Lignin-polyether, preparation method thereof and application of lignin-polyether as carrier in pesticide preparation

Abstract

The invention discloses lignin-polyether, a preparation method thereof and application of the lignin-polyether as a carrier in a pesticide preparation. The method comprises the following steps: reacting a hydroxyl-containing surfactant with isocyanato in a nitrogen atmosphere to obtain an isocyanato-terminated intermediate, carrying out nucleophilic substitution reaction on the intermediate and the hydroxyl in alkali lignin, and inoculating the intermediate into lignin to prepare lignin-polyether. Lignin-polyether serves as a carrier, abamectin and an ultraviolet absorbent are loaded to prepare the nano-microspheres, the average particle size is smaller than or equal to 260 nm, the photolysis retention rate is increased by 4.1 times or above compared with a commercial microemulsion, and the stability and the photolysis resistance of the pesticide prone to photolysis are remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of natural polymer materials, and particularly relates to a lignin-polyether, a preparation method thereof and application of the lignin-polyether as a carrier in a pesticide preparation. The lignin-polyether as a carrier for preparing a pesticide preparation can effectively reduce or even avoid photodegradation of a photolabile pesticide molecule. BACKGROUND

[0002] Pesticides play an important role in resisting biological disasters and promoting sustainable development of pesticides. However, after spraying, whether residual on the plant surface or entering the soil, water and atmosphere, the pesticides will be irradiated by sunlight and cause a certain degree of photochemical degradation. Pesticide photolysis is mainly divided into two types, direct degradation and indirect degradation. Direct degradation refers to that the pesticide directly absorbs radiation energy to cause bond rupture and degradation, and indirect degradation refers to that the dissociation energy of the pesticide molecule bond is high, and usually other substances are used as carriers to absorb light energy, and then energy transfer is carried out through the carriers to cause the pesticide molecule to jump to an excited state and cause indirect photolysis. The pesticides of direct photolysis usually contain conjugated double bonds, ether bonds and aromatic rings and other unsaturated bonds, such as abamectin, emamectin benzoate and spinosyn. Compared with the pesticides of indirect photolysis, the pesticides of direct photolysis are more likely to jump to an excited state under irradiation, causing bond rupture to generate small molecules. Pesticide photolysis failure affects the control effect, so that the pesticide spraying frequency has to be increased, resulting in increased cost of chemical control; the products after photolysis have reduced toxicity to target organisms and significantly enhanced harm to non-target organisms. In recent years, with the in-depth study of pesticide photochemical theory, people have begun to study how to reduce pesticide photolysis to prevent pollution and protect the environment.

[0003] Yan's team used environmental waste blue-green algae as raw material to encapsulate abamectin (AVM), and the obtained microspheres had a certain slow-release performance. The encapsulated AVM showed better light stability than free AVM. Zheng Yajing's team used gelatin and gum arabic as wall materials to prepare natalizumab (NA) microcapsules by complex coacervation method, and the microcapsules had spherical or elliptical appearance. After 110 min of ultraviolet irradiation, the residual amount of NA was 41.5%. Zhang Xiaqing et al. found that the photolysis of acetonitrile cyclopentene pyrethrin had a quenching effect. The photolysis half-life of cyclopentene pyrethrin in water was 50.59 min, and after adding 10% acetone, the photolysis half-life was prolonged to 83.51 min, mainly because the absorption wavelength of the pesticide itself and the absorption of short-wave ultraviolet light by the organic solvent were related.

[0004] The above-mentioned methods of loading photolabile pesticides by carriers or adding organic solvents still have the following problems: 1. The photolysis of the original pesticide after encapsulation is still serious; 2. The stability of the preparation is poor, which is not conducive to long-term storage; 3. The addition of organic solvents has a great burden on the environment.

[0005] Lignin is a natural polymer compound with the second highest content in nature after cellulose. It is rich in aromatic rings and has potential compatibility with hydrophobic pesticides, which can be used to encapsulate or load pesticides; contains polyphenol structure and various chromophoric groups, which can absorb ultraviolet rays and scavenge free radicals, and can be used as potential light stabilizing materials for the protection of photosensitive drugs; lignin is a natural polymer material with biodegradability, and the degradation products can fertilize the soil; the molecular structure contains functional groups such as aromatic groups, carboxyl groups and hydroxyl groups, which can be modified by amination, sulfonation and graft copolymerization of lignin, further improving the hydrophobicity, adhesion and light stability of lignin and its derivatives. Huang team successfully prepared a conjugate (AL-EB) by connecting methylamino avermectin with alkali lignin through amide bond. The anti-photolysis experiment shows that the photolysis half-life of AL-EB is 3.5 times that of ordinary methylamino avermectin suspension agent, and AL-EB has excellent anti-photolysis performance. Zhou team prepared nanometer microspheres by wrapping avermectin with acetylated lignin. After 50h of ultraviolet irradiation, the retention rate is 67.6%, which is significantly higher than that of the control group (27%), and also has a certain slow-release effect.

[0006] The above shows that lignin has good application in light-degradable formulations, but lignin is a three-dimensional network structure, and the content of long-chain alkyl in the structure is low, and the compatibility between lignin and liposoluble pesticides is poor, therefore, how to improve the compatibility between lignin and liposoluble pesticides for improving the anti-photolysis performance of pesticides needs to be solved. SUMMARY

[0007] In order to solve the defects and shortcomings of the prior art, the primary purpose of the present application is to provide a preparation method of lignin-polyether.

[0008] Another purpose of the present application is to provide lignin-polyether prepared by the above preparation method.

[0009] Still another purpose of the present application is to provide application of the above lignin-polyether as a carrier material in pesticide formulations.

[0010] Still another purpose of the present application is to provide a pesticide formulation and a preparation method thereof.

[0011] The present application first prepares an intermediate terminated by isocyanate, and then polymerizes with lignin to obtain lignin-polyether. The lignin-polyether prepared by the present application can be well self-dispersed in water, has good compatibility with hydrophobic pesticides, and has excellent ultraviolet resistance. The method specifically comprises the following steps: first, under a nitrogen atmosphere, reacting a hydroxyl-containing surfactant with isocyanate to obtain an intermediate terminated by isocyanate; and then, reacting the intermediate with the hydroxyl groups in alkali lignin to obtain lignin-polyether through nucleophilic substitution. The lignin-polyether is loaded with AVM and an ultraviolet absorber to obtain nanoscale microspheres, the average particle size of the microspheres is within 250 nm, the particle size changes by less than 5% after 2 weeks of heat storage, and the photolysis retention rate of the nanoscale microspheres is higher than 60% under ultraviolet lamp irradiation for 60 h, which is much higher than 16.96% of the commercial microemulsion.

[0012] To achieve the object of the present application, the present application adopts the following technical solutions:

[0013] In a first aspect, the present application provides a preparation method of lignin-polyether, comprising the following steps:

[0014] (1) reacting a hydroxyl-containing surfactant with isocyanate in the presence of a catalyst to obtain an intermediate;

[0015] (2) reacting the intermediate with lignin to obtain lignin-polyether after addition salt agent reaction.

[0016] The present application introduces a surfactant having good compatibility with the original drug into the lignin molecule by grafting modification of the lignin with a small-molecule surfactant containing terminal hydroxyl groups, so that the lignin-polyether obtained after modification can significantly improve the encapsulation rate of liposoluble original drugs.

[0017] Preferably, the hydroxyl-containing surfactant in step (1) comprises at least one of Triton, acetylene glycol polyether, lauryl alcohol polyoxyethylene ether and Tween; and further preferably comprises at least one of Triton X-114, tetramethyl acetylene glycol polyoxyethylene ether, dodecane acetylene glycol polyoxyethylene, lauryl alcohol polyoxyethylene ether, Tween 40, Tween 60 and Tween 80.

[0018] Preferably, the isocyanate in step (1) comprises at least one of toluene diisocyanate, diphenyl methane diisocyanate and isophorone diisocyanate, and further preferably comprises isophorone diisocyanate.

[0019] Preferably, the hydroxyl-containing surfactant is 1.55 to 10 parts by mass (e.g., 1.55 parts, 1.8 parts, 2.14 parts, 3.13 parts, 3.23 parts, 5.14 parts, 6.00 parts, 6.42 parts, 6.55 parts, 7 parts, 8 parts, 9 parts, 10 parts, etc.), the isocyanate is 1.5 to 3.5 parts (e.g., 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, etc.), and the lignin is 3 to 8 parts (e.g., 3 parts, 4.03 parts, 5 parts, 5.4 parts, 6 parts, 6.46 parts, 7 parts, 8 parts, etc.); further, the hydroxyl-containing surfactant is 1.55 to 6.55 parts, the isocyanate is 2 parts, and the lignin is 4 to 8 parts. Any other specific point values within the above numerical ranges can be selected, and it is not convenient to repeat them here.

[0020] Preferably, the catalyst in step (1) comprises at least one of N-methylmorpholine, triethylenediamine, and dibutyltin dilaurate; further preferably, it comprises dibutyltin dilaurate.

[0021] Preferably, the hydroxyl-containing surfactant in step (1) is 1.55 to 10 parts by mass (e.g., 1.55 parts, 1.8 parts, 2.14 parts, 3.13 parts, 3.23 parts, 5.14 parts, 6.00 parts, 6.42 parts, 6.55 parts, 7 parts, 8 parts, 9 parts, 10 parts, etc.), and the catalyst is 0.01 to 0.1 parts (e.g., 0.01 parts, 0.015 parts, 0.02 parts, 0.03 parts, 0.04 parts, 0.05 parts, 0.06 parts, 0.07 parts, 0.08 parts, 0.09 parts, 0.1 parts, etc.). Any other specific point values within the above numerical ranges can be selected, and it is not convenient to repeat them here.

[0022] Preferably, the reaction in step (1) is carried out under an inert gas atmosphere, which comprises at least one of nitrogen, argon, and helium.

[0023] Preferably, the reaction in step (1) is carried out at a temperature of 60 to 80°C (e.g., 60°C, 65°C, 70°C, 75°C, 80°C, etc.) for a time of 1 to 2.5 hours (1 hour, 1.5 hours, 2 hours, 2.5 hours, etc.). Any other specific point values within the above numerical ranges can be selected, and it is not convenient to repeat them here.

[0024] Preferably, the isocyanate in step (1) is added dropwise into the reaction system within 5 to 10 minutes (e.g., 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes, etc.). Any other specific point values within the above numerical ranges can be selected, and it is not convenient to repeat them here.

[0025] Preferably, the hydroxyl-containing surfactant in step (1) is treated by vacuum heating to remove water, the heating temperature is 120°C, the vacuum degree is not less than -0.9 MPa, and the time is 2 hours.

[0026] Preferably, the lignin in step (2) comprises alkali lignin purified by acid precipitation in black liquor of alkali pulping.

[0027] Preferably, the temperature for the reaction between the intermediate and the lignin in step (2) is 40-55℃ (e.g. 40℃, 45℃, 50℃, 55℃, etc.); the time is 2-3h (2h, 2.2h, 2.4h, 2.6h, 2.8h, 3h, etc.). Any other specific point value within the above numerical range can be selected, which is not repeated here.

[0028] Preferably, the salt forming agent in step (2) comprises triethylamine.

[0029] Preferably, the lignin in step (2) is 3-8 parts (e.g. 3 parts, 4.03 parts, 5 parts, 5.4 parts, 6 parts, 6.46 parts, 7 parts, 8 parts, etc.) and the salt forming agent is 0.6-1.6 parts (e.g. 0.6 parts, 0.8 parts, 1 part, 1.2 parts, 1.4 parts, 1.6 parts, etc.) by mass fraction. Any other specific point value within the above numerical range can be selected, which is not repeated here.

[0030] Preferably, the temperature for the reaction of the salt forming agent in step (2) is room temperature (e.g. 25-35℃, which can be 25℃, 28℃, 30℃, 32℃, 35℃, etc.) and the time is 10-40min (e.g. 10min, 15min, 20min, 25min, 30min, 35min, 40min, etc.). Any other specific point value within the above numerical range can be selected, which is not repeated here.

[0031] Preferably, the lignin in step (2) is dissolved in an organic solvent before reacting with the intermediate; the organic solvent comprises at least one of N,N-dimethylformamide, acetone and N,N-dimethylacetamide; the lignin is 3-8 parts (e.g. 3 parts, 4.03 parts, 5 parts, 5.4 parts, 6 parts, 6.46 parts, 7 parts, 8 parts, etc.) and the organic solvent is 20-53 parts (e.g. 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 53 parts, etc.) by mass fraction. Any other specific point value within the above numerical range can be selected, which is not repeated here.

[0032] Preferably, after the addition salt agent reaction of step (2), hot water and sodium chloride at 50-80℃ (e.g. 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, 80℃, etc.) are added to the obtained product solution, and hot water at 50-80℃ (e.g. 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, 80℃, etc.) is continuously added to the precipitated solid, and the operation (continuously adding hot water at 50-80℃ to the precipitated solid) is repeated 2-4 times to obtain the purified lignin-polyether. Any other specific point value within the above numerical range can be selected, which is not repeated here.

[0033] In a second aspect, the present application provides a lignin-polyether prepared by the above method.

[0034] In a third aspect, the present application provides the use of the above lignin-polyether as a carrier material in the preparation of a pesticide preparation.

[0035] The pesticide is a light-degradable pesticide, including at least one of abamectin, emamectin benzoate, spinosad and spinetoram.

[0036] In a fourth aspect, the present application provides a method for preparing a pesticide preparation, comprising the following steps:

[0037] The pesticide and the above lignin-polyether are dissolved in an organic solvent, and after stirring, water is added to obtain a pesticide preparation;

[0038] Alternatively, the pesticide, the above lignin-polyether and the ultraviolet absorber are dissolved in an organic solvent, and after stirring, water is added to obtain a pesticide preparation.

[0039] Due to the limited content of phenolic hydroxyl groups in lignin, the antioxidant activity is limited, and the ultraviolet absorber can be selectively added to absorb radiation energy, thereby improving the anti-photolysis performance of the pesticide.

[0040] The lignin-polyether of the present application can be used as a carrier material to prepare drug-loaded microspheres by self-assembly in an aqueous medium. The prepared nanoscale microspheres have a smaller particle size and better dispersion stability, with an average particle size D≤260nm and a dispersion coefficient PDI<0.3, and have a good protective effect on light-sensitive raw materials, with a photolysis retention rate >69.85% under 60h direct ultraviolet lamp irradiation.

[0041] Preferably, the pesticide is a light-degradable pesticide, including at least one of abamectin, emamectin benzoate, spinosad and spinetoram.

[0042] Preferably, the pesticide is 2-7 parts (for example, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, etc.), the lignin-polyether is 5-9 parts (for example, 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, 8.5 parts, 9 parts, etc.), or the pesticide is 2-7 parts (for example, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, etc.), the lignin-polyether is 5-9 parts (for example, 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, 8.5 parts, 9 parts, etc.), and the ultraviolet absorber is 1-3 parts (for example, 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, etc.). Any other specific point value within the above numerical range can be selected, and it is not convenient to repeat them here.

[0043] Preferably, the ultraviolet absorber includes at least one of avobenzone (AVB), oxybenzone (BP), and bis-ethylhexyloxyphenol methoxyphenyl triazine (BEMT).

[0044] Preferably, the organic solvent includes at least one of N,N-dimethylformamide, N-N-dimethylacetamide, and acetone; the pesticide is 2-7 parts (for example, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, etc.), and the organic solvent is 20-80 parts (for example, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, 75 parts, 80 parts, etc.). Any other specific point value within the above numerical range can be selected, and it is not convenient to repeat them here.

[0045] Preferably, the pesticide is 2-7 parts (for example, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, etc.), and the water is 140-180 parts (for example, 140 parts, 145 parts, 150 parts, 155 parts, 160 parts, 165 parts, 170 parts, 175 parts, 180 parts, etc.). Any other specific point value within the above numerical range can be selected, and it is not convenient to repeat them here.

[0046] In a fifth aspect, the present application provides a pesticide preparation prepared by the above preparation method.

[0047] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0048] 1. The present application uses natural high molecular material lignin as raw material and copolymerizes with hydroxyl-containing surfactant to obtain lignin-polyether, which has the characteristics of green environmental protection.

[0049] 2. The lignin-polyether of the present application has good dispersibility in water, good compatibility with hydrophobic pesticides, and excellent ultraviolet resistance.

[0050] 3. The lignin-polyether of the present application can be used as a carrier material to prepare drug-loaded microspheres by self-assembly in an aqueous medium. The prepared nanoscale microspheres have a small particle size and good dispersion stability, with an average particle size D≤260 nm and a dispersion coefficient PDI<0.3, and have a good protective effect on photosensitive raw materials, with a photolysis retention rate >69.85% under 60h direct irradiation of an ultraviolet lamp.

[0051] 4. The carrier material prepared by the present application using lignin as the main raw material is environmentally friendly. BRIEF DESCRIPTION OF DRAWINGS

[0052] Figure 1 The infrared spectra of the lignin-polyether A1 and B1 obtained in Examples 1 and 2.

[0053] Figure 2 The scanning electron micrographs of the microspheres prepared from the lignin-polyether A1 and abamectin obtained in Example 1 and the raw material.

[0054] Figure 3 The particle size change graphs of A1@AVM, B1@AVM, C1@AVM, C2@AVM, BP@AVM, AVB@AVM, BEMT@AVM, and ME after storage at 0℃, 55℃, and 25℃ for 14 days.

[0055] Figure 4 The TSI graphs of A1@AVM, B1@AVM, C1@AVM, C2@AVM, BP@AVM, AVB@AVM, BEMT@AVM, and ME.

[0056] Figure 5 The contact angles of A1@AVM, B1@AVM, C1@AVM, C2@AVM, BP@AVM, AVB@AVM, BEMT@AVM, and ME on pothos and paraffin surfaces.

[0057] Figure 6 The raw material retention rates of A1@AVM, B1@AVM, C1@AVM, C2@AVM, BP@AVM, AVB@AVM, BEMT@AVM, and ME after 60h irradiation of a 30W ultraviolet lamp.

[0058] Figure 7 The anti-rainwater scouring experiments of A1@AVM, B1@AVM, C1@AVM, C2@AVM, BP@AVM, AVB@AVM, BEMT@AVM, and ME. DETAILED DESCRIPTION

[0059] The present application will be further described in detail below in conjunction with the examples and drawings, but the embodiments of the present application are not limited thereto.

[0060] Unless otherwise indicated, the procedures in the examples were carried out under conventional conditions or those recommended by the manufacturer. The raw materials, reagents, etc. used, for which no manufacturer is indicated, are all conventional products that can be obtained commercially.

[0061] Example 1

[0062] A method for preparing a lignin-polyether, comprising the following steps:

[0063] (1) 5.14 parts by mass of polyethylene glycol p-isooctylphenyl ether (Triton X-114, Anhui Zesheng Co., Ltd.) was added to a flask, and vacuum drying was performed at -0.9 MPa and 120°C for 2 h to remove water. The temperature was lowered to 70°C, and nitrogen was introduced. 2 parts of isophorone diisocyanate (Anhui Zesheng Co., Ltd.) and 0.015 parts of dibutyltin dilaurate (Shanghai Aldrin Co., Ltd.) were added dropwise, and stirred uniformly. The dropwise addition was completed in 5 min, and the reaction was continued for 2 h to obtain an intermediate capped with isophorone.

[0064] (2) 5.4 parts by mass of alkali lignin and 40 parts of N,N-dimethylformamide (Shanghai Maikelin Biochemical Technology Co., Ltd.) were added to a flask, and heated to 45°C. The alkali lignin was dissolved by stirring. Nitrogen was introduced, and 7.14 parts of the intermediate prepared in step (1) was added. The reaction was continued for 3 h, and the temperature was lowered to 30°C. 1 part of triethylamine (Damao Chemical Reagent Co., Ltd.) was added, and the reaction was continued for 30 min to obtain a product. Hot water at 80°C and sodium chloride were added to the product solution, and the precipitate was removed by filtration. The solid precipitate was further heated with water, and the precipitate was removed by filtration. This operation was repeated three times to obtain a purified lignin-polyether product. The lignin-polyether obtained in this example 1 was designated as A1.

[0065] The average particle size of the lignin-polyether A1 in this example was 113 nm, the PDI was 0.213, and the phenolic hydroxyl content was 0.722 mmol / g.

[0066] Example 2

[0067] A method for preparing a lignin-polyether, comprising the following steps:

[0068] (1) 5.14 parts by mass of polyethylene glycol p-isooctylphenyl ether (Triton X-114, Anhui Zesheng Co., Ltd.) was added to a flask, and vacuum drying was performed at -0.9 MPa and 120°C for 2 h to remove water. The temperature was lowered to 70°C, and nitrogen was introduced. 2 parts of isophorone diisocyanate (Anhui Zesheng Co., Ltd.) and 0.015 parts of dibutyltin dilaurate (Shanghai Aldrin Co., Ltd.) were added dropwise, and stirred uniformly. The dropwise addition was completed in 5 min, and the reaction was continued for 2 h to obtain an intermediate capped with isophorone.

[0069] (2) 5.4 parts of alkali lignin and 40 parts of N,N-dimethylformamide were added into a flask, heated to 45°C, and stirred to dissolve the alkali lignin. Nitrogen was then introduced, 7.14 parts of the intermediate prepared in step (1) was added, and reacted for 3 hours. The temperature was lowered to 30°C, 1 part of triethylamine was added, and reacted for 30 minutes to obtain the product. Hot water at 80°C and sodium chloride were added into the product solution, and the precipitate was filtered out. The solid precipitate was heated with water, and the precipitate was filtered out. This operation was repeated three times to obtain the purified lignin-polyether product. The lignin-polyether product obtained in this example 2 was named as B1.

[0070] In this example, the average particle size of the lignin-polyether B1 was 53 nm, the PDI was 0.240, and the phenolic hydroxyl content was 0.776 mmol / g.

[0071] Example 3

[0072] A method for preparing a lignin-polyether, comprising the following steps:

[0073] (1) 1.55 parts of dodecyne glycol polyoxyethylene (Surfynol 440, Jiangsu Hai'an Petrochemical Co., Ltd.) was added into a flask, vacuum dried at -0.9 MPa and 120°C for 2 hours, and the temperature was lowered to 70°C. Nitrogen was introduced, 2 parts of isofuroone diisocyanate and 0.015 parts of dibutyltin dilaurate were added, stirred uniformly, and 5 minutes later, the dropwise addition was completed. The reaction was carried out for 2 hours to obtain an intermediate capped with isofuroone.

[0074] (2) 5.4 parts of alkali lignin and 40 parts of N,N-dimethylformamide were added into a flask, heated to 45°C, and stirred to dissolve the alkali lignin. Nitrogen was then introduced, 3.15 parts of the intermediate prepared in step (1) was added, and reacted for 3 hours. The temperature was lowered to 30°C, 1 part of triethylamine was added, and reacted for 30 minutes to obtain the product. Hot water at 80°C and sodium chloride were added into the product solution, and the precipitate was filtered out. The solid precipitate was heated with water, and the precipitate was filtered out. This operation was repeated three times to obtain the purified lignin-polyether product. The lignin-polyether product obtained in this example 3 was named as B2.

[0075] In this example, the average particle size of the lignin-polyether B2 was 67 nm, the PDI was 0.192, and the phenolic hydroxyl content was 0.890 mmol / g.

[0076] Example 4

[0077] A method for preparing a lignin-polyether, comprising the following steps:

[0078] (1) In a three-necked flask, 6.00 parts of lauryl alcohol polyoxyethylene ether (AEO7, Anhui Zesheng Co., Ltd.) was added, vacuum dried at -0.9 MPa and 120°C for 2 h, cooled to 70°C, and then nitrogen was bubbled through. 2 parts of isophorone diisocyanate and 0.015 parts of dibutyltin dilaurate were added dropwise, stirred uniformly, and the dropwise addition was completed in 5 min. The reaction was carried out for 2 h to obtain an intermediate capped with isophorone.

[0079] (2) In a three-necked flask, 5.4 parts of alkali lignin and 40 parts of N,N-dimethylformamide were added, heated to 45°C, and the alkali lignin was stirred to dissolve completely. Then nitrogen was bubbled through, 8.00 parts of the intermediate prepared in step (1) was added, and the reaction was carried out for 3 h. The temperature was lowered to 30°C, 1 part of triethylamine was added, and the reaction was carried out for 30 min to obtain the product. Hot water at 80°C and sodium chloride were added to the product solution, and the precipitate was removed by filtration. The solid precipitate was further heated with water, and the precipitate was removed by filtration. This operation was repeated three times to obtain the purified lignin-polyether product. The lignin-polyether obtained in this example 4 was named B3.

[0080] The average particle size of the lignin-polyether B3 obtained in this example was 77 nm, the PDI was 0.165, and the phenolic hydroxyl content was 0.752 mmol / g.

[0081] Example 5

[0082] A method for preparing a lignin-polyether, comprising the following steps:

[0083] (1) In a three-necked flask, 1.8 parts of lauryl alcohol polyoxyethylene ether (Peregal O-20, Shanghai Maikelin Biochemical Technology Co., Ltd.) was added, vacuum dried at -0.9 MPa and 120°C for 2 h, cooled to 70°C, and then nitrogen was bubbled through. 2 parts of isophorone diisocyanate and 0.015 parts of dibutyltin dilaurate were added dropwise, stirred uniformly, and the dropwise addition was completed in 5 min. The reaction was carried out for 2 h to obtain an intermediate capped with isophorone.

[0084] (2) In a three-necked flask, 5.4 parts of alkali lignin and 40 parts of N,N-dimethylformamide were added, heated to 45°C, and the alkali lignin was stirred to dissolve completely. Then nitrogen was bubbled through, 3.8 parts of the intermediate prepared in step (1) was added, and the reaction was carried out for 3 h. The temperature was lowered to 30°C, 1 part of triethylamine was added, and the reaction was carried out for 30 min to obtain the product. Hot water at 80°C and sodium chloride were added to the product solution, and the precipitate was removed by filtration. The solid precipitate was further heated with water, and the precipitate was removed by filtration. This operation was repeated three times to obtain the purified lignin-polyether product. The lignin-polyether obtained in this example 5 was named B4.

[0085] The average particle size of the lignin-polyether B4 in this example is 102 nm, the PDI is 0.179, and the phenolic hydroxyl content is 0.922 mmol / g.

[0086] Example 6

[0087] A method for preparing a lignin-polyether, comprising the following steps:

[0088] (1) In terms of mass fraction, 3.13 parts of lauryl alcohol polyoxyethylene ether (AEO9, Anhui Zesheng Co., Ltd.) is added to a three-necked flask, vacuum drying at -0.9 MPa and 120°C for 2 h to remove water, and then cooled to 70°C and purged with nitrogen. 2 parts of isoflurone diisocyanate and 0.015 parts of dibutyltin dilaurate are added dropwise and stirred uniformly, and the dropwise addition is completed in 5 min. After 2 h of reaction, an intermediate capped with isoflurone is obtained.

[0089] (2) In terms of mass fraction, 5.4 parts of alkali lignin and 40 parts of N,N-dimethylformamide are added to a three-necked flask, heated to 45°C, and stirred to fully dissolve the alkali lignin. Then purged with nitrogen, 5.13 parts of the intermediate prepared in step (1) is added, and reacted for 3 h. After cooling to 30°C, 1 part of triethylamine is added, and reacted for 30 min to obtain the product. Hot water at 80°C and sodium chloride are added to the product solution, and the precipitate is removed by filtration. The solid precipitate is further heated with water, and the precipitate is removed by filtration. This operation is repeated 3 times to obtain the purified lignin-polyether product. The lignin-polyether obtained in this example 6 is named B5.

[0090] The average particle size of the lignin-polyether B5 in this example is 128 nm, the PDI is 0.286, and the phenolic hydroxyl content is 0.827 mmol / g.

[0091] Example 7

[0092] A method for preparing a lignin-polyether, comprising the following steps:

[0093] (1) In terms of mass fraction, 3.13 parts of lauryl alcohol polyoxyethylene ether (AEO9, Anhui Zesheng Co., Ltd.) is added to a three-necked flask, vacuum drying at -0.9 MPa and 120°C for 2 h to remove water, and then cooled to 70°C and purged with nitrogen. 2 parts of isoflurone diisocyanate and 0.015 parts of dibutyltin dilaurate are added dropwise and stirred uniformly, and the dropwise addition is completed in 5 min. After 2 h of reaction, an intermediate capped with isoflurone is obtained.

[0094] (2) 8 parts of alkali lignin and 40 parts of N,N-dimethylformamide were added into a flask, heated to 45°C, and stirred to dissolve the alkali lignin. Nitrogen was then introduced, 8.42 parts of the intermediate prepared in step (1) was added, and reacted for 3 hours. The temperature was then lowered to 30°C, 1 part of triethylamine was added, and reacted for 30 minutes to obtain the product. Hot water at 80°C and sodium chloride were added into the product solution, and the precipitate was filtered out. The solid precipitate was heated with water, and the precipitate was filtered out. This process was repeated three times to obtain the purified lignin-polyether product. The lignin-polyether obtained in this example 8 was named B7.

[0095] In this example, the average particle size of the lignin-polyether B7 was 165 nm, the PDI was 0.275, and the phenolic hydroxyl content was 0.926 mmol / g.

[0096] Example 8

[0097] A method for preparing a lignin-polyether, comprising the following steps:

[0098] (1) 6.42 parts of polyoxyethylene sorbitan monopalmitate (Tween 40, Shanghai Maikelin Biochemical Technology Co., Ltd.) was added into a flask, and vacuum dried at -0.9 MPa and 120°C for 2 hours to remove water. The temperature was then lowered to 70°C, and nitrogen was introduced. 2 parts of isoflurone diisocyanate and 0.015 parts of dibutyltin dilaurate were added dropwise, and stirred uniformly. The dropwise addition was completed in 5 minutes, and reacted for 2 hours to obtain an intermediate capped with isoflurone.

[0099] (2) 8 parts of alkali lignin and 40 parts of N,N-dimethylformamide were added into a flask, heated to 45°C, and stirred to dissolve the alkali lignin. Nitrogen was then introduced, 8.42 parts of the intermediate prepared in step (1) was added, and reacted for 3 hours. The temperature was then lowered to 30°C, 1 part of triethylamine was added, and reacted for 30 minutes to obtain the product. Hot water at 80°C and sodium chloride were added into the product solution, and the precipitate was filtered out. The solid precipitate was heated with water, and the precipitate was filtered out. This process was repeated three times to obtain the purified lignin-polyether product. The lignin-polyether obtained in this example 8 was named B7.

[0100] In this example, the average particle size of the lignin-polyether B7 was 165 nm, the PDI was 0.275, and the phenolic hydroxyl content was 0.926 mmol / g.

[0101] Example 9

[0102] A method for preparing a lignin-polyether, comprising the following steps:

[0103] (1) In a three-necked flask, 2.14 parts of polyoxyethylene sorbitan monooleate (Tween 80, Shanghai Maikelin Biochemical Technology Co., Ltd.) was added, and vacuum drying was performed at -0.9 MPa and 120°C for 2 h to remove water. The temperature was lowered to 70°C, and nitrogen was introduced. 2 parts of isophorone diisocyanate and 0.015 parts of dibutyltin dilaurate were added dropwise, and stirring was performed for 5 min. The dropwise addition was completed, and the reaction was performed for 2 h to obtain an intermediate capped with isophorone.

[0104] (2) In a three-necked flask, 6.46 parts of alkali lignin and 40 parts of N,N-dimethylformamide were added, and heating was performed to 45°C. Stirring was performed to dissolve the alkali lignin. Nitrogen was introduced, 4.14 parts of the intermediate prepared in step (1) was added, and the reaction was performed for 3 h. The temperature was lowered to 30°C, 1 part of triethylamine was added, and the reaction was performed for 30 min to obtain a product. Hot water at 80°C and sodium chloride were added to the product solution, and the precipitate was removed by filtration. Water was continuously added to the solid precipitate, and the precipitate was removed by filtration. The operation was repeated three times to obtain a purified lignin-polyether product. The lignin-polyether obtained in this example 9 was named B8.

[0105] In this example, the average particle size of the lignin-polyether B8 was 153 nm, the PDI was 0.341, and the phenolic hydroxyl content was 0.792 mmol / g.

[0106] Example 10

[0107] A method for preparing a lignin-polyether includes the following steps:

[0108] (1) In a three-necked flask, 3.23 parts of polyethylene glycol mono(tert-octylphenyl) ether (Triton X-100, Anhui Zesheng Co., Ltd.) was added, and vacuum drying was performed at -0.9 MPa and 120°C for 2 h to remove water. The temperature was lowered to 70°C, and nitrogen was introduced. 2 parts of isophorone diisocyanate and 0.015 parts of dibutyltin dilaurate were added dropwise, and stirring was performed for 5 min. The dropwise addition was completed, and the reaction was performed for 2 h to obtain an intermediate capped with isophorone.

[0109] (2) In a three-necked flask, 4.03 parts of alkali lignin and 40 parts of N,N-dimethylformamide were added, and heating was performed to 45°C. Stirring was performed to dissolve the alkali lignin. Nitrogen was introduced, 5.23 parts of the intermediate prepared in step (1) was added, and the reaction was performed for 3 h. The temperature was lowered to 30°C, 1 part of triethylamine was added, and the reaction was performed for 30 min to obtain a product. Hot water at 80°C and sodium chloride were added to the product solution, and the precipitate was removed by filtration. Water was continuously added to the solid precipitate, and the precipitate was removed by filtration. The operation was repeated three times to obtain a purified lignin-polyether product. The lignin-polyether obtained in this example 10 was named B9.

[0110] The average particle size of the lignin-polyether B9 in this example is 133 nm, the PDI is 0.309, and the phenolic hydroxyl content is 0.765 mmol / g.

[0111] Comparative Example 1

[0112] A method for preparing a lignin-polyether, comprising the following steps:

[0113] (1) 10 parts of polyethylene glycol (Mn 2000, Anhui Zesheng Co., Ltd.) is added to a three-necked flask, and vacuum drying is performed at -0.9 MPa and 120°C for 2 h to remove water. The temperature is lowered to 70°C, and nitrogen is introduced. 2 parts of isoflurone diisocyanate and 0.015 parts of dibutyltin dilaurate are added dropwise, and stirred uniformly. The dropwise addition is completed in 5 min, and the reaction is performed for 2 h to obtain an intermediate capped with isoflurone.

[0114] (2) 5.4 parts of alkali lignin and 40 parts of N,N-dimethylformamide are added to a three-necked flask, and heated to 45°C. The alkali lignin is stirred to be fully dissolved. Then nitrogen is introduced, and 7.14 parts of the intermediate prepared in step (1) is added. The reaction is performed for 3 h, the temperature is lowered to 30°C, and 1 part of triethylamine is added. The reaction is performed for 30 min to obtain a product. Hot water and sodium chloride are added to the product solution, and the precipitate is removed by filtration. The water is continuously added to the solid precipitate, and the precipitate is removed by filtration. This operation is repeated for 3 times to obtain a purified lignin-polyether product. The lignin-polyether obtained in Example 1 is named as C1.

[0115] The average particle size of the lignin-polyether C1 in this example is 146 nm, the PDI is 0.219, and the phenolic hydroxyl content is 0.821 mmol / g.

[0116] Comparative Example 2

[0117] A method for preparing a lignin-polyether, comprising the following steps:

[0118] (1) 5.5 parts of polypropylene glycol (Mn 1100, Anhui Zesheng Co., Ltd.) is added to a three-necked flask, and vacuum drying is performed at -0.9 MPa and 120°C for 2 h to remove water. The temperature is lowered to 70°C, and nitrogen is introduced. 2 parts of isoflurone diisocyanate and 0.015 parts of dibutyltin dilaurate are added dropwise, and stirred uniformly. The dropwise addition is completed in 5 min, and the reaction is performed for 2 h to obtain an intermediate capped with isoflurone.

[0119] (2) By mass, 5.4 parts of alkali lignin and 40 parts of N,N-dimethylformyl were added to a three-necked flask, heated to 45°C, and stirred until the alkali lignin was fully dissolved. Nitrogen gas was then introduced, followed by the addition of 7.2 parts of the intermediate prepared in step (1). The reaction was allowed to proceed for 3 hours, then cooled to 30°C, and 1 part of triethylamine was added. The reaction was allowed to proceed for 30 minutes to obtain the product. Hot water at 80°C and sodium chloride were added to the product solution, and the precipitate was removed by filtration. Water was then heated in the solid precipitate, and the precipitate was removed by filtration. This process was repeated three times to obtain the purified lignin-polyether product. The lignin-polyether obtained in Example 1 was named C2.

[0120] In this embodiment, the average particle size of lignin-polyether C2 is 233 nm, the PDI is 0.262, and the phenolic hydroxyl content is 0.789 mmol / g.

[0121] Infrared spectroscopy analysis was performed on the purified products A1 and B1 obtained from the reactions in Examples 1 and 2, with alkali lignin (AL) as a control. The results are as follows: Figure 1 As shown. From Figure 1 It can be seen that it is 1089cm -1 The characteristic absorption peaks of ether bonds (CO) appeared, A1 and B1 at 1665 cm⁻¹. -1 The stretching vibration peak of (C=O) in urethane esters appeared at 1512 cm⁻¹. -1 and 1458cm -1 The stretching vibration peak of the benzene ring was significantly enhanced at 2245 cm⁻¹, with B1 at this peak. -1 The appearance of the C≡C stretching vibration peak at this point proves that Triton and acetylenic diol were successfully grafted into the lignin molecule.

[0122] The particle size and zeta potential of the prepared A1, B1, C1 and C2 were tested, and the phenolic hydroxyl content was determined by the Folin-Ciocalteu method and the carboxyl content was determined by automatic potentiometric titration. The results are shown in Table 1.

[0123] Table 1 Test Results for A1, B1, C1, and C2

[0124]

[0125] As can be seen from Table 1, the particle size of B1 is 53 nm, which is smaller than 133 nm of A1, and the absolute value of Zeta potential of B1 and A1 is greater than 30 mV, indicating that A1 and B1 can be stably dispersed in water, and the stability of B1 is better than that of A1. This is mainly because the alkyne diol grafted by B1 has stronger surface activity than the curdlan surfactant grafted by A1, the steric hindrance of both ends of the molecule is smaller, and B1 contains more carboxyl groups, so that the surface charge of the particles increases after ionization, which is beneficial to improve the stability of B1. Compared with the comparative samples C1 and C2, the lignin-polyether grafted with surfactant active agent exhibits better dispersibility in water. The phenolic hydroxyl content of the four lignin-polyethers is higher than 0.72 mmol / g.

[0126] The photosensitive raw material avermectin (AVM) was selected as the raw material for coating, and the ultraviolet absorbers were selected from o-hydroxybenzophenone (BP, Anhui Zesheng Co., Ltd.), avobenzone (AVB, Anhui Zesheng Co., Ltd.), and bis-ethylhexyloxyphenol methoxybenzotriazine (BEMT, Anhui Zesheng Co., Ltd.). A1, B1, C1 and C2 were selected as carrier materials to prepare 2wt% avermectin drug-loaded microspheres. The commonly used avermectin microemulsion on the market (purchased from Shenzhen Nuopixin Agricultural Co., Ltd.) was selected as the control group.

[0127] The preparation process of the nanometer microspheres is as follows:

[0128] In mass fraction, 8 parts of N,N-dimethylformamide were used to dissolve 0.5 parts of AVM and 0.6 parts of A1 or B1 or C1 or C2. Under magnetic stirring at 500 rpm and 30°C, 16 parts of water were added dropwise within 10 min to obtain an avermectin nanometer microsphere preparation, which was named A1@AVM, B1@AVM, C1@AVM and C2@AVM.

[0129] In mass fraction, 8 parts of N,N-dimethylformamide were used to dissolve 0.5 parts of AVM, 0.6 parts of A1 and 0.2 parts of AVB or BP or BEMT. Under magnetic stirring at 500 rpm and 30°C, 16 parts of water were added dropwise within 10 min to obtain an avermectin nanometer microsphere preparation, which was named AVB@AVM, BP@AVM and BEMT@AVM.

[0130] The scanning electron microscope was used to observe the micro-morphology of the nanometer microspheres A1@AVM (b, c) and AVM (a), and the results are shown in Figure 2 As can be seen from (a) in Figure 2 , AVM appears as crystal particles of different sizes under the electron microscope. In (b) and (c) in Figure 2 , no crystal particles are observed, indicating that the raw material is successfully coated into the microspheres, and the size of the microspheres is uniform, and the appearance is nanometer spherical.

[0131] The particle size changes of the seven prepared nanosphere formulations and the commercial microemulsion ME were measured after being diluted 100-fold with deionized water at 55℃, 0℃, 25℃, and 14 days. The results are as follows. Figure 3 As shown. By Figure 3 It was found that the average particle size change of different drug-loaded microspheres after 14 days of storage was less than 5%, and the addition of ultraviolet absorbers had almost no effect on the particle size change after heat storage. However, the commercial microemulsion ME increased in average particle size to 275 nm, 306 nm, and 436 nm after 14 days of storage at 25 °C, 0 °C, and 55 °C, respectively. This is because Brownian motion of molecules intensifies at high temperatures, leading to more frequent collisions between particles and thus an increase in particle size. The microspheres have a small amount of charge on their surface, which reduces collisions. Furthermore, the relatively small particle size of the microspheres (B1@AVM, BP@AVM, AVB@AVM, BEMT@AVM <150nm) allows for particle-driven motion, resisting gravity and achieving uniform dispersion in water. However, C1@AVM and C2@AVM have larger particle sizes, exceeding 250nm. This is mainly because C1 only incorporates PEG, exhibiting strong hydrophilicity, but with less AVM encapsulation. Compared to A1 and B1, more AVM remains free in the water, leading to a larger particle size. C2 only grafts highly hydrophobic PPG, resulting in poor hydrophilicity and a larger particle size. The dispersion stability of the seven nanospheres and ME was tested, and the results are as follows: Figure 4 As shown. By Figure 4 It can be seen that after 2 hours, the TSI values ​​from largest to smallest are C2@AVM, C1@AVM, AVB@AVM, A1@AVM, ME, B1@AVM, BP@AVM, and BEMT@AVM. C2@AVM and C1@AVM, due to their particle size greater than 250 nm, are more prone to precipitation and aggregation, resulting in poor dispersion stability. B1 and A1, in addition to providing PEG to improve the hydrophilicity of the carrier material, also provide hydrophobic groups to encapsulate more of the active ingredient, resulting in better dispersion stability. Furthermore, the addition of hydrophobic BP and BEMT helps to enhance the interaction between the carrier, the UV absorber, and AVM, thereby further improving the dispersion stability of the nanospheres. However, excessive hydrophobicity can hinder encapsulation, causing the nanospheres to remain free in the water, thus leading to a decrease in dispersion stability.

[0132] Contact angles of different nano-formulations, commercial microemulsion ME, and pure water were measured by adding them to the surfaces of pothos and paraffin. The results were obtained by... Figure 5 As shown. By Figure 5It can be seen that ME has the smallest contact angle on paraffin and pothos surfaces. This is because ME uses a large amount of surfactant. The nano-formulation after the microspheres are uniformly dispersed in water has a certain degree of surface activity due to the presence of hydrophobic benzene rings and hydrophilic carboxyl groups and polyether in the lignin-polyether. B1@AVM has the smallest contact angles of 22.85° and 58.89° on pothos and paraffin surfaces, respectively. The paraffin surface is more hydrophobic than the pothos surface, and the contact angle of the same formulation on the paraffin surface is larger than that on the pothos surface. However, the variation law of contact angle of different nano-formulations on the pothos surface is basically consistent with that on the paraffin surface. The contact angles of AVB@AVM, BEMT@AVM, and BP@AVM are almost the same as those of B1@AVM, indicating that the contact angle of the nanospheres is mainly determined by the carrier material. The UV absorber and AVM encapsulation inside the microspheres have almost no effect on the contact angle.

[0133] The retention rates of avermectin in seven nano-formulations and the commercial microemulsion ME were tested after 60 hours of irradiation with a 30W UV lamp. The results are as follows: Figure 6 As shown. By Figure 6 It was found that, compared to the 16.96% retention rate of the commercial microemulsion ME after 60 h, the retention rates of A1@AVM and B1@AVM were 69.85% and 71.71%, respectively, which were 4.12 to 4.23 times that of ME. C1@AVM and C2@AVM achieved retention rates of 58.19% and 66.27%, respectively. The addition of UV absorbers can further improve the retention rate. After AVM is encapsulated inside the microspheres, the shell structure reduces the impact of direct UV radiation on AVM. Furthermore, the phenolic hydroxyl groups and chromophores in lignin can absorb ultraviolet light and neutralize free radicals, effectively improving the stability of the nano-formulation. The lipid-soluble UV absorbers, after being encapsulated inside the microspheres, can absorb the radiation energy irradiated into the microspheres and convert it into heat energy, further improving the retention rate of AVM.

[0134] Different formulations (200 μL each) were applied to the surface of *Epipremnum aureum*. After drying, the leaves were rinsed with a peristaltic pump at 3 mL / min for 10 min. The residue of the original drug on the leaves was then extracted and compared with that before rinsing. The results are as follows: Figure 7 As shown. From Figure 7 It is evident that the residual amount of nanospheres on the leaves is significantly higher than that of microemulsions. This is mainly because ME exists in the form of micelles in water, and the process of drying and forming a film on the leaf surface can cause surfactants to re-aggregate, causing coagulation or crystallization and destroying their stability. Furthermore, the low surface tension and excessive wettability result in weak adhesion between the film and the leaf surface, making it easier for rainwater to carry away the active ingredients. The three-dimensional rigid structure of lignin itself and the cross-linked network formed by the reaction of hydroxyl groups and isocyanates on lignin can still maintain its microsphere structure after water evaporation, reducing the structural damage caused by AVM crystallization. The interaction between polar groups on the lignin surface promotes strong hydrogen bonds between the microspheres and the pothos, thereby improving the adhesion of the microspheres to the pothos surface.

[0135] The lignin-polyether prepared in the application is used as a carrier material to load abamectin and ultraviolet absorbers to prepare nanoscale microspheres. Under scanning electron microscope observation, the carrier material presents spherical shape after loading the raw drug, and the size is uniform. After storing different formulations for 14 days, the average particle size change rate is less than 5%, and better dispersion stability is also exhibited. The anti-photolysis performance test shows that the photolysis retention rate of the nanoscale microspheres after 60h is more than 60%, which is much higher than 16.96% of the commercial microemulsion, and the anti-photolysis of the lignin-polyether grafted with hydroxyl surfactant is also better than that of the traditional lignin-polyether grafted with polyethylene glycol and polypropylene glycol. The contact angles of different formulations on pothos and paraffin are tested, and it is found that the nanoscale formulations have certain wetting effect, and the wetting effect of the nanoscale formulation prepared by the carrier material modified by the gemini surfactant is more obvious. And the nanoscale microspheres exhibit higher residual amount in the rainwater scouring experiment, and more accurately act on the plants. The nanoscale microspheres prepared by the lignin-polyether in the application can keep dispersion stability for a long time, prolong the photolysis half-life of the raw drug, and have the potential for industrial application.

[0136] The above examples are the preferred embodiments of the application, but the embodiments of the application are not limited by the above examples, and any changes, modifications, substitutions, combinations, simplifications made without departing from the spirit and principles of the application should be equivalent replacement methods, and are all included in the protection scope of the application.

Claims

1. A process for the preparation of a lignin-polyether, characterized in that, The method comprises the following steps: (1) reacting a hydroxyl-containing surfactant with an isocyanate in the presence of a catalyst to obtain an intermediate; (2) reacting the intermediate with lignin and then adding a salt agent to obtain a lignin-polyether.

2. The preparation method according to claim 1, characterized in that, The hydroxyl-containing surfactant in step (1) comprises at least one of Triton, acetylenic diol polyether, lauryl alcohol polyoxyethylene ether and Tween; further preferably, it comprises at least one of Triton X-114, tetramethyl acetylenic diol polyoxyethylene ether, dodecyl acetylenic diol polyoxyethylene, lauryl alcohol polyoxyethylene ether, Tween 40, Tween 60 and Tween 80; and / or, the isocyanate in step (1) comprises at least one of toluene diisocyanate, diphenyl methane diisocyanate and isophorone diisocyanate; further preferably, it comprises isophorone diisocyanate; and / or, the hydroxyl-containing surfactant is 1.55-10 parts by mass and the isocyanate is 1.5-3.5 parts by mass; further, the hydroxyl-containing surfactant is 1.55-6.55 parts by mass and the isocyanate is 2 parts by mass; and / or, the reaction in step (1) is carried out at a temperature of 60-80℃ for 1-2.5 hours; and / or, the reaction in step (1) is carried out in an inert gas atmosphere, wherein the inert gas comprises at least one of nitrogen, argon and helium.

3. The method of claim 1 or 2, wherein the method further comprises, The lignin in step (2) comprises alkali lignin obtained by acid precipitation from black liquor of alkali pulping; and / or, the hydroxyl-containing surfactant is 1.55-10 parts by mass and the lignin is 3-8 parts by mass; further, the hydroxyl-containing surfactant is 1.55-6.55 parts by mass and the lignin is 4-8 parts by mass; and / or, the reaction of the intermediate with the lignin in step (2) is carried out at a temperature of 40-55℃ for 2-3 hours.

4. The method of claim 1 or 2, wherein the method is carried out at a temperature of from 20 to 100°C. The catalyst in step (1) comprises at least one of N-methyl morpholine, triethylenediamine and dibutyl tin dilaurate; further preferably, it comprises dibutyl tin dilaurate; and / or, the hydroxyl-containing surfactant in step (1) is 1.55-10 parts by mass and the catalyst is 0.01-0.1 parts by mass; and / or, the salt agent in step (2) comprises triethylamine; and / or, the lignin in step (2) is 3-8 parts by mass and the salt agent is 0.6-1.6 parts by mass; and / or, the reaction of the salt agent in step (2) is carried out at a temperature of 25-35℃ for 10-40 minutes; and / or, the lignin in step (2) is first dissolved in an organic solvent and then reacted with the intermediate; the organic solvent comprises at least one of N,N-dimethylformamide, acetone and N,N-dimethylacetamide; the lignin is 3-8 parts by mass and the organic solvent is 20-53 parts by mass.

5. A lignin-polyether prepared by the method of any one of claims 1-4.

6. Use of the lignin-polyether of claim 5 as a carrier material in preparation of a pesticide preparation.

7. Use according to claim 6, characterized in that, The pesticide is a light-degradable pesticide, which comprises at least one of abamectin, emamectin benzoate, spinosad and spinetoram.

8. The present application provides a method for producing a pesticide preparation, characterized by, The method comprises the following steps: dissolving the pesticide and the lignin-polyether of claim 5 in an organic solvent, stirring and then mixing with water to obtain the pesticide preparation. Or, the pesticide, the lignin-polyether of claim 5 and the ultraviolet absorber are dissolved in an organic solvent, mixed by adding water after stirring to obtain a pesticide preparation.

9. The preparation method according to claim 8, characterized in that, The pesticide is a light-degradable pesticide, and includes at least one of abamectin, emamectin benzoate, spinosad and spinetoram; And / or, the pesticide is 2-7 parts by mass, the lignin-polyether is 5-9 parts by mass, or the pesticide is 2-7 parts by mass, the lignin-polyether is 5-9 parts by mass, and the ultraviolet absorber is 1-3 parts by mass; And / or, the ultraviolet absorber includes at least one of avobenzone, oxybenzone and bis-ethylhexyloxyphenol methoxyphenyl triazine; And / or, the organic solvent is at least one of N,N-dimethylformamide, N-N-dimethylacetamide and acetone; the pesticide is 2-7 parts by mass, and the organic solvent is 20-80 parts by mass; And / or, the pesticide is 2-7 parts by mass, and the water is 140-180 parts by mass.

10. A pesticide preparation prepared by the preparation method of any one of claims 8-9.

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