil modifier prepared at present is smaller, and the water-absorption and water-retention capacity is poor when the water-retention type saline-alkali soil modifier is used in an alkaline environment with the pH value of more than 8, so that the application range is limited. Disclosure of Invention Aiming at the problems, the invention provides a saline-alkali soil modifier and a preparation method thereof, which are used for solving the problem that the water absorption and water retention capacity of the existing water-retention saline-alkali soil modifier are poor when the existing water-retention saline-alkali soil modifier is used in an alkaline environment with the pH value of more than 8. In order to achieve the above purpose, the invention adopts the following technical scheme: A preparation method of a saline-alkali soil modifier comprises the following steps of carrying out polymerization reaction on nonylphenol polyoxyethylene ether acrylate in a solvent under the action of an initiator, then adding acrylamide and acrylic acid, continuing the polymerization reaction, finally adding a crosslinking monomer, and continuing the polymerization reaction to obtain the saline-alkali soil modifier, wherein the crosslinking monomer consists of a diene sulfonic acid compound and a diene amino acid salt compound, and the chemical structure of the diene amino acid salt compound is as follows: ; The chemical structure of the diene sulfonic acid compound is as follows: 。 Preferably, the mass ratio of the nonylphenol polyoxyethylene ether acrylate to the acrylamide to the acrylic acid to the diolefin sulfonic acid compound to the diolefin amino acid salt compound is 2:2-3:10-12:0.002-0.004:0.003-0.006. Preferably, the initiator is a persulfate. Preferably, when the polyoxyethylene nonylphenol acrylate is subjected to polymerization reaction in a solvent under the action of an initiator, the mass of the initiator is 0.02% -0.03% of that of the polyoxyethylene nonylphenol acrylate, the polymerization reaction temperature is 65-70 ℃, and the polymerization reaction time is 1-2 hours. Preferably, acrylamide and acrylic acid are added, and when the polymerization reaction is continued, an initiator is added, wherein the mass of the initiator is 0.02% -0.03% of the sum of the mass of the acrylamide and the mass of the acrylic acid, the temperature of the polymerization reaction is 65-70 ℃ a