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CN-121974756-A - Sustained-release composite material, preparation method and application thereof in potassium sulfate potash fertilizer

CN121974756ACN 121974756 ACN121974756 ACN 121974756ACN-121974756-A

Abstract

The invention relates to the technical field of fertilizers, and discloses a slow-release composite material, a preparation method and application thereof in potassium sulfate potash fertilizers. Epoxy resin modified bentonite is prepared by improving the epoxy vanillin, aldehyde modified bentonite and 1, 3-bis (3-aminopropyl) tetramethyl disiloxane, and is compounded with a biological polyurethane prepolymer, and then amino silicone oil and polyether amine are adopted for curing, and an inorganic material bentonite is introduced and a dynamic Schiff base bond is constructed, so that the slow-release composite material for the fertilizer, which is stable in structure and environment-friendly, is finally prepared, can be used as a coating material to be applied to potassium sulfate fertilizer, and realizes slow release of the potassium fertilizer.

Inventors

  • LIU DONGQIU
  • QU ZHI
  • ZHANG YUHANG

Assignees

  • 广东米高化工有限公司

Dates

Publication Date
20260505
Application Date
20260203

Claims (10)

  1. 1. The preparation method of the slow-release composite material is characterized by comprising the following steps of: Step (1), mixing aldehyde modified bentonite and dioxane, performing ultrasonic dispersion, adding 1, 3-bis (3-aminopropyl) tetramethyl disiloxane and acetic acid, reacting, adding epoxidized vanillin after the reaction is finished, continuing the reaction, cooling after the reaction is finished, and performing rotary evaporation to obtain epoxy resin modified bentonite; Step (2), mixing polycaprolactone dihydric alcohol and isophorone diisocyanate, adding dibutyl tin dilaurate, regulating the viscosity, reacting, cooling after the reaction is finished, adding castor oil, continuing the reaction, adding tartaric acid after the reaction is finished, and reacting again to obtain the bio-based polyurethane prepolymer after the reaction is finished; Mixing the bio-based polyurethane prepolymer, the epoxy resin modified bentonite, the amino silicone oil and the polyether amine to obtain the slow-release composite material.
  2. 2. The method for preparing a sustained-release composite material according to claim 1, wherein in the step (1), the aldehyde modified bentonite comprises the following steps: Mixing alkaline calcium bentonite and cyclohexane, performing ultrasonic dispersion, dropwise adding a p-aldehyde benzoic acid mixed solution, reacting after the dropwise adding is finished, performing suction filtration, washing and drying after the reaction is finished to obtain aldehyde modified bentonite.
  3. 3. The preparation method of the slow-release composite material according to claim 2, wherein in the step (1), when preparing the aldehyde modified bentonite, the p-aldehyde benzoic acid mixed solution is prepared by mixing p-aldehyde benzoic acid, ethanol and N, N-dimethylformamide according to a mass ratio of 0.5:1:9-10, wherein the ratio of alkaline calcium bentonite to cyclohexane to p-aldehyde benzoic acid is 1g to 20mL to 0.5-1g, and the reaction condition is that stirring reaction is carried out for 2-5h at a temperature of 60-70 ℃.
  4. 4. The method for preparing a sustained-release composite according to claim 1, wherein in the step (1), the epoxidized vanillin is prepared by the steps of: Mixing vanillin, tetrabutylammonium bromide and epichlorohydrin, reacting, cooling after the reaction is finished, dropwise adding a sodium hydroxide aqueous solution, stirring for continuous reaction after the dropwise adding is finished, and purifying after the reaction is finished to obtain the epoxidized vanillin.
  5. 5. The method for preparing the slow-release composite material according to claim 4, wherein in the step (1), when the epoxidized vanillin is prepared, the molar ratio of vanillin to tetrabutylammonium bromide to epichlorohydrin to sodium hydroxide is 1:0.1:5-10:2, the reaction condition is that the reaction is carried out for 2 hours at the temperature of 80 ℃, the concentration of the sodium hydroxide aqueous solution is 1-5mol/L, the dropwise addition condition is that the dropwise addition is carried out for 10-20 minutes at the temperature of 0-5 ℃, and the continuous reaction condition is that the stirring is carried out at the temperature of 0-5 ℃ for 2-5 hours.
  6. 6. The method for preparing the sustained-release composite material according to claim 1, wherein in the step (1), aldehyde modified bentonite, dioxane, 1, 3-bis (3-aminopropyl) tetramethyl disiloxane, acetic acid and epoxidized vanillin are mixed in a ratio of 5g to 80-150mL to 12-13g to 0.05-0.2g to 15-20g, and the reaction and continuous reaction conditions are that the reaction is carried out for 3-6h at a temperature of 100-110 ℃.
  7. 7. The preparation method of the slow-release composite material according to claim 1, wherein in the step (2), the molar ratio of polycaprolactone diol to isophorone diisocyanate to castor oil to tartaric acid is 1-2:3.5-4.2:0.5-1:0.5-1, the adding amount of dibutyltin dilaurate is 0.1-0.3% of the mass of the polycaprolactone diol, the reaction condition is that the reaction is carried out for 1h at 80 ℃ in nitrogen atmosphere, and the continuous reaction and the re-reaction condition are that the reaction is carried out for 1-2h at 55-65 ℃.
  8. 8. The method for preparing the sustained-release composite material according to claim 1, wherein in the step (2), the mass ratio of the bio-based polyurethane prepolymer to the epoxy resin modified bentonite to the amino silicone oil to the polyether amine is 85-90:10-15:3.5-4.5:2.5-3.5.
  9. 9. A sustained-release composite prepared by the method for preparing a sustained-release composite according to any one of claims 1 to 8.
  10. 10. Use of the slow release composite material according to claim 9 in potassium sulphate potash fertilizer.

Description

Sustained-release composite material, preparation method and application thereof in potassium sulfate potash fertilizer Technical Field The invention relates to the technical field of fertilizers, in particular to a slow-release composite material, a preparation method and application thereof in potassium sulfate potash fertilizers. Background Potassium is one of three main nutrients for crop growth, mainly derived from potash fertilizer, and has important effect on improving crop yield and quality. The existing potash fertilizer used in agricultural production mainly comprises potassium sulfate, potassium chloride and the like, the renewable property of potash fertilizer resources is low, and the potash fertilizer is fast to dissolve in soil and easy to run off, so that the utilization efficiency of the potash fertilizer is always one of the important problems in agricultural sustainable development, and the efficient utilization of the potash fertilizer can save resources and reduce the risk of causing environmental pollution. Therefore, the novel slow-release potash fertilizer and the application technology for efficiently utilizing the potash fertilizer are developed, the utilization rate of the potash fertilizer and the fertility of farmlands can be improved, and the sustainable development of agriculture is realized. The slow release fertilizer can be matched with the absorption requirement of crops by controlling the release rate of nutrients, so that the fertilizer utilization rate can be remarkably improved, the fertilization times can be reduced, and the environmental pollution can be reduced. At present, the coating material of the slow release fertilizer mainly depends on petroleum-based polymers, and has the problems of high cost, difficult degradation, poor environmental compatibility and the like although the film forming property and the slow release property are good. Although the pure biological base coating material is environment-friendly, the defects of poor mechanical property, unstable slow release, insufficient water resistance and the like are common, and the requirements of practical agricultural application are difficult to meet. Therefore, developing a sustained-release coating material with balanced performance and environmental friendliness becomes an important research direction in the current sustained-release fertilizer field. Disclosure of Invention The invention aims to overcome the defects of the prior art and provides a slow-release composite material, a preparation method and application thereof in potassium sulfate potash fertilizer. Epoxy resin modified bentonite is prepared by using epoxy vanillin, aldehyde modified bentonite and 1, 3-bis (3-aminopropyl) tetramethyl disiloxane, and is compounded with a bio-based polyurethane prepolymer, and then amino silicone oil and polyether amine are adopted for curing, and an inorganic material bentonite is introduced and a dynamic Schiff base bond is constructed, so that the slow-release composite material for the fertilizer, which is stable in structure and environment-friendly, is finally prepared, can be used as a coating material to be applied to potassium sulfate fertilizer, and realizes slow release of the potassium fertilizer. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: The preparation method of the slow-release composite material comprises the following steps: Step (1), mixing vanillin, tetrabutylammonium bromide and epichlorohydrin, reacting, cooling after the reaction is finished, dropwise adding a sodium hydroxide aqueous solution, stirring for continuous reaction after the dropwise adding is finished, and purifying after the reaction is finished to obtain the epoxidized vanillin; Step (2), mixing alkaline calcium bentonite and cyclohexane, performing ultrasonic dispersion, dropwise adding p-aldehyde benzoic acid mixed solution, reacting after the dropwise adding is finished, performing suction filtration, washing and drying after the reaction is finished to obtain aldehyde modified bentonite; Mixing aldehyde modified bentonite and dioxane, performing ultrasonic dispersion, adding 1, 3-bis (3-aminopropyl) tetramethyl disiloxane and acetic acid, reacting, adding epoxidized vanillin after the reaction is finished, continuing the reaction, cooling after the reaction is finished, and performing rotary evaporation to obtain epoxy resin modified bentonite; Mixing polycaprolactone dihydric alcohol and isophorone diisocyanate, adding dibutyl tin dilaurate, adding acetone to adjust viscosity, reacting, cooling after the reaction is finished, adding castor oil, continuing the reaction, adding tartaric acid after the reaction is finished, reacting again, and obtaining the bio-based polyurethane prepolymer after the reaction is finished; Mixing the bio-based polyurethane prepolymer, the epoxy resin modified bentonite, the amino silicone oil and the polyether amine to obtain