Polyether for pesticide suspending agent and preparation method thereof

Abstract

The invention belongs to the technical field of pesticide adjuvants, and particularly relates to polyether for a pesticide suspending agent and a preparation method of the polyether. The preparation method comprises the following steps: (1) dehydrating aromatic diamine serving as an initiator, dropwise adding epoxypropane for reaction, and aging after dropwise adding to generate an intermediate aromatic diamine polyoxypropylene ether; (2) dehydrating the intermediate aromatic diamine polyoxypropylene ether serving as an initiator and potassium hydroxide serving as a catalyst, dropwise adding epoxypropane to react, and aging after dropwise adding; and (3) dropwise adding ethylene oxide to react, aging after dropwise adding, and performing post-treatment to obtain the polyether for the pesticide suspending agent. The polyether disclosed by the invention can be adsorbed on the surfaces of various pesticide particles to form a thick and stable hydration layer, so that the steric hindrance stability is improved; meanwhile, the polyether has good temperature resistance, and keeps a stable structure and a lasting function in long-term storage, so that the physical stability, the adaptability and the shelf life of the pesticide suspending agent are fundamentally improved.

Description

Technical Field

[0001] This invention belongs to the field of pesticide adjuvant technology, specifically relating to a polyether for pesticide suspension and its preparation method. Background Technology

[0002] Pesticide suspensions, as environmentally friendly and highly efficient water-based formulations, have become an important direction in pesticide formulation development. They are formed by stably dispersing water-insoluble solid pesticide active ingredients in the form of tiny particles in water with the help of surfactants and other adjuvants. This formulation has advantages such as being solvent-free, environmentally friendly, safe to use, and highly effective. However, the physical stability of suspensions (such as resistance to sedimentation, flocculation, crystal growth, and Austronesian ripening) is a key technical bottleneck restricting their product quality and shelf life.

[0003] In suspension formulations, surfactants, especially dispersants and wetting agents, play a decisive role in maintaining the stable dispersion of particles. Polyether surfactants, such as alkylphenol polyoxyethylene ethers, fatty alcohol polyoxyethylene ethers, and block polyethers (such as ethylene oxide-propylene oxide copolymers), are widely used in pesticide suspensions due to their excellent wetting, dispersing, and steric hindrance effects. They adsorb onto the surface of pesticide particles, forming a hydrophilic polymer layer that provides electrostatic repulsion and steric hindrance, preventing particles from approaching each other and agglomerating. However, commonly used polyether dispersants in the prior art still have several limitations: (1) Insufficient structural universality: The molecular structure of traditional polyethers is relatively simple, with fixed hydrophilic-lipophilic balance (HLB) values ​​and molecular chain segment arrangements. For pesticide technical materials with different polarities, crystal morphologies, and particle sizes, their adsorption adaptability and steric hindrance effects vary significantly. A polyether often only exhibits excellent dispersion effects for specific types of technical materials, lacking broad-spectrum adaptability. This leads to the need for frequent screening and compounding of multiple surfactants in formulation development, which is cumbersome and increases costs.

[0004] (2) Long-term storage may lead to precipitation or failure: During long-term storage, the periodic temperature changes cause the hydrophilic / lipophilic balance of the polyether chain to change. At lower temperatures, the polyether may desorb from the particle surface and disperse in water; at higher temperatures, the polyether molecular chain will curl on the particle surface, causing the particles to lose effective steric protection, resulting in problems such as paste formation, bottoming or particle size increase of the suspension, which seriously affects the shelf life and effectiveness of the formulation.

[0005] Therefore, there is an urgent need in this field to develop a polyether with strong structural universality and good temperature resistance. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a polyether for pesticide suspension and its preparation method. The polyether prepared by this method can be strongly adsorbed on the surface of various pesticide particles to form a thick and stable hydration layer, thereby improving the steric stability. At the same time, the polyether has good temperature resistance and maintains structural stability and long-lasting function during long-term storage, thereby fundamentally improving the physical stability, adaptability and shelf life of pesticide suspension and simplifying the formulation process.

[0007] To achieve the above objectives, this application provides the following technical solution: The method for preparing the polyether for pesticide suspension according to the present invention includes the following steps: (1) Using aromatic diamine as the initiator, after dehydration, propylene oxide (PO) is added dropwise to react. After the addition is completed, the product is aged to generate the intermediate aromatic diamine polyoxypropylene ether. (2) Using the intermediate aromatic diamine polyoxypropylene ether as the initiator and potassium hydroxide as the catalyst, after dehydration, propylene oxide is added dropwise to react, and aging is carried out after the addition is completed. (3) Add ethylene oxide (EO) dropwise and react. After the addition is complete, age the product and perform post-treatment to obtain polyether for pesticide suspension. The polyether structure of the pesticide suspension concentrate is as follows: , Wherein, R is an aromatic group of benzene, naphthalene, or diphenylmethane, m1, m2, m3, m4 = 13~18, n1, n2, n3, n4 = 14~19. Compared with traditional Pluronic block polyethers, this polyether structure can more effectively prevent the unstable deposition caused by the increase in pesticide particle size due to Austral ripening.

[0008] In step (1), the aromatic diamine is one or more of p-phenylenediamine, 4,4′-diaminodiphenylmethane, and 1,4-diaminonaphthalene.

[0009] In step (1), the reaction temperature is 150~165℃ and the aging temperature is 150~165℃.

[0010] In step (1), the intermediate aromatic diamine polyoxypropylene ether has the following structural formula: , Wherein, R is an aromatic group of benzene, naphthalene, or diphenylmethane.

[0011] In steps (1) and (2), the water content is reduced to less than 0.05% (corresponding to the mass percentage of the initiator in the step).

[0012] In step (2), the amount of potassium hydroxide used is 0.2 to 0.5% of the total mass of the intermediate aromatic diamine polyoxypropylene ether, potassium hydroxide, propylene oxide and ethylene oxide in step (3).

[0013] In step (2), the reaction temperature is 105~125℃ and the aging temperature is 105~125℃.

[0014] In step (3), the reaction temperature is 140~160℃ and the aging temperature is 140~160℃.

[0015] In step (3), the post-treatment is degassing and neutralization, with the pH set to 6-8.

[0016] In step (3), the ethylene oxide segment accounts for 45-50% of the molecular weight of the ethylene oxide and propylene oxide segments.

[0017] The pesticide suspension polyether of the present invention is prepared by the above-described preparation method of pesticide suspension polyether.

[0018] Preferably, the preparation method of the polyether for pesticide suspension of the present invention includes the following specific steps: (1) Using aromatic diamine as the starting agent, nitrogen gas is replaced three times, vacuum dehydration is performed, and after the moisture content is qualified (<0.05%), propylene oxide is added dropwise under slight positive pressure. The reaction temperature is controlled at 150~165℃. After the dropwise addition is completed, aging begins and the aging temperature is controlled at 150~165℃ to generate the intermediate aromatic diamine polyoxypropylene ether.

[0019] (2) Using the intermediate aromatic diamine polyoxypropylene ether as the initiator and potassium hydroxide as the catalyst, nitrogen was used to replace the water three times and vacuum dehydration was performed. After the water content was qualified (<0.05%), propylene oxide was added dropwise under slight positive pressure. The reaction temperature was controlled at 105~125℃. After the dropwise addition was completed, aging was started and the aging temperature was controlled at 105~125℃.

[0020] (3) After aging, ethylene oxide is added dropwise, and the reaction temperature is controlled at 140~160℃. After the addition is completed, aging begins, and the aging temperature is controlled at 140~160℃. After aging, the temperature is lowered and degassed. After degasing is completed, acetic acid is added to neutralize and adjust the pH to 6~8 to obtain polyether for pesticide suspension.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The polyether of the present invention has a star-shaped structure containing multiple PO segments, which can be better adsorbed on the surface of pesticide particles and provide strong steric hindrance. In addition, the polyether contains benzene ring, polybenzene ring or naphthalene ring structure, which can more easily bind tightly with most pesticides containing aromatic structures through π-π stacking. It is not easy to desorb in the suspension system. Compared with pesticide suspensions prepared by conventional Pluronic block polyether, the suspension function of this special polyether is better and the prepared suspension system is more stable.

[0022] (2) The polyether of the present invention has good temperature resistance and maintains structural stability and long-lasting function during long-term storage, thereby fundamentally improving the physical stability, adaptability and shelf life of pesticide suspensions and simplifying the formulation process. Attached Figure Description

[0023] Figure 1 This is the 1H NMR spectrum of the polyether from Example 1. Detailed Implementation

[0024] The present invention will be further described below with reference to the embodiments, but these embodiments do not limit the implementation of the present invention. Unless otherwise specified, all raw materials used in the embodiments are commercially available.

[0025] Example 1 370g of p-phenylenediamine was added to a 2.5L ethoxylation glass reactor, purged with nitrogen three times, and heated to 150℃ before adding propylene oxide (PO) dropwise. The amount of PO was set at 630g, and the reaction temperature of PO was controlled at 155℃. After the dropwise addition was completed, aging began, and the aging temperature of PO was controlled at 155℃. After the aging of PO was completed, the temperature was lowered to 100℃, degassed for 20 minutes, and then further lowered to 80℃ to obtain the intermediate p-phenylenediamine polyoxypropylene ether, which was then set aside for later use.

[0026] 109.7 g of intermediate terephthalamide polyoxypropylene ether and 3.6 g of potassium hydroxide were added to a 2.5 L glass autoclave for ethoxylation. The mixture was purged with nitrogen three times and dehydrated under vacuum at 100 °C for 3 hours. Then, propylene oxide (PO) was added dropwise at a set amount of 899 g, and the PO reaction temperature was controlled at 120 °C. After the addition was complete, aging began, and the PO aging temperature was controlled at 120 °C. After the PO aging was complete, ethylene oxide (EO) was added dropwise at a set amount of 792 g, and the EO reaction temperature was controlled at 145 °C. After the EO aging was complete, the temperature was lowered to 100 °C and degassed for 20 min. The temperature was then further lowered to 80 °C, and the mixture was neutralized with acetic acid to adjust the pH to 7, thus obtaining terephthalamide polyoxypropylene polyoxyethylene block polyether.

[0027] The p-phenylenediamine polyoxypropylene polyoxyethylene block polyether in Example 1 has a designed molecular weight of 6042, of which the PO segment has a molecular weight of 3248, a degree of polymerization of PO of 56, and m1, m2, m3, m4 = 14; the EO segment has a molecular weight of 2657, a degree of polymerization of EO of 60.4, and n1, n2, n3, n4 = 15.1, and the EO segment accounts for 45% of the total molecular weight of EOPO.

[0028] like Figure 1 As shown in the 1H NMR spectrum, the chemical shifts at 6.82 ppm and 7.11 ppm are hydrogen peaks on the benzene ring, the chemical shift at 1.15 ppm is a hydrogen peak on the methyl group of propylene oxide, and the chemical shift at 3.63 ppm is a hydrogen peak on the methylene group of ethylene oxide and the methylene and methine groups of propylene oxide. The EOPO mass ratio m(EO) / m(PO) calculated by NMR is (2.43 / 1-1)×0.75×44 / 58=0.814, and the EO mass percentage is 0.814 / 1.814×100%=44.9%, which is basically consistent with the theoretical value of 45%.

[0029] Example 2 405g of 1,4-diaminonaphthalene was added to a 2.5L ethoxylation glass reactor, purged with nitrogen three times, and heated to 150℃ before adding propylene oxide (PO) dropwise. The amount of PO was set at 594g, and the reaction temperature of PO was controlled at 160℃. After the dropwise addition was completed, aging began, and the aging temperature of PO was controlled at 160℃. After the aging of PO was completed, the temperature was lowered to 105℃, degassed for 15 minutes, and then further lowered to 70℃ to obtain the intermediate 1,4-diaminonaphthalene polyoxypropylene ether, which was then set aside for later use.

[0030] 113.4 g of intermediate 1,4-diaminonaphthalene polyoxypropylene ether and 5.4 g of potassium hydroxide were added to a 2.5 L ethoxylation glass reactor. The mixture was purged with nitrogen three times and dehydrated under vacuum at 105 °C for 3 hours. Then, propylene oxide (PO) was added dropwise at a set amount of 876.5 g, and the PO reaction temperature was controlled at 115 °C. After the dropwise addition was completed, aging began, and the PO aging temperature was controlled at 115 °C. After the PO aging was completed, ethylene oxide (EO) was added dropwise at a set amount of 810 g, and the EO reaction temperature was controlled at 150 °C. After the EO aging was completed, the temperature was lowered to 110 °C and degassed for 20 min. The temperature was then further lowered to 80 °C, and the mixture was neutralized with acetic acid to adjust the pH to 8, thus obtaining 1,4-diaminonaphthalene polyoxypropylene polyoxyethylene block polyether.

[0031] The 1,4-diaminonaphthalene polyoxypropylene polyoxyethylene block polyether in Example 2 has a designed molecular weight of 6193, of which the PO segment has a molecular weight of 3248, a degree of polymerization of PO of 56, and m1, m2, m3, m4 = 14; the EO segment has a molecular weight of 2787, a degree of polymerization of EO of 63.2, and n1, n2, n3, n4 = 15.8, and the EO segment accounts for 46.2% of the total molecular weight of EOPO.

[0032] Example 3 405g of 1,4-diaminonaphthalene was added to a 2.5L ethoxylation glass reactor, purged with nitrogen three times, and heated to 150℃ before adding propylene oxide (PO) dropwise. The amount of PO was set at 594g, and the reaction temperature of PO was controlled at 160℃. After the dropwise addition was completed, aging began, and the aging temperature of PO was controlled at 160℃. After the aging of PO was completed, the temperature was lowered to 105℃, degassed for 15 minutes, and then further lowered to 70℃ to obtain the intermediate 1,4-diaminonaphthalene polyoxypropylene ether, which was then set aside for later use.

[0033] In a 2.5L ethoxylation glass reactor, 94.5g of intermediate 1,4-diaminonaphthalene polyoxypropylene ether and 9g of potassium hydroxide were added. The mixture was purged with nitrogen three times and dehydrated under vacuum at 105℃ for 3 hours. Then, propylene oxide (PO) was added dropwise at a set amount of 912.5g, with the PO reaction temperature controlled at 105℃. After the dropwise addition was completed, aging began, with the PO aging temperature controlled at 105℃. After the PO aging was completed, ethylene oxide (EO) was added dropwise at a set amount of 792g, with the EO reaction temperature controlled at 150℃. After the EO aging was completed, the temperature was lowered to 110℃ and degassed for 15 minutes. The temperature was then further lowered to 80℃, and the mixture was neutralized with acetic acid to adjust the pH to 8, yielding 1,4-diaminonaphthalene polyoxypropylene polyoxyethylene block polyether.

[0034] The 1,4-diaminonaphthalene polyoxypropylene polyoxyethylene block polyether in Example 3 has a designed molecular weight of 7430, of which the PO segment has a molecular weight of 4000, a degree of polymerization of 68.8, and m1, m2, m3, m4 = 17.2; the EO segment has a molecular weight of 3272, a degree of polymerization of 74.4, and n1, n2, n3, n4 = 18.6, and the EO segment accounts for 45% of the total molecular weight of EOPO.

[0035] Example 4 461g of 4,4′-diaminodiphenylmethane was added to a 2.5L ethoxylation glass reactor. After nitrogen purging three times, the temperature was raised to 150℃ and propylene oxide (PO) was added dropwise. The amount of PO was set at 539g, and the reaction temperature of PO was controlled at 165℃. After the dropwise addition was completed, aging began, and the aging temperature of PO was controlled at 165℃. After the aging of PO was completed, the temperature was lowered to 110℃ and degassed for 15 minutes. The temperature was then further lowered to 70℃ to obtain the intermediate 4,4′-diaminodiphenylmethane polyoxypropylene ether, which was then set aside for later use.

[0036] 108g of intermediate 4,4′-diaminodiphenylmethane polyoxypropylene ether and 9g of potassium hydroxide were added to a 2.5L ethoxylation glass reactor. The mixture was purged with nitrogen three times and dehydrated under vacuum at 110℃ for 3 hours. Then, propylene oxide (PO) was added dropwise at a set amount of 874g, and the PO reaction temperature was controlled at 105℃. After the dropwise addition was completed, aging began, and the PO aging temperature was controlled at 105℃. After the PO aging was completed, ethylene oxide (EO) was added dropwise at a set amount of 826g, and the EO reaction temperature was controlled at 140℃. After the EO aging was completed, the temperature was lowered to 105℃ and degassed for 20 minutes. The temperature was then further lowered to 80℃, and the mixture was neutralized with acetic acid to adjust the pH to 6.5 to obtain 4,4′-diaminodiphenylmethane polyoxypropylene polyoxyethylene block polyether.

[0037] The 4,4′-diaminodiphenylmethane polyoxypropylene polyoxyethylene block polyether in Example 4 has a designed molecular weight of 7202, of which the PO segment has a molecular weight of 3712, a degree of polymerization of 64, and m1, m2, m3, m4 = 16; the EO segment has a molecular weight of 3292, a degree of polymerization of 74.8, and n1, n2, n3, n4 = 18.7, and the EO segment accounts for 47% of the total molecular weight of EOPO.

[0038] Comparative Example 1 122g of 1,2-propanediol was added to a 2.5L ethoxylation glass reactor, purged with nitrogen three times, and the temperature was raised to 110℃. Propylene oxide (PO) was then added dropwise. The amount of PO was set at 1478g, and the reaction temperature of PO was controlled at 110℃. After the dropwise addition was completed, aging began, and the aging temperature of PO was controlled at 110℃. After the aging of PO was completed, the temperature was lowered to 100℃, degassed for 15 minutes, and then further lowered to 80℃ to obtain intermediate PPG1000, which was then set aside for later use.

[0039] 277g of intermediate PPG1000 and 5.4g of potassium hydroxide were added to a 2.5L ethoxylation glass reactor. The mixture was purged with nitrogen three times and dehydrated under vacuum at 110℃ for 3 hours. Then, propylene oxide (PO) was added dropwise at a set amount of 623g, with the PO reaction temperature controlled at 105℃. After the dropwise addition was completed, aging began, with the PO aging temperature controlled at 105℃. After the PO aging was completed, ethylene oxide (EO) was added dropwise at a set amount of 900g, with the EO reaction temperature controlled at 150℃. After the EO aging was completed, the temperature was lowered to 100℃ and degassed for 15 minutes. The temperature was then further lowered to 70℃, and the mixture was neutralized with acetic acid to adjust the pH to 7, yielding polyoxypropylene-polyoxyethylene block polyether (BASF Pluronic 10500).

[0040] In Comparative Example 1, BASF Pluronic 10500 was designed with a molecular weight of 6500, of which the PO segment had a molecular weight of 3250 and a degree of polymerization of PO of 56; the EO segment had a molecular weight of 3250 and a degree of polymerization of EO of 74.

[0041] Comparative Example 2 405g of 1,4-diaminonaphthalene was added to a 2.5L ethoxylation glass reactor, purged with nitrogen three times, and heated to 150℃ before adding propylene oxide (PO) dropwise. The amount of PO was set at 594g, and the reaction temperature of PO was controlled at 160℃. After the dropwise addition was completed, aging began, and the aging temperature of PO was controlled at 160℃. After the aging of PO was completed, the temperature was lowered to 105℃, degassed for 15 minutes, and then further lowered to 70℃ to obtain the intermediate 1,4-diaminonaphthalene polyoxypropylene ether, which was then set aside for later use.

[0042] 136.2 g of intermediate 1,4-diaminonaphthalene polyoxypropylene ether and 5.4 g of potassium hydroxide were added to a 2.5 L ethoxylation glass reactor. The mixture was purged with nitrogen three times and dehydrated under vacuum at 105 °C for 3 hours. Then, propylene oxide (PO) was added dropwise at a set amount of 1053.1 g, and the PO reaction temperature was controlled at 115 °C. After the dropwise addition was completed, aging began, and the PO aging temperature was controlled at 115 °C. After the PO aging was completed, ethylene oxide (EO) was added dropwise at a set amount of 610.7 g, and the EO reaction temperature was controlled at 150 °C. After the EO aging was completed, the temperature was lowered to 110 °C and degassed for 20 min. The temperature was then further lowered to 80 °C, and the mixture was neutralized with acetic acid to adjust the pH to 8, thus obtaining 1,4-diaminonaphthalene polyoxypropylene polyoxyethylene block polyether.

[0043] The 1,4-diaminonaphthalene polyoxypropylene polyoxyethylene block polyether in Comparative Example 2 was designed with a molecular weight of 5155, of which the PO segment had a molecular weight of 3248, a degree of polymerization of PO of 56, and m1, m2, m3, m4 = 14; the EO segment had a molecular weight of 1749, a degree of polymerization of EO of 40, and n1, n2, n3, n4 = 10, and the EO segment accounted for 35% of the total molecular weight of EOPO.

[0044] Comparative Example 3 461g of 4,4′-diaminodiphenylmethane was added to a 2.5L ethoxylation glass reactor. After nitrogen purging three times, the temperature was raised to 150℃ and propylene oxide (PO) was added dropwise. The amount of PO was set at 539g, and the reaction temperature of PO was controlled at 165℃. After the dropwise addition was completed, aging began, and the aging temperature of PO was controlled at 165℃. After the aging of PO was completed, the temperature was lowered to 110℃ and degassed for 15 minutes. The temperature was then further lowered to 70℃ to obtain the intermediate 4,4′-diaminodiphenylmethane polyoxypropylene ether, which was then set aside for later use.

[0045] In a 2.5L ethoxylation glass reactor, 91.7g of intermediate 4,4′-diaminodiphenylmethane polyoxypropylene ether and 9g of potassium hydroxide were added. The mixture was purged with nitrogen three times and dehydrated under vacuum at 110℃ for 3 hours. Then, propylene oxide (PO) was added dropwise at a set amount of 741.6g, with the PO reaction temperature controlled at 105℃. After the dropwise addition was complete, aging began, with the PO aging temperature controlled at 105℃. After the PO aging was complete, ethylene oxide (EO) was added dropwise at a set amount of 966.8g, with the EO reaction temperature controlled at 140℃. After the EO aging was complete, the temperature was lowered to 105℃, degassed for 20 minutes, and then further lowered to 80℃. Acetic acid was added to neutralize and adjust the pH to 6.5, yielding 4,4′-diaminodiphenylmethane polyoxypropylene polyoxyethylene block polyether.

[0046] The 4,4′-diaminodiphenylmethane polyoxypropylene polyoxyethylene block polyether in Comparative Example 3 has a designed molecular weight of 8447, of which the PO segment has a molecular weight of 3712, a degree of polymerization of PO of 64, and m1, m2, m3, m4 = 16; the EO segment has a molecular weight of 4537, a degree of polymerization of EO of 103.2, and n1, n2, n3, n4 = 25.8. The EO segment accounts for 55% of the total molecular weight of EOPO.

[0047] The polyethers synthesized in Examples 1-4 and Comparative Examples 1-3 were used to prepare pesticide suspensions according to the following formulations, and the suspension properties of the pesticide suspensions were then tested according to GB / T 14825-2023 standard. The formulations are shown in Table 1.

[0048] Table 1 Pesticide suspension formulation

[0049] The difenoconazole in the table above is from Weifang Lefeng Biological Pesticide Co., Ltd.; pyraclostrobin is from Hubei Huiheyuan Chemical Co., Ltd.; TERSPERSE 2020 is from Shanghai Kaiyin Chemical Co., Ltd.; xanthan gum is from Jinan Shengshi Biotechnology Co., Ltd.; magnesium aluminum silicate is from Jinan Jinyu Chemical Co., Ltd.; SAG630 is from Henan Zegang Environmental Protection Technology Co., Ltd.; and ethylene glycol is from Shanghai Dongda Chemical Co., Ltd.

[0050] The results of the suspension performance test are shown in Table 2.

[0051] Table 2. Results of Suspension Performance Experiment

[0052] As can be seen from the table, the suspension stability of the suspensions prepared with the suspending agents of Examples 1-4 is better than that of the suspensions prepared with polyethers in Comparative Examples 1, 2, and 3.

Claims

1. A method for preparing a polyether for pesticide suspension, characterized in that: Includes the following steps: (1) Using aromatic diamine as the initiator, after dehydration, propylene oxide is added dropwise to react. After the addition is completed, the product is aged to generate the intermediate aromatic diamine polyoxypropylene ether. (2) Using the intermediate aromatic diamine polyoxypropylene ether as the initiator and potassium hydroxide as the catalyst, after dehydration, propylene oxide is added dropwise to react, and aging is carried out after the addition is completed. (3) Add ethylene oxide dropwise, age after addition, and then perform post-treatment to obtain polyether for pesticide suspension. The polyether structure of the pesticide suspension concentrate is as follows: ， Wherein, R is an aromatic group of benzene, naphthalene or diphenylmethane, m1, m2, m3, m4 = 13~18, n1, n2, n3, n4 = 14~19.

2. The method for preparing polyether for pesticide suspension according to claim 1, characterized in that: In step (1), the aromatic diamine is one or more of p-phenylenediamine, 4,4′-diaminodiphenylmethane, and 1,4-diaminonaphthalene.

3. The method for preparing polyether for pesticide suspension according to claim 1, characterized in that: In step (1), the reaction temperature is 150~165℃ and the aging temperature is 150~165℃.

4. The method for preparing polyether for pesticide suspension according to claim 1, characterized in that: In step (1), the intermediate aromatic diamine polyoxypropylene ether has the following structural formula: ， Wherein, R is an aromatic group of benzene, naphthalene, or diphenylmethane.

5. The method for preparing polyether for pesticide suspension according to claim 1, characterized in that: In step (2), the amount of potassium hydroxide used is 0.2 to 0.5% of the total mass of the intermediate aromatic diamine polyoxypropylene ether, potassium hydroxide, propylene oxide and ethylene oxide in step (3).

6. The method for preparing polyether for pesticide suspension according to claim 1, characterized in that: In step (2), the reaction temperature is 105~125℃ and the aging temperature is 105~125℃.

7. The method for preparing polyether for pesticide suspension according to claim 1, characterized in that: In step (3), the reaction temperature is 140~160℃ and the aging temperature is 140~160℃.

8. The method for preparing polyether for pesticide suspension according to claim 1, characterized in that: In step (3), the post-treatment is degassing and neutralization, with the pH set to 6-8.

9. The method for preparing polyether for pesticide suspension according to claim 1, characterized in that: In step (3), the ethylene oxide segment accounts for 45-50% of the molecular weight of the ethylene oxide and propylene oxide segments.

10. A polyether for pesticide suspension, characterized in that: It is prepared by the method for preparing pesticide suspension polyether according to any one of claims 1-9.

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