Polycarboxylate surfactant containing tocopherol and application of polycarboxylate surfactant in pesticide

Abstract

The invention relates to the technical field of polycarboxylate surfactants containing tocopherol, and discloses a polycarboxylate surfactant containing tocopherol and application of the polycarboxylate surfactant in pesticides. Trans-1, 4-dichloro-2-butene, diethanol amine, phosphorus pentoxide and the like are used as raw materials, and an alkene-containing tetraphosphate intermediate is obtained through a substitution reaction and an esterification reaction. DL-alpha-tocopherol, maleic anhydride, polyethylene glycol and the like are used as raw materials, tocopherol modified polyethylene glycol is obtained through two-step reaction, an alkenyl structure contained in the tocopherol modified polyethylene glycol and raw materials such as acrylic acid and an alkene-containing tetraphosphate intermediate are copolymerized, and the polycarboxylate surfactant containing the tocopherol is obtained. When the prepared polycarboxylate surfactant containing tocopherol is applied to pesticides, the suspension effect and the heat storage stability of a pesticide water suspension agent can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of tocopherol-containing polycarboxylate surfactants, in particular to a tocopherol-containing polycarboxylate surfactant and application thereof in pesticides. Background Art

[0002] Pesticide suspension concentrate is a water-based pesticide formulation. During its storage, due to the Ostwald ripening phenomenon, flocculation and aggregation are prone to occur between particles. This is a thermodynamically unstable system. Therefore, it is necessary to add substances that can reduce the interfacial tension between the pesticide particles and the liquid medium to prevent the occurrence of Ostwald ripening. Surfactants are born.

[0003] Surfactants are substances that can disperse particles in a system, stabilize particles, and inhibit flocculation. Surfactants have three main modes of action in a system: (1) forming a double layer around particles, enhancing the electrostatic repulsion between particles. (2) reducing the interfacial energy of particles, inhibiting agglomeration between particles. (3) adsorbing on the surface of particles, increasing steric hindrance. Polycarboxylate surfactants are homopolymers or copolymers of monomers containing carboxylic acid groups. They are highly effective anionic surfactants, but studies have found that the effectiveness of single surfactants is not as good as that of mixed surfactant systems. Summary of the Invention

[0004] (1) Technical problems solved

[0005] In response to the deficiencies of the prior art, the present invention provides a tocopherol-containing polycarboxylate surfactant and its application in pesticides. Applying it to pesticide formulations can improve the suspension effect and heat storage stability of pesticide suspension concentrates.

[0006] (2) Technical solution

[0007] A method for preparing a tocopherol-containing polycarboxylate surfactant, comprising:

[0008] Under a nitrogen atmosphere, tocopherol-modified polyethylene glycol, acrylic acid, methyl methacrylate, tetraphosphate-containing olefin intermediate, and ammonium persulfate are added to deionized water, the temperature is controlled at 80-85° C., and the reaction is carried out for 2-5 hours. After the reaction is completed, a tocopherol-containing polycarboxylate surfactant is obtained.

[0009] In one embodiment, preferably, the mass ratio of the tocopherol-modified polyethylene glycol, acrylic acid, methyl methacrylate, tetraphosphate olefin-containing intermediate, and ammonium persulfate is 0.5-1:1:0.2-0.5:0.5-1:0.1-0.3.

[0010] In one embodiment, preferably, the preparation method of the tetraphosphoric acid alkene-containing intermediate is:

[0011] A1. Add trans-1,4-dichloro-2-butene to deionized water, add sodium hydroxide thereto, stir and mix evenly, then add diethanolamine thereto, react at 40-50° C. for 10-14 hours. After the reaction is complete, filter and evaporate to obtain intermediate 1;

[0012] A2. Add intermediate 1 to deionized water, stir and disperse, then add phosphorus pentoxide, react at 75-85°C for 2-5 hours. After the reaction is completed, filter, rotary evaporate, and dry to obtain the tetraphosphate olefin-containing intermediate.

[0013] In one embodiment, it is further preferred that in A1, the molar ratio of trans-1,4-dichloro-2-butene, sodium hydroxide, and diethanolamine is 1:1.2-1.4:2-2.4.

[0014] In one embodiment, it is further preferred that in A2, the molar ratio of the intermediate 1 to phosphorus pentoxide is 1:4.5-5.

[0015] In one embodiment, preferably, the preparation method of the tocopherol-modified polyethylene glycol is:

[0016] S1, adding DL-α-tocopherol, maleic anhydride, and triethylamine to cyclohexane solvent, reflux reaction for 10-14 hours, after the reaction is completed, adding deionized water, extracting with dichloromethane, washing with hydrochloric acid and deionized water in sequence, drying, and rotary evaporation to obtain carboxylated tocopherol;

[0017] S2. Add carboxylated tocopherol, polyethylene glycol, and p-toluenesulfonic acid to cyclohexane solvent, and reflux for 6-10 hours. After the reaction is completed, add saturated sodium bicarbonate solution, extract with ethyl acetate, wash with saturated sodium bicarbonate solution, dry, and rotary evaporate to obtain tocopherol-modified polyethylene glycol.

[0018] In one embodiment, further preferably, the molar ratio of DL-α-tocopherol, maleic anhydride, and triethylamine is 1:1.5-2:1.6-2.2.

[0019] In one embodiment, further preferably, the molar ratio of the carboxylated tocopherol, polyethylene glycol, and p-toluenesulfonic acid is 1:1:1.2-1.5.

[0020] In addition to the above technical solutions, the tocopherol-containing polycarboxylate surfactant prepared above can also be used in pesticides.

[0021] (3) Beneficial technical effects

[0022] The present invention utilizes trans-1,4-dichloro-2-butene and diethanolamine to undergo a substitution reaction under alkaline conditions to obtain an intermediate 1, and then utilizes the hydroxyl structure contained in the intermediate 1 to undergo esterification with phosphorus pentoxide to obtain a tetraphosphate olefin-containing intermediate. DL-α-tocopherol and maleic anhydride are reacted under the catalysis of triethylamine to obtain carboxylated tocopherol, which is then esterified with polyethylene glycol under the catalysis of p-toluenesulfonic acid to obtain tocopherol-modified polyethylene glycol. Finally, the olefinic structure contained in the tocopherol-modified polyethylene glycol is copolymerized with acrylic acid, the tetraphosphate olefin-containing intermediate, and the like under the initiation of ammonium persulfate to obtain a tocopherol-containing polycarboxylate surfactant.

[0023] The polycarboxylate surfactant containing tocopherol prepared by the present invention, the main chain structure and tocopherol structure thereof as the lipophilic end of the surfactant, it has more sites to anchor the pesticide particles, forms multi-point adsorption on the surface of the pesticide particles, plays a good anchoring effect, makes the surfactant difficult to transfer and desorb; the polyethylene glycol structure therein not only provides a large steric barrier to prevent the aggregation of pesticide particles, but also can be used with the hydrophilic end of the carboxyl structure and the phosphate structure as the surfactant, extending into the water phase, forming a large amount of negative charges around the surface of the original drug particles, providing a large electrostatic repulsion, destroying the aggregation of the granular pesticide particles, keeping the system stable, and improving the suspension effect of the pesticide suspension concentrate. In addition, the tetraphosphate-containing alkene intermediate prepared by the present invention wherein contains tetraphosphate structure, and the electrostatic repulsion effect between its molecules is larger than the electrostatic repulsion of the monophosphate structure, and the steric hindrance and electrostatic repulsion generated by it and the carboxylic acid structure and the polyethylene glycol structure are larger, and the suspension effect of the pesticide suspension concentrate is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a reaction process route of tetraphosphate containing olefin intermediate;

[0025] Figure 2 This is the reaction process route for tocopherol-modified polyethylene glycol. DETAILED DESCRIPTION

[0026] To facilitate understanding of the present invention, the present invention will be described more fully below, along with preferred embodiments thereof. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the disclosure of the present invention.

[0027] Example 1

[0028] (1) Add 0.5 mol of trans-1,4-dichloro-2-butene to 50 mL of deionized water, add 0.65 mol of sodium hydroxide, stir and mix evenly, then add 1 mol of diethanolamine, react at 45 °C for 12 h. After the reaction is completed, filter and evaporate to obtain intermediate 1.

[0029] (2) 0.2 mol of intermediate 1 was added to 50 mL of deionized water and stirred to disperse. Then 0.9 mol of phosphorus pentoxide was added thereto and reacted at 85 °C for 4 h. After the reaction was completed, the mixture was filtered, rotary evaporated, and dried to obtain the tetraphosphate olefin-containing intermediate.

[0030] (3) 0.1 mol of DL-α-tocopherol, 0.18 mol of maleic anhydride, and 0.22 mol of triethylamine were added to 200 mL of cyclohexane solvent and refluxed for 12 h. After the reaction, deionized water was added, and the mixture was extracted with dichloromethane. The mixture was washed with hydrochloric acid and deionized water in sequence, dried, and rotary evaporated to obtain carboxylated tocopherol.

[0031] (4) 0.1 mol of carboxylated tocopherol, 0.1 mol of polyethylene glycol 200, and 0.15 mol of p-toluenesulfonic acid were added to 200 mL of cyclohexane solvent and refluxed for 6 h. After the reaction, saturated sodium bicarbonate solution was added thereto, extracted with ethyl acetate, washed with saturated sodium bicarbonate solution, dried, and rotary evaporated to obtain tocopherol-modified polyethylene glycol.

[0032] (5) Under nitrogen atmosphere, 10 g of tocopherol-modified polyethylene glycol, 20 g of acrylic acid, 4 g of methyl methacrylate, 10 g of tetraphosphate-containing olefin intermediate, and 5 g of ammonium persulfate were added to 200 mL of deionized water. The temperature was controlled at 85 °C and the reaction was carried out for 4 h. After the reaction was completed, a tocopherol-containing polycarboxylate surfactant was obtained.

[0033] Example 2

[0034] (1) Add 0.5 mol of trans-1,4-dichloro-2-butene to 50 mL of deionized water, add 0.7 mol of sodium hydroxide, stir and mix evenly, then add 1.2 mol of diethanolamine, react at 50 °C for 10 h, filter and evaporate to obtain intermediate 1.

[0035] (2) Add 0.2 mol of intermediate 1 to 50 mL of deionized water, stir and disperse, then add 0.9 mol of phosphorus pentoxide, react at 75 °C for 4 h. After the reaction is completed, filter, rotary evaporate, and dry to obtain the tetraphosphate olefin intermediate.

[0036] (3) 0.1 mol of DL-α-tocopherol, 0.16 mol of maleic anhydride, and 0.18 mol of triethylamine were added to 200 mL of cyclohexane solvent and refluxed for 12 h. After the reaction, deionized water was added, and the mixture was extracted with dichloromethane. The mixture was washed with hydrochloric acid and deionized water in sequence, dried, and rotary evaporated to obtain carboxylated tocopherol.

[0037] (4) 0.1 mol of carboxylated tocopherol, 0.1 mol of polyethylene glycol 200, and 0.14 mol of p-toluenesulfonic acid were added to 200 mL of cyclohexane solvent and refluxed for 10 h. After the reaction, saturated sodium bicarbonate solution was added thereto, and the mixture was extracted with ethyl acetate, washed with saturated sodium bicarbonate solution, dried, and rotary evaporated to obtain tocopherol-modified polyethylene glycol.

[0038] (5) Under nitrogen atmosphere, 14 g of tocopherol-modified polyethylene glycol, 20 g of acrylic acid, 10 g of methyl methacrylate, 14 g of tetraphosphate-containing olefin intermediate, and 6 g of ammonium persulfate were added to 200 mL of deionized water. The temperature was controlled at 80 °C and the reaction was carried out for 5 h. After the reaction was completed, a tocopherol-containing polycarboxylate surfactant was obtained.

[0039] Example 3

[0040] (1) Add 0.5 mol of trans-1,4-dichloro-2-butene to 50 mL of deionized water, add 0.6 mol of sodium hydroxide, stir and mix evenly, then add 1 mol of diethanolamine, react at 40 °C for 14 h. After the reaction is completed, filter and evaporate to obtain intermediate 1.

[0041] (2) 0.2 mol of intermediate 1 was added to 50 mL of deionized water and stirred to disperse. Then 0.9 mol of phosphorus pentoxide was added thereto and reacted at 85 °C for 4 h. After the reaction was completed, the mixture was filtered, rotary evaporated, and dried to obtain the tetraphosphate olefin-containing intermediate.

[0042] (3) 0.1 mol of DL-α-tocopherol, 0.2 mol of maleic anhydride, and 0.16 mol of triethylamine were added to 200 mL of cyclohexane solvent and refluxed for 10 h. After the reaction, deionized water was added, and the mixture was extracted with dichloromethane. The mixture was washed with hydrochloric acid and deionized water in sequence, dried, and rotary evaporated to obtain carboxylated tocopherol.

[0043] (4) 0.1 mol of carboxylated tocopherol, 0.1 mol of polyethylene glycol 200, and 0.12 mol of p-toluenesulfonic acid were added to 200 mL of cyclohexane solvent and refluxed for 8 h. After the reaction, saturated sodium bicarbonate solution was added thereto, and the mixture was extracted with ethyl acetate, washed with saturated sodium bicarbonate solution, dried, and rotary evaporated to obtain tocopherol-modified polyethylene glycol.

[0044] (5) Under nitrogen atmosphere, 16 g of tocopherol-modified polyethylene glycol, 20 g of acrylic acid, 8 g of methyl methacrylate, 16 g of tetraphosphate-containing olefin intermediate, and 2 g of ammonium persulfate were added to 200 mL of deionized water. The temperature was controlled at 80 °C and the reaction was carried out for 2 h. After the reaction was completed, a tocopherol-containing polycarboxylate surfactant was obtained.

[0045] Example 4

[0046] (1) Add 0.5 mol of trans-1,4-dichloro-2-butene to 50 mL of deionized water, add 0.62 mol of sodium hydroxide, stir and mix evenly, then add 1 mol of diethanolamine, react at 45 °C for 14 h. After the reaction is completed, filter and evaporate to obtain intermediate 1.

[0047] (2) Add 0.2 mol of intermediate 1 to 50 mL of deionized water, stir and disperse, then add 1 mol of phosphorus pentoxide, react at 75 °C for 5 h. After the reaction is completed, filter, rotary evaporate, and dry to obtain the tetraphosphate olefin intermediate.

[0048] (3) 0.1 mol of DL-α-tocopherol, 0.18 mol of maleic anhydride, and 0.2 mol of triethylamine were added to 200 mL of cyclohexane solvent and refluxed for 14 h. After the reaction, deionized water was added, and the mixture was extracted with dichloromethane. The mixture was washed with hydrochloric acid and deionized water in sequence, dried, and rotary evaporated to obtain carboxylated tocopherol.

[0049] (4) 0.1 mol of carboxylated tocopherol, 0.1 mol of polyethylene glycol 200, and 0.14 mol of p-toluenesulfonic acid were added to 200 mL of cyclohexane solvent and refluxed for 8 h. After the reaction, saturated sodium bicarbonate solution was added thereto, and the mixture was extracted with ethyl acetate, washed with saturated sodium bicarbonate solution, dried, and rotary evaporated to obtain tocopherol-modified polyethylene glycol.

[0050] (5) Under nitrogen atmosphere, 18 g of tocopherol-modified polyethylene glycol, 20 g of acrylic acid, 8 g of methyl methacrylate, 18 g of tetraphosphate-containing olefin intermediate, and 5 g of ammonium persulfate were added to 200 mL of deionized water. The temperature was controlled at 80 °C and the reaction was carried out for 4 h. After the reaction was completed, a tocopherol-containing polycarboxylate surfactant was obtained.

[0051] Example 5

[0052] (1) Add 0.5 mol of trans-1,4-dichloro-2-butene to 50 mL of deionized water, add 0.65 mol of sodium hydroxide, stir and mix evenly, then add 1.2 mol of diethanolamine, react at 45 °C for 12 h. After the reaction is completed, filter and evaporate to obtain intermediate 1.

[0053] (2) Add 0.2 mol of intermediate 1 to 50 mL of deionized water, stir and disperse, then add 0.9 mol of phosphorus pentoxide, react at 80 °C for 2 h. After the reaction is completed, filter, rotary evaporate, and dry to obtain the tetraphosphate olefin intermediate.

[0054] (3) 0.1 mol of DL-α-tocopherol, 0.15 mol of maleic anhydride, and 0.22 mol of triethylamine were added to 200 mL of cyclohexane solvent and refluxed for 12 h. After the reaction, deionized water was added, and the mixture was extracted with dichloromethane. The mixture was washed with hydrochloric acid and deionized water in sequence, dried, and rotary evaporated to obtain carboxylated tocopherol.

[0055] (4) 0.1 mol of carboxylated tocopherol, 0.1 mol of polyethylene glycol 200, and 0.14 mol of p-toluenesulfonic acid were added to 200 mL of cyclohexane solvent and refluxed for 9 h. After the reaction, saturated sodium bicarbonate solution was added thereto, and the mixture was extracted with ethyl acetate, washed with saturated sodium bicarbonate solution, dried, and rotary evaporated to obtain tocopherol-modified polyethylene glycol.

[0056] (5) Under nitrogen atmosphere, 20 g of tocopherol-modified polyethylene glycol, 20 g of acrylic acid, 8 g of methyl methacrylate, 20 g of tetraphosphate-containing olefin intermediate, and 5 g of ammonium persulfate were added to 200 mL of deionized water. The temperature was controlled at 80 °C and the reaction was carried out for 5 h. After the reaction was completed, a tocopherol-containing polycarboxylate surfactant was obtained.

[0057] Comparative Example 1

[0058] (1) 0.1 mol of DL-α-tocopherol, 0.18 mol of maleic anhydride, and 0.22 mol of triethylamine were added to 200 mL of cyclohexane solvent and refluxed for 12 h. After the reaction, deionized water was added, and the mixture was extracted with dichloromethane. The mixture was washed with hydrochloric acid and deionized water in sequence, dried, and rotary evaporated to obtain carboxylated tocopherol.

[0059] (2) 0.1 mol of carboxylated tocopherol, 0.1 mol of polyethylene glycol 200, and 0.15 mol of p-toluenesulfonic acid were added to 200 mL of cyclohexane solvent and refluxed for 6 h. After the reaction, saturated sodium bicarbonate solution was added thereto, and the mixture was extracted with ethyl acetate, washed with saturated sodium bicarbonate solution, dried, and rotary evaporated to obtain tocopherol-modified polyethylene glycol.

[0060] (3) Under nitrogen atmosphere, 10 g of tocopherol-modified polyethylene glycol, 20 g of acrylic acid, 4 g of methyl methacrylate, and 5 g of ammonium persulfate were added to 200 mL of deionized water. The temperature was controlled at 85 °C and the reaction was carried out for 4 h. After the reaction was completed, a polycarboxylate surfactant was obtained.

[0061] Comparative Example 2

[0062] (1) Add 0.5 mol of trans-1,4-dichloro-2-butene to 50 mL of deionized water, add 0.65 mol of sodium hydroxide, stir and mix evenly, then add 1 mol of diethanolamine, react at 45 °C for 12 h. After the reaction is completed, filter and evaporate to obtain intermediate 1.

[0063] (2) 0.2 mol of intermediate 1 was added to 50 mL of deionized water and stirred to disperse. Then 0.9 mol of phosphorus pentoxide was added thereto and reacted at 85 °C for 4 h. After the reaction was completed, the mixture was filtered, rotary evaporated, and dried to obtain the tetraphosphate olefin-containing intermediate.

[0064] (3) 0.1 mol of maleic anhydride, 0.1 mol of polyethylene glycol 200, and 0.15 mol of p-toluenesulfonic acid were added to 200 mL of cyclohexane solvent and refluxed for 6 h. After the reaction, saturated sodium bicarbonate solution was added thereto, extracted with ethyl acetate, washed with saturated sodium bicarbonate solution, dried, and rotary evaporated to obtain modified polyethylene glycol.

[0065] (4) Under nitrogen atmosphere, 10 g of modified polyethylene glycol, 20 g of acrylic acid, 4 g of methyl methacrylate, 10 g of tetraphosphate olefin intermediate, and 5 g of ammonium persulfate were added to 200 mL of deionized water. The temperature was controlled at 85 °C and the reaction was carried out for 4 h. After the reaction was completed, a polycarboxylate surfactant was obtained.

[0066] 83.88 g of 93% tebuconazole technical, 8 g of polycarboxylate surfactant, 6 g of ethylene glycol, 10 g of xanthan gum, 0.4 g of AFE-3168 silicone defoamer, and 91.72 g of deionized water were added to a frosted bottle and stirred to dissolve. 200 g of zirconium beads with a diameter of 1.2 mm were added thereto, and the mixture was ground for 4 h to obtain a tebuconazole aqueous suspension.

[0067] The suspension rate of the preparation was determined according to the method of GB / T14825-2006. The preparation was placed in an electric constant temperature oven at 55°C for two weeks and then the suspension rate was tested.

[0068] Table 1: Suspension rate before and after heat storage of each embodiment and comparative example

[0069]

[0070] As can be seen from the table, in Examples 1-5, as the amount of tocopherol-modified polyethylene glycol and tetraphosphate-containing olefinic intermediate increases, the suspension effect increases, and the suspension rate can reach up to 99.9%; as can be seen from Example 1 and Comparative Examples 1-2, the suspension effect of the lack of any one of tocopherol-modified polyethylene glycol and tetraphosphate-containing olefinic intermediate is worse than that of Example 1, and the decrease in suspension rate before and after hot storage is worse than that of Comparative Example 1, indicating that the combination of tocopherol-modified polyethylene glycol and tetraphosphate-containing olefinic intermediate can effectively improve the storage stability and suspension rate of the aqueous suspension concentrate.

[0071] At room temperature, 0.1 g of the preparation was added to 100 mL of deionized water, shaken, and equilibrated in a special dish for Zeta potential measurement for 5 minutes to measure the Zeta potential of the pesticide surface.

[0072] Table 2: Zeta potential of various examples and comparative examples

[0073]

[0074] The larger the absolute value of the Zeta potential, the more stable the system and the better the dispersion effect. As can be seen from the table, the tocopherol-containing polycarboxylate surfactant prepared by the present invention has a good dispersion effect when applied to pesticides.

Claims

1. A tocopherol-containing polycarboxylate surfactant, characterized in that The preparation method of the polycarboxylate surfactant is: Under a nitrogen atmosphere, tocopherol-modified polyethylene glycol, acrylic acid, methyl methacrylate, tetraphosphate-containing olefin intermediate, and ammonium persulfate are added to deionized water, the temperature is controlled at 80-85° C., and the reaction is carried out for 2-5 hours. After the reaction is completed, a tocopherol-containing polycarboxylate surfactant is obtained.

2. The tocopherol-containing polycarboxylate surfactant according to claim 1, wherein The mass ratio of the tocopherol-modified polyethylene glycol, acrylic acid, methyl methacrylate, tetraphosphate olefin-containing intermediate, and ammonium persulfate is 0.5-1:1:0.2-0.5:0.5-10.1-0.

3.

3. The tocopherol-containing polycarboxylate surfactant according to claim 1, wherein The preparation method of the tetraphosphoric acid alkene-containing intermediate is as follows: A1. Add trans-1,4-dichloro-2-butene to deionized water, add sodium hydroxide thereto, stir and mix evenly, then add diethanolamine thereto, react at 40-50° C. for 10-14 hours. After the reaction is complete, filter and evaporate to obtain intermediate 1; A2. Add intermediate 1 to deionized water, stir and disperse, then add phosphorus pentoxide, react at 75-85°C for 2-5 hours. After the reaction is completed, filter, rotary evaporate, and dry to obtain the tetraphosphate olefin-containing intermediate.

4. The tocopherol-containing polycarboxylate surfactant according to claim 3, wherein In the above-mentioned A1, the molar ratio of trans-1,4-dichloro-2-butene, sodium hydroxide and diethanolamine is 1:1.2-1.4:2-2.

4.

5. The tocopherol-containing polycarboxylate surfactant according to claim 3, wherein In the above-mentioned A2, the molar ratio of the intermediate 1 to phosphorus pentoxide is 1:4.5-5.

6. The tocopherol-containing polycarboxylate surfactant according to claim 1, wherein The preparation method of the tocopherol-modified polyethylene glycol is: S1, adding DL-α-tocopherol, maleic anhydride, and triethylamine to cyclohexane solvent, reflux reaction for 10-14 hours, after the reaction is completed, adding deionized water, extracting with dichloromethane, washing with hydrochloric acid and deionized water in sequence, drying, and rotary evaporation to obtain carboxylated tocopherol; S2. Add carboxylated tocopherol, polyethylene glycol, and p-toluenesulfonic acid to cyclohexane solvent, and reflux for 6-10 hours. After the reaction is completed, add saturated sodium bicarbonate solution, extract with ethyl acetate, wash with saturated sodium bicarbonate solution, dry, and rotary evaporate to obtain tocopherol-modified polyethylene glycol.

7. The tocopherol-containing polycarboxylate surfactant according to claim 6, wherein The molar ratio of the DL-α-tocopherol, maleic anhydride and triethylamine is 1:1.5-2:1.6-2.

2.

8. The tocopherol-containing polycarboxylate surfactant according to claim 6, wherein The molar ratio of the carboxylated tocopherol, polyethylene glycol and p-toluenesulfonic acid is 1:1:1.2-1.

5.

9. Use of a tocopherol-containing polycarboxylate surfactant prepared by the preparation method according to claims 1 to 8 in pesticides.

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