Polymer adjuvant for pesticide aerial application and synthesis method thereof

Abstract

The application discloses a kind of high-molecular adjuvant for pesticide aerial application and a synthesis method thereof.The synthesis method is to react polystyrene maleic anhydride alternating copolymer with acrylic acid to generate amphiphilic block copolymer, form a comb-shaped carbon chain structure by grafting polyethylene glycol monomethyl ether, and crosslink the high-molecular chain by hydrogen bond to construct a network structure, and then prepare the high-molecular adjuvant.The application provides strong electrostatic interaction by supramolecular recognition-hydrogen bond and space steric hindrance barrier by crosslinking structure, thereby enhancing the interaction force between the high-molecular adjuvant and the surface of target leaf.The high-molecular adjuvant prepared by the application can reduce droplet bounce, increase diffusion wetting area and effectively retain on crop leaves, and simultaneously improve the deposition performance of pesticide on the surface of target plant leaves.The application can greatly improve the utilization efficiency of pesticide in aerial application, reduce environmental pollution and economic loss.

Description

Technical Field

[0001] This invention belongs to the field of pesticide adjuvants, and relates to a class of polymeric adjuvants for aerial pesticide application, as well as a method for synthesizing the adjuvant. Background Technology

[0002] With the rapid development of modern agriculture in China, agricultural production technology has undergone comprehensive innovation, and various advanced equipment has been gradually applied to agricultural production, with drone technology being particularly well utilized. Using agricultural drones for plant disease and pest control can improve the coverage and effectiveness of spraying, as well as increase spraying precision. Drone spraying is more effective than manual spraying, providing more even coverage and better penetration of pesticides into plants, reaching even the roots. More importantly, compared to traditional spraying methods, it achieves separation of human and machine, posing almost no harm to the operator during spraying and improving safety. However, drone operation also has some drawbacks. The pesticide is susceptible to drift and evaporation after atomization, resulting in less atomized liquid reaching the target plant, increased evaporation loss of pesticide droplets, reduced control effectiveness, phytotoxicity, and pesticide contamination.

[0003] In the field of aerial spraying pesticide adjuvants, there is a need to develop more efficient and safer adjuvants that can improve pesticide utilization, promote pesticide penetration and absorption, and ensure the effectiveness of drone-based aerial spraying. Research has found that adding adjuvants with characteristics such as anti-evaporation, anti-drift, promoting sedimentation, and enhancing efficacy can overcome various adverse effects of the external environment on drone operations, improve pesticide utilization, enhance efficacy, and make field operations more reliable.

[0004] CN114634639A discloses a polycarboxylate dispersant, its synthesis method, and its application in pesticide adjuvants. The method involves reacting alternating polymers of styrene and maleic anhydride with N-isopropylacrylamide to generate a block copolymer. A graft copolymer is then formed by grafting polyethylene glycol. A crosslinking agent is used to crosslink the polymer chains through hydrogen bonding to construct a network structure, thereby preparing the final polycarboxylate dispersant. This dispersant exhibits excellent dispersion performance, effectively stabilizing and dispersing pesticide active ingredients. However, the N-isopropylacrylamide in the block copolymer cannot form richer hydrogen bonds with fatty acids, alcohols, and aldehydes on the surface of the leaf wax layer, and cannot generate stronger interactions with the leaf surface. Therefore, this polycarboxylate dispersant does not exhibit excellent deposition-promoting properties and cannot significantly promote the effective deposition and retention of pesticide spray droplets on the crop surface.

[0005] CN117694342A discloses a preparation method and application of a drone-specific adjuvant for plant protection. This adjuvant formulation consists of a plant-derived anti-drift agent, wetting agent, penetrant, defoamer, antifreeze agent, solubilizer, and water. It addresses current issues with drones spraying pesticides, such as small droplets, easy drift, and evaporation. CN116918805A discloses a drone adjuvant and its preparation method. The adjuvant includes dihydroxysuccinic acid, acetic acid, ethylene glycol, sorbitol, mannitol, ferrous sulfate, Tween-80, sodium benzoate, and water. It is used to improve the stability, spreading and penetrating properties, and anti-drift ability of pesticides.

[0006] The additives prepared by the aforementioned patents do not possess good amphiphilic properties, and their performance cannot be improved by adjusting the main structure of the additives themselves; the preparation process of the additives is relatively complicated and requires high technical expertise; moreover, the prepared additives are not inexpensive and have high costs. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a class of polymeric adjuvants for aerial pesticide application and their synthesis method. By modifying the molecular structure of previous polymers, a polystyrene-maleic anhydride alternating copolymer was synthesized and reacted with acrylic acid to generate a more hydrophilic amphiphilic block copolymer. A comb-shaped carbon chain structure was formed by grafting polyethylene glycol monomethyl ether, and then a crosslinking agent was used to crosslink the polymer chains through multiple hydrogen bonds to form a network structure. This resulted in a class of polymeric adjuvants with anti-evaporation, anti-drift, easy dispersion, low surface tension, and deposition-promoting properties. It can form richer hydrogen bonds with fatty acids, alcohols, and aldehydes on the waxy layer of leaves, enhancing the interaction between the polymeric adjuvant and the target leaf surface. This further improves the amount of pesticide solution it can carry when effectively adhering to the target plant leaves, allowing the pesticide solution to effectively deposit and remain on the crop surface after spraying, exhibiting excellent deposition-promoting performance. This, in turn, ensures the efficacy of the pesticide active ingredient and improves its utilization efficiency.

[0008] The present invention discloses the following technical solution:

[0009] In a first aspect, the present invention provides a class of polymeric auxiliaries: four types in total, namely, an aqueous solution of PAA-b-PSMA, an aqueous solution of a crosslinked product of PAA-b-PSMA and a crosslinking agent, an aqueous solution of PAA-b-PSMA-g-MPEG, and an aqueous solution of a crosslinked product of PAA-b-PSMA-g-MPEG and a crosslinking agent. The main structure of the polymeric auxiliaries is shown below:

[0010]

[0011] PAA-b-PSMA(x=25~200,y=15~500)

[0012]

[0013] PAA-b-PSMA-g-MPEG (x=25~200, y=15~500, n=3~20)

[0014] A second aspect of the present invention provides a method for synthesizing PAA-b-PSMA, a cross-linked product of PAA-b-PSMA and a cross-linking agent, PAA-b-PSMA-g-MPEG, and a cross-linked product of PAA-b-PSMA-g-MPEG and a cross-linking agent. The method comprises: reversibly adding-fragmenting chain transfer polymerization of styrene and maleic anhydride to synthesize intermediate PSMA; further polymerizing PSMA with acrylic acid as a macromolecular chain transfer agent to generate PAA-b-PSMA; grafting MPEG to synthesize PAA-b-PSMA-g-MPEG; and then cross-linking with a cross-linking agent to obtain a cross-linked product. PAA-b-PSMA, the cross-linked product of PAA-b-PSMA and a cross-linking agent, PAA-b-PSMA-g-MPEG, and the cross-linked product of PAA-b-PSMA-g-MPEG and a cross-linking agent are respectively added to water to form a homogeneous solution, thus preparing the final polymeric additive.

[0015] Furthermore, the specific steps of the synthesis method of the present invention are as follows:

[0016] Step 1: Styrene and maleic anhydride undergo reversible addition-fragmentation chain transfer polymerization to synthesize intermediate PSMA;

[0017] Step 2: The intermediate PSMA is used as a macromolecular chain transfer agent to further polymerize with acrylic acid to generate PAA-b-PSMA;

[0018] Step 3: Grafting MPEG to synthesize PAA-b-PSMA-g-MPEG;

[0019] Step 4: PAA-b-PSMA and PAA-b-PSMA-g-MPEG are cross-linked with cross-linking agents to obtain cross-linked products.

[0020] Step 5: Add PAA-b-PSMA, the cross-linked product of PAA-b-PSMA and the cross-linking agent, PAA-b-PSMA-g-MPEG, and the cross-linked product of PAA-b-PSMA-g-MPEG and the cross-linking agent to water respectively, and stir until the polymer or polymer cross-linked product is completely dissolved to form a homogeneous solution, thus preparing the polymer additive.

[0021] The intermediate PSMA is prepared by weighing maleic anhydride and an initiator, then adding an organic solvent containing styrene monomer and chain transfer reagent, stirring and heating to react, and then reprecipitating to obtain the intermediate PSMA after the reaction is completed.

[0022] Furthermore, the chain transfer reagent is benzyl dithiobenzoate; the initiator is azobisisobutyronitrile; the organic solvent is tetrahydrofuran, acetonitrile, or 1,4-dioxane; the molar ratio of styrene monomer to maleic anhydride is 0.2:1 to 3:1; the amount of chain transfer reagent is 1% to 4% of styrene monomer; the amount of initiator is 0.1% to 0.5% of chain transfer reagent; the reaction temperature is 50 to 90°C, the reaction time is 10 to 72 hours, and the solvent used for reprecipitation is n-hexane or petroleum ether.

[0023] The preparation method of PAA-b-PSMA is as follows: weigh intermediate PSMA and initiator, then add organic solvent of acrylic monomer, stir and heat to react, and after the reaction is completed, reprecipitate to obtain PAA-b-PSMA.

[0024] Furthermore, the initiator is azobisisobutyronitrile; the organic solvent is tetrahydrofuran, acetonitrile, or 1,4-dioxane; the amount of intermediate PSMA is 0.02% to 9% of the acrylic acid monomer; the amount of initiator is 0.1% to 0.5% of the intermediate PSMA; the reaction temperature is 60 to 100°C, the reaction time is 10 to 48 hours, and the solvent used for reprecipitation is n-hexane or petroleum ether.

[0025] The preparation method of PAA-b-PSMA-g-MPEG is as follows: weigh PAA-b-PSMA and catalyst, then add the organic solvent of polyethylene glycol monomethyl ether, stir and heat to react, and after the reaction is completed, reprecipitate to obtain PAA-b-PSMA-g-MPEG.

[0026] Furthermore, the molar ratio of PAA-b-PSMA-g-MPEG to MPEG is 1:0.5 to 1:3; the catalyst is pyridine or 4-dimethylaminopyridine; the molecular weight of MPEG is 200 to 1500; the organic solvent is tetrahydrofuran, N,N-dimethylformamide, or 1,4-dioxane; the reaction temperature is 50 to 130°C, the reaction time is 10 to 48 hours, and the solvent used for reprecipitation is n-hexane or petroleum ether.

[0027] The preparation method of the crosslinked product obtained by crosslinking PAA-b-PSMA and PAA-b-PSMA-g-MPEG with a crosslinking agent is as follows: the crosslinking agent is a small organic molecule with multiple hydrogen bond donors, preferably one or a mixture of two or more of diethylenetriamine, triethylamine, glucose, and amino acids. PAA-b-PSMA and PAA-b-PSMA-g-MPEG are reacted with the crosslinking agent in a solvent at a polymer:crosslinking agent molar ratio of 1:0.5 to 1:2 and a polymer:solvent mass ratio of 1:1 to 1:1000. The stirring time is 0.5 to 24 hours, and the crosslinked product is obtained when the mixture is homogeneous and the polymer is completely dissolved.

[0028] A third aspect of the present invention provides a mixture system of an aqueous suspension agent and a polymeric adjuvant, comprising an aqueous suspension agent and a polymeric adjuvant, wherein the polymeric pesticide adjuvant is used in an amount of 0.1% to 10% by weight of the final mixture system.

[0029] Compared with the prior art, the technical solution of the present invention has the following technical effects:

[0030] Based on a supramolecular recognition strategy, this invention develops a novel polymeric adjuvant for aerial application of pesticides. It integrates the advantages of polycarboxylate and polyethylene glycol, and can form more abundant hydrogen bonds with the leaf surface, enhancing the interaction between the polymeric adjuvant and the target leaf surface. It has better surface activity and anti-bounce properties, which can effectively promote the deposition and retention of pesticide solution on the crop surface, thereby ensuring the efficacy of pesticides and improving pesticide utilization. Attached Figure Description

[0031] The illustrative preparation examples and descriptions of the present invention are used to explain the present invention and do not constitute an improper limitation of the present invention.

[0032] Figure 1 The 1H NMR spectrum of the main structure PAA-b-PSMA prepared in Example 1 of this invention.

[0033] Figure 2 The infrared spectrum of the main structure PAA-b-PSMA prepared in Example 1 of this invention.

[0034] Figure 3 The hydrogen nuclear magnetic resonance spectrum of the main structure PAA-b-PSMA-g-MPEG prepared in Example 1 of this invention.

[0035] Figure 4 The infrared spectrum of the main structure PAA-b-PSMA-g-MPEG prepared in Example 1 of this invention.

[0036] Figure 5 This is a schematic diagram illustrating the interaction between the host structure and the guest structure prepared in Example 1 of the present invention.

[0037] Figure 6 Transmission electron microscopy image of PAA-b-PSMA self-assembled in water, prepared in Example 1 of this invention.

[0038] Figure 7 Transmission electron microscopy image of the cross-linked structure of PAA-b-PSMA and diethylenetriamine prepared in water for Example 1 of this invention.

[0039] Figure 8 Transmission electron microscopy image of PAA-b-PSMA-g-MPEG self-assembly in water, prepared for Example 1 of this invention.

[0040] Figure 9 Transmission electron microscopy image of the cross-linked structure of PAA-b-PSMA-g-MPEG and diethylenetriamine prepared in water for Example 1 of this invention.

[0041] Figure 10 A comparison chart showing the deposition rate performance with the addition of four polymeric additives.

[0042] Figure 11 A comparison chart showing the bounce performance of products with four different polymer additives. Detailed Implementation

[0043] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention is described.

[0044] Terminology Explanation:

[0045] Supramolecular interaction: A single entity with a specific structure and function formed by two or more subsystems through intermolecular forces. The intermolecular forces within a supramolecular system are non-covalent bonds, typically electrostatic interactions, hydrogen bonds, and van der Waals forces. This invention is constructed using intermolecular hydrogen bonding.

[0046] As described in the background section, aerial pesticide application suffers from drawbacks such as easy drift and evaporation after atomization, leading to increased evaporation loss of pesticide droplets and reduced control efficacy. Currently, there is an urgent need to research a polymeric pesticide adjuvant with characteristics such as anti-evaporation, anti-drift, promoting sedimentation, and enhancing efficacy.

[0047] In view of this, based on the supramolecular recognition strategy, this invention designs a class of network-structured polymeric auxiliaries, the structural formulas of their main structures PAA-b-PSMA and PAA-b-PSMA-g-MPEG are shown below:

[0048]

[0049] PAA-b-PSMA(x=25~200,y=15~500)

[0050]

[0051] PAA-b-PSMA-g-MPEG (x=25~200, y=15~500, n=3~20)

[0052] The design of the polymeric additive of this invention: A polystyrene-maleic anhydride alternating copolymer was synthesized using reversible addition-fragmentation chain transfer polymerization, which was then reacted with acrylic acid to generate an amphiphilic block copolymer. A comb-shaped carbon chain structure was formed by grafting polyethylene glycol monomethyl ether. A network structure was constructed by crosslinking the polymer chains through hydrogen bonding using a crosslinking agent. Then, PAA-b-PSMA, the crosslinked product of PAA-b-PSMA and the crosslinking agent, PAA-b-PSMA-g-MPEG, and the crosslinked product of PAA-b-PSMA-g-MPEG and the crosslinking agent were added to water and stirred until the polymer or the polymer crosslinked product was completely dissolved, forming a homogeneous solution, thus preparing the polymeric additive.

[0053] In a preferred preparation scheme of the present invention, a method for synthesizing the above-mentioned polymeric auxiliary agent host structures PAA-b-PSMA and PAA-b-PSMA-g-MPEG is also provided, the method comprising:

[0054] Styrene and maleic anhydride were subjected to reversible addition-fragmentation chain transfer polymerization to synthesize intermediate PSMA. The product was then used as a macromolecular chain transfer agent to further polymerize with acrylic acid to generate PAA-b-PSMA. MPEG was grafted onto the product to synthesize PAA-b-PSMA-g-MPEG, which was then crosslinked with a crosslinking agent to obtain a crosslinked product.

[0055] Its synthesis reaction formula is shown below:

[0056]

[0057] In the formula: (a) includes the initiator, chain transfer agent, organic solvent and reaction temperature; (b) includes the initiator, organic solvent and reaction temperature; (c) includes the catalyst and reaction temperature.

[0058] In the above synthesis method, maleic anhydride and initiator are commercially available and can be purified before use; styrene, acrylic acid, polyethylene glycol monomethyl ether and catalyst are commercially available and can be used directly; chain transfer reagents are existing substances that can be prepared by conventional methods by those skilled in the art, and no special limitations are required here. For example, benzyl dithiobenzoate (Advanced Materials (Weinheim, Germany), 24(41), 5617-5624; 2012) was prepared according to the method provided in the literature.

[0059] In a preferred embodiment of the present invention, the method for synthesizing the above-mentioned polymeric auxiliaries includes the following steps:

[0060] (1) Synthesis steps of intermediate PSMA

[0061] Weigh out maleic anhydride and initiator, then add styrene monomer and chain transfer reagent dissolved in organic solvent, stir and heat to react, and after the reaction is completed, reprecipitate to obtain intermediate PSMA.

[0062] As a preferred option, the chain transfer agent is benzyl dithiobenzoate.

[0063] Preferably, the initiator is azobisisobutyronitrile (AIBN).

[0064] Preferably, the organic solvent is tetrahydrofuran, acetonitrile, or 1,4-dioxane; more preferably, the solvent is 1,4-dioxane.

[0065] Preferably, the reaction temperature is 50–90°C, and even more preferably, the reaction temperature is 55–85°C.

[0066] Preferably, the reaction time is 10 to 72 hours, and even more preferably, the reaction time is 15 to 36 hours.

[0067] Preferably, the molar ratio of styrene monomer to maleic anhydride is 0.2:1 to 3:1; more preferably, it is 1.5:1.

[0068] Preferably, the amount of chain transfer reagent is 1% to 4% of the styrene monomer; more preferably, it is 1.5% to 3.5%.

[0069] Preferably, the amount of initiator is 0.1% to 0.5% of the chain transfer reagent; more preferably, it is 0.2% to 0.45%.

[0070] Preferably, the solvent used for reprecipitation is n-hexane or petroleum ether.

[0071] (2) Synthesis steps of PAA-b-PSMA

[0072] Weigh the intermediate PSMA and the initiator, then add the organic solvent of the acrylic monomer, stir and heat to react, and after the reaction is completed, reprecipitate to obtain PAA-b-PSMA.

[0073] Preferably, the initiator is azobisisobutyronitrile (AIBN).

[0074] Preferably, the organic solvent is tetrahydrofuran, acetonitrile, or 1,4-dioxane; more preferably, the solvent is 1,4-dioxane.

[0075] Preferably, the reaction temperature is 60–100°C, and more preferably, the reaction temperature is 65–95°C.

[0076] Preferably, the reaction time is 10 to 48 hours, and even more preferably, the reaction time is 15 to 36 hours.

[0077] Preferably, the amount of intermediate PSMA is 0.02% to 9% of the acrylic monomer.

[0078] Preferably, the amount of initiator is 0.1% to 0.5% of the intermediate PSMA.

[0079] Preferably, the solvent used for reprecipitation is n-hexane or petroleum ether.

[0080] (3) PAA-b-PSMA-g-MPEG synthesis steps

[0081] PAA-b-PSMA and catalyst were weighed, and then polyethylene glycol monomethyl ether was added as an organic solvent. The mixture was stirred and heated to react. After the reaction was completed, PAA-b-PSMA-g-MPEG was obtained by recrystallization.

[0082] Preferably, the molar ratio of PAA-b-PSMA to MPEG is 1:0.5 to 1:3.

[0083] Preferably, the catalyst is pyridine or 4-dimethylaminopyridine.

[0084] Preferably, the molecular weight of MPEG is 200-1500.

[0085] Preferably, the organic solvent is tetrahydrofuran, N,N-dimethylformamide, or 1,4-dioxane.

[0086] Preferably, the reaction temperature is 50–130°C.

[0087] Preferably, the reaction time is 10 to 48 hours.

[0088] Preferably, the solvent used for reprecipitation is n-hexane or petroleum ether.

[0089] (4) PAA-b-PSMA and PAA-b-PSMA-g-MPEG are crosslinked with a crosslinking agent to obtain crosslinked products.

[0090] A certain mass of PAA-b-PSMA, PAA-b-PSMA-g-MPEG and crosslinking agent were weighed out, and after being added to a solvent and stirred for a period of time, a crosslinked product was obtained.

[0091] Preferably, diethylenetriamine is used as the crosslinking agent. Using a small molecule crosslinking agent, especially an alkaline one, can simultaneously adjust the pH, resulting in better dispersant performance.

[0092] Preferably, the molar ratio of polymer to crosslinking agent is 1:0.5 to 1:2.

[0093] The ratio is ultimately determined by the assembly structure captured by transmission electron microscopy. If the ratio is lower than this, a stable structure cannot be formed; if the ratio is higher than this, the crosslinking agent is in excessive amount, resulting in reagent waste.

[0094] Preferably, the polymer:solvent mass ratio is 1:1 to 1:1000. The polymer and crosslinking agent are stirred in the solvent for 0.5 to 24 hours.

[0095] (5) Prepare polymeric additives from PAA-b-PSMA, PAA-b-PSMA-g-MPEG and their crosslinking products.

[0096] PAA-b-PSMA, the cross-linked product of PAA-b-PSMA and the cross-linking agent, PAA-b-PSMA-g-MPEG, and the cross-linked product of PAA-b-PSMA-g-MPEG and the cross-linking agent are added to water respectively and stirred until the polymer or the polymer cross-linked product is completely dissolved to form a homogeneous solution, which is the preparation of the polymer additive. The amount used is 0.1% to 10% based on the weight percentage of the polymer and its cross-linked product in the final system.

[0097] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific preparation examples.

[0098] Preparation Example 1

[0099] Step 1: Under an argon atmosphere, a 1,4-dioxane solution (10 mL) of styrene (1.56 g, 15 mmol) and benzyl dithiobenzoate (36.66 mg, 0.15 mmol) was added dropwise to maleic anhydride (980 mg, 10 mmol) and azobisisobutyronitrile (3.28 mg, 0.02 mmol). A freeze-pump-thaw degassing process was performed three times to remove residual oxygen. After thawing, the polymerization flask was placed directly into an oil bath preheated to 75°C. The polymerization reaction was carried out for 24 hours. After the reaction was completed, the system was cooled to room temperature, whereupon the reaction was quenched. The system was diluted with 1,4-dioxane to a suitable concentration and added dropwise to petroleum ether. A pink precipitate formed. The precipitate was redissolved in 1,4-dioxane and added dropwise to petroleum ether. This process was repeated twice to ensure complete monomer removal, yielding 1.97 g of pink solid PSMA, with a yield of 77.56%. Gel permeation chromatography (GPC) results: Mn = 8470, PDI = 1.23;

[0100] Step 2: Under an argon atmosphere, a 1,4-dioxane solution (15 mL) of acrylic acid (965.61 mg, 13.4 mmol) was added dropwise to the intermediate PSMA (1.626 g, 0.2 mmol) and azobisisobutyronitrile (16.42 mg, 0.1 mmol) obtained above. A freeze-pump-thaw degassing operation was performed three times to remove residual oxygen. After thawing, the polymerization flask was directly placed in an oil bath preheated to 90°C. The polymerization reaction was carried out for 24 hours. After the reaction was completed, the reaction was quenched upon cooling to room temperature. The treatment method was the same as that for PSMA, yielding 2.13 g of a light pink solid, with a yield of 82.25%. Gel permeation chromatography (GPC) results showed Mn = 12974 and PDI = 1.38. The proton NMR spectrum is shown below. Figure 1 As shown, the infrared spectrum is as follows Figure 2 As shown;

[0101] Step 3: Under an argon atmosphere, a 20 mL solution of 1,4-dioxane in polyethylene glycol monomethyl ether (Mn = 350, 1.79 g, 5.1 mmol) was added dropwise to PAA-b-PSMA (1.97 g) and the catalyst 4-dimethylaminopyridine (488.68 mg, 4 mmol). The reaction was carried out at 95 °C for 24 hours. After the reaction, the product was treated in the same way as the PSMA, yielding 2.82 g of a brown solid, with a yield of 75%. The 1H NMR spectrum is shown below. Figure 3 As shown, the infrared spectrum is as follows Figure 4 As shown.

[0102] Step 4: Take 1g of PAA-b-PSMA and 1g of PAA-b-PSMA-g-MPEG and stir them in a solvent with diethylenetriamine at a molar ratio of 1:2. After stirring for 5 hours, the cross-linked product is obtained.

[0103] Step 5: Add PAA-b-PSMA, the cross-linked product of PAA-b-PSMA and the cross-linking agent, PAA-b-PSMA-g-MPEG, and the cross-linked product of PAA-b-PSMA-g-MPEG and the cross-linking agent to water respectively, and stir until the polymer or polymer cross-linked product is completely dissolved to form a homogeneous solution, thus preparing the polymer additive.

[0104] A schematic diagram of the interaction between the host structure and the guest structure prepared in Example 1 is shown below. Figure 5 As shown.

[0105] Transmission electron microscopy (TEM) images of the PAA-b-PSMA and PAA-b-PSMA-g-MPEG self-assembled in solvent and cross-linked with diethylenetriamine in solvent, respectively, prepared in Example 1, are shown below. Figures 6-9 As shown.

[0106] Application Example 1

[0107] The above preparation example 1 and the deposition amount of the suspending agent and the suspending agent with four kinds of polymeric additives are compared.

[0108] Laser particle size analyzer

[0109] First, a 35% azoxystrobin·fluticasone suspension was prepared as shown in Table 1. The solvent, adjuvant, and technical grade pesticide were added in sequence to a beaker, stirred, and then modified zirconium oxide was added. The mixture was then placed in a sand mill for high-speed grinding under condensation for 3 hours. Particle size analysis using a laser particle size analyzer is shown in Table 2. D97 = 4.049 μm, reaching the optimal particle size and meeting the particle size standard for pesticide water suspensions. The mixture was then bottled and subjected to thermal stability tests at 54℃, cold stability tests at -18℃, and room temperature stability tests at 0℃. The remaining mixture was stored for 14 days and observed; its properties were stable, and it was ready for subsequent experiments.

[0110] Table 1

[0111] Serial Number name mass percentage 1 water 39.56％ 2 Ethylene glycol 5％ 3 dispersant 9％ 4 Magnesium aluminum silicate 0.5％ 5 Pyraclostrobin 20％ 6 Fluticasone 15％ 7 Xanthan Gum 10％ 8 Defoamer 0.3％

[0112] Table 2

[0113]

[0114] According to the People's Republic of China Agricultural Industry Standard - "Evaluation Method for Deposition Performance of Pesticide Tank Mixtures," the deposition amount was determined. The above-prepared suspension without any adjuvants was used as the control group, and suspensions with 3% of four different polymeric adjuvants were used as experimental groups. The results are as follows: Figure 10 As shown, 1-b represents the experimental group with the addition of the polymeric additive PAA-b-PSMA aqueous solution; 2-b / D represents the experimental group with the addition of the polymeric additive PAA-b-PSMA and the crosslinking agent in aqueous solution; 3-g represents the experimental group with the addition of the polymeric additive PAA-b-PSMA-g-MPEG aqueous solution; and 4-g / D represents the experimental group with the addition of the polymeric additive PAA-b-PSMA-g-MPEG and the crosslinking agent in aqueous solution.

[0115] The results showed that the deposition rate of the 35% azoxystrobin·fluticasone suspension containing the crosslinked aqueous solution of PAA-b-PSMA and crosslinking agent (2-b / D) and the 35% azoxystrobin·fluticasone suspension containing the PAA-b-PSMA-g-MPEG aqueous solution (3-g) increased by 0.32 mg / cm³ compared with the untreated group. 2 2.35 mg / cm 2 This indicates that the aqueous solution of the cross-linked product of the polymeric adjuvant PAA-b-PSMA and the cross-linking agent, as well as the aqueous solution of the polymeric adjuvant PAA-b-PSMA-g-MPEG, can improve the quality of the pesticide solution when it forms effective adhesion on the leaf surface of the target plant, so that the pesticide solution can be effectively deposited and retained on the crop surface after spraying.

[0116] Application Example 2

[0117] A droplet bouncing experiment was conducted using a high-speed camera. The high-speed camera was fixed to a stand and connected to a computer. A pipette was secured to a metal stand to ensure a stable droplet fall. A glass slide with a paraffin-sealed film was placed directly below the pipette. After connecting the instruments, the lighting source was turned on. The high-speed camera was turned on first, then the computer software was opened and connected to the instrument. The focus and camera height were adjusted to find a suitable position for the glass slide within the camera's field of view, ensuring the droplet's impact on the slide was clearly visible in the recording. The pipette was pressed to allow the droplet to fall freely. The recording was initiated the instant the droplet touched the glass slide, recording the process of the droplet contacting the slide and bouncing back.

[0118] Water without any polymeric additives was used as the control group, and aqueous solutions with four polymeric additives were used as the experimental groups for a bounce test. Five different concentrations of the four polymeric additives were set up: 0.5 mg / mL, 1 mg / mL, 2 mg / mL, 4 mg / mL, and 10 mg / mL. The aqueous solution sample with PAA-b-PSMA was group b; the cross-linked aqueous solution sample with PAA-b-PSMA and a cross-linking agent was group b / D; the aqueous solution sample with PAA-b-PSMA-g-MPEG was group g; the cross-linked aqueous solution sample with PAA-b-PSMA-g-MPEG and a cross-linking agent was group g / D; and the aqueous solution sample with commercially available PVP-K30 was group PVP. The results are as follows: Figure 11As shown, the time interval between each image is 10ms. The control group water sample bounces once on the slide, remaining a spherical droplet. The aqueous solutions with the four polymer additives spread out on the slide without bouncing, ultimately forming hemispherical or elliptical shapes. Higher concentrations result in greater spreading and less bouncing. The aqueous solution with PAA-b-PSMA and the cross-linked solution of PAA-b-PSMA and a cross-linking agent exhibited the best anti-bouncing performance; at the maximum concentration of 10mg / mL, both showed spreading without bouncing, and the spreading area was larger than that with the aqueous solution containing the commercially available polymer additive PVP-K30. The anti-bounce performance of the aqueous solutions containing the polymeric additive PAA-b-PSMA-g-MPEG and the cross-linked aqueous solutions of PAA-b-PSMA-g-MPEG with a cross-linking agent was worse than that of the aqueous solutions containing the polymeric additive PAA-b-PSMA and the cross-linked aqueous solutions of PAA-b-PSMA with a cross-linking agent. The anti-bounce performance of the aqueous solution containing the cross-linked aqueous solution of PAA-b-PSMA-g-MPEG with a cross-linking agent was similar to that of the aqueous solution containing the commercially available polymeric additive PVP-K30, with similar spreading area at the maximum concentration of 10 mg / mL.

[0119] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the inventive concept, and these all fall within the protection scope of the present invention.

Claims

1. The application of a polymeric adjuvant in aerial pesticide application, characterized in that, The polymeric additive is PAA- b -The aqueous solution of the crosslinked product of PSMA and the crosslinking agent, and the main structure of the polymeric auxiliaries are shown below: ； HEAD- b -PSMA(x=25~200,y=15~500) The polymeric additive needs to be mixed with an aqueous suspension agent for use, wherein the amount of the polymeric additive is 0.1% to 10% by weight of the final mixed system.

2. The application according to claim 1, characterized in that, The synthesis method of polymeric auxiliaries includes the following steps: Step 1: Styrene and maleic anhydride are polymerized via a reversible addition-fragmentation chain transfer polymerization method to obtain the intermediate PSMA; Step 2: Using intermediate PSMA as a macromolecular chain transfer agent, further polymerize it with acrylic acid to generate PAA- b -PSMA; Step 3, PAA- b -PSMA is cross-linked with a cross-linking agent to obtain a cross-linked product; Step 4: Apply PAA- b - The cross-linked product of PSMA and cross-linking agent is added to water and stirred until the polymer cross-linked product is completely dissolved to form a homogeneous solution, which is the preparation of the polymer additive.

3. The application according to claim 2, characterized in that, The intermediate PSMA is prepared by weighing maleic anhydride and an initiator, then adding an organic solvent containing styrene monomer and chain transfer reagent, stirring and heating to react, and then reprecipitating to obtain the intermediate PSMA after the reaction is completed.

4. The application according to claim 2, characterized in that, The PAA- b The preparation method of PSMA is as follows: weigh the intermediate PSMA and the initiator, then add the organic solvent of the acrylic monomer, and stir and heat at 60~100℃ for 10~48 hours. After the reaction is completed, reprecipitate to obtain PAA- b -PSMA, the amount of intermediate PSMA is 0.02%~9% of acrylic monomer.

5. The application according to claim 2, characterized in that, The PAA- b PSMA and crosslinking agent are stirred in a solvent at a polymer:crosslinking agent molar ratio of 1:0.5 to 1:2 and a polymer:solvent mass ratio of 1:1 to 1:1000. The stirring time is 0.5 to 24 hours. The crosslinked product is obtained when the mixture is stirred evenly and the polymer is completely dissolved.

6. The application according to claim 2 or 5, characterized in that, The crosslinking agent is one or a mixture of two or more of diethylenetriamine, triethylamine, glucose, and amino acids.

7. The application according to claim 5, characterized in that, The solvent is one or a mixture of two or more of water, N,N-dimethylformamide, dimethyl sulfoxide, and methanol.

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