Hexazinone-containing herbicide and preparation method thereof

Abstract

The invention discloses a hexazinone-containing herbicide and a preparation method thereof, and belongs to the technical field of pesticides. The preparation method comprises the following steps: S1, preparing PEI / CS; and S2, uniformly mixing Tween-80 with a PEI / CS solution, dispersing hexazinone in DMF for ultrasonic dissolution, slowly dropwise adding the hexazinone solution into the PEI / CS solution under a magnetic stirring condition, carrying out a reaction for 30 min to obtain PEI / CS / hexazinone, dropwise adding a 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate solution into the PEI / CS / hexazinone, carrying out a stirring reaction for 30 min, and carrying out centrifugation, washing and drying to obtain the hexazinone-containing herbicide. The final product obtained by the method has high load rate, slow release stability and photodegradation resistance, the preparation efficiency is high, and the process is simple and controllable.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of pesticides, in particular to a kind of herbicide containing hexazinone and preparation method thereof. BACKGROUND

[0002] Hexazinone, English name: Hexazinone (CAS No.51235-04-2), Chinese name: 3-cyclohexyl-6-dimethylamino-1-methyl-1,3,5-triazine-2,4-dione. Hexazinone is a high-efficiency universal triazine herbicide. Hexazinone mainly inhibits photosynthesis of plants, and plants can absorb hexazinone from roots and leaves, and conduct through xylem, causing metabolic disorder and death, which can prevent and control annual and perennial weeds and woody plants, etc. It is active for foliar treatment or soil treatment by root absorption.

[0003] Hexazinone is widely used in the field of pesticides, but its large-scale use leads to serious environmental residues, causing serious pollution to the environment. In order to solve these problems, improve the utilization rate of pesticides and its sustained effective time, it is necessary to use drug-loaded control / sustained-release carrier to control the release of pesticides, reduce the use amount of pesticides, and achieve the purpose of small amount and high efficiency. SUMMARY

[0004] The present application provides a kind of herbicide containing hexazinone and preparation method thereof, which can solve the problem that hexazinone is widely used in the field of pesticides in the prior art, but its large-scale use leads to serious environmental residues, causing serious pollution to the environment.

[0005] The purpose of the present application can be achieved by the following technical solutions: In a first aspect, the present application provides a preparation method of a herbicide containing hexazinone, comprising the following steps: S1, preparing PEI / CS; S2, mixing emulsifier Tween-80 with PEI / CS solution, then dispersing hexazinone in DMF and ultrasonic dissolving, then slowly dropping hexazinone solution into PEI / CS solution under magnetic stirring for 30 min to obtain PEI / CS / hexazinone, then dropping 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate solution into PEI / CS / hexazinone and stirring for 30 min, centrifuging, washing, drying to obtain a herbicide containing hexazinone.

[0006] Further, the specific steps of step S1 are: S11, adding CS into 0.3 mol / L sodium periodate solution, reacting at 30℃ for 2-3 hours under nitrogen protection and in dark, adding ethylene glycol solution to terminate the reaction, standing, filtering, adding acetone into the filtrate, performing suction filtration after precipitating for 2 hours, washing with ethanol, dehydrating, and finally drying to obtain aldehyde group CS; S12, dispersing the aldehyde group CS into deionized water, adding catalyst triethylamine, adding PEI aqueous solution dropwise under nitrogen protection, reacting at 60℃, filtering, washing, and drying after the reaction to obtain PEI / CS.

[0007] Further, in step S11, the use amount ratio of the CS and the sodium periodate solution is 3g: 140-160mL.

[0008] Further, in step S12, the use amount ratio of the aldehyde group CS, deionized water, triethylamine, and PEI aqueous solution is 1g: 15mL: 0.1g: 40mL, and the mass fraction of the PEI aqueous solution is 5-10%.

[0009] Further, in step S2, the use amount ratio of the Tween-80, PEI / CS solution, cyclozincetone, DMF, and 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate solution is 0.1mL: 1.2-1.4mL: 0.5g: 4mL: 2.4-4.8mL.

[0010] Further, the PEI / CS solution is composed of PEI / CS and 1% acetic acid aqueous solution, and the use amount ratio of the PEI / CS and the 1% acetic acid aqueous solution is 0.5g: 50mL.

[0011] Further, the 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate solution is composed of 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate and deionized water, and the use amount ratio of the 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate and the deionized water is 0.5g: 50mL.

[0012] In a second aspect, the application provides a cyclozincetone-containing herbicide prepared by the preparation method in any one of the above embodiments.

[0013] The application has the following beneficial effects: 1、The PEI / CS prepared by S1 step has both high positive charge density of polyethyleneimine (PEI) and biocompatibility of chitosan (CS), providing a stable amphiphilic carrier skeleton for subsequent loading; in S2 step, first, the uniform complex of cyclanilide with PEI / CS under the emulsification of Tween-80 is realized in 30 min, and then 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate is quickly introduced in 30 min, and the outer layer protection is formed by the interaction of the negative charge of 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate and the positive charge of PEI / CS, which not only endows the system with ultraviolet resistance by 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate to reduce cyclanilide photolysis, but also efficiently completes the synergistic assembly of 'carrier-pesticide-functional protective agent' through two-step short-time reaction (1 h in total), and the final product has high loading rate, slow-release stability and anti-photodegradation ability, and the preparation efficiency is high and the process is simple and controllable.

[0014] 2、The PEI / CS is obtained by the reaction of PEI and aldehyde-based CS, and an imine bond can be formed in the reaction process, which is a weak reversible covalent bond and can undergo a series of dynamic reversible reactions when stimulated by acid, temperature or water, etc., has self-repairing performance, can repair structural defects and maintain a stable loading network, reduces the leakage of herbicide non-controlled release and regulates the release rate, thereby prolonging the slow-release period; PEI is a polyelectrolyte segment containing a large number of amine groups and ammonium ions, which can make the segment have a large number of positive charges, and electrostatic interaction occurs between the positive charges and the negative charges on the surface of bacteria, which interferes with the normal physiological function of bacteria, increases the permeability of the cell membrane, causes the structure of the cell membrane to be destroyed, and the grafting of the polyethyleneimine segment can improve the antibacterial effect of CS, so that the herbicide can also have antibacterial effect while herbiciding; PEI contains a large number of positive charges, and the modified CS can increase the positive charge content of CS, so that PEI / CS and 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate can be more closely combined, the stability of the carrier is improved, and the slow-release performance of the herbicide can be improved.

[0015] 3、2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate is an ultraviolet absorber, which can reduce cyclanilide photolysis and improve the retention rate of the raw drug; 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate also contains a benzene ring, which can improve the mechanical strength of the carrier and improve the slow-release performance. DETAILED DESCRIPTION

[0016] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application are described in detail below.

[0017] In a first aspect, the present application provides a preparation method of a cyclanilide-containing herbicide, comprising the following steps: S1, preparation of PEI / CS; through cross-linking reaction of aldehyde-based chitosan (CS) and polyethyleneimine (PEI), a composite carrier network with self-repairing performance is formed: the amino group of PEI and the aldehyde group of CS form a dynamic Schiff base bond, which gives the carrier structure a self-repairing ability and reduces pesticide leakage; meanwhile, PEI provides abundant positive charges, which lays a foundation for the closer combination of PEI / CS and 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate.

[0018] S2, mix the emulsifier Tween-80 with the PEI / CS solution, then ultrasonically dissolve the hexazinone dispersed in DMF, then slowly drop the hexazinone solution into the PEI / CS solution under magnetic stirring for 30 min to obtain PEI / CS / hexazinone, then drop the 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate solution into the PEI / CS / hexazinone and stir for 30 min, centrifuge, wash, and dry to obtain the herbicide containing hexazinone.

[0019] PEI / CS has positive charges and can coagulate and complex with 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate with negative charges to form nano-ions. First, the uniform complex of hexazinone and PEI / CS under the emulsification of Tween-80 is realized in 30 min, then 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate is quickly introduced in 30 min to form an outer protective layer through the interaction of its negative charge with the positive charge of PEI / CS, which not only endows the system with ultraviolet resistance and reduces the photolysis of hexazinone through 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate, but also efficiently completes the synergistic assembly of "carrier-pesticide-functional protective agent" through two-step short-time reaction (1 h in total), and the final product has high loading rate, slow-release stability, and anti-photodegradation ability, and the preparation efficiency is high and the process is simple and controllable.

[0020] Further, the specific steps of step S1 are: S11, add CS to a 0.3 mol / L sodium periodate solution, react under nitrogen protection in the dark at 30℃ for 2-3 h, add ethylene glycol solution to terminate the reaction, stand, filter, add acetone to the filtrate, perform suction filtration after precipitating for 2 h, wash with ethanol, then dehydrate, and finally dry to obtain aldehyde-based CS; Sodium periodate selectively oxidizes the hydroxyl group of CS to aldehyde group under nitrogen protection and in the dark, and ethylene glycol terminates the reaction to avoid over-oxidation, and acetone precipitation and ethanol washing can efficiently purify aldehyde-based CS to provide active sites for the subsequent cross-linking reaction with PEI.

[0021] S12, disperse the aldehyde group CS in deionized water, add catalyst triethylamine, nitrogen as protective gas, drop PEI aqueous solution, 60℃ reaction, after the reaction is completed, filter, wash, dry, get PEI / CS.

[0022] In the above steps, the amino group in polyethyleneimine can be Schiff base condensed with aldehyde group in chitosan to form stable covalent crosslinking, triethylamine is both basic catalyst and acid neutralizer in the system, which can significantly improve the imine formation rate and maintain the activity of amine.

[0023] Further, in step S11, the use amount ratio of CS and sodium periodate solution is 3g: 140-160mL. This ratio ensures that sodium periodate moderately oxidizes CS to generate aldehyde groups, avoids insufficient use amount leading to too few aldehyde groups or excessive use amount triggering side reactions, and ensures aldehyde group efficiency.

[0024] Further, in step S12, the use amount ratio of aldehyde group CS, deionized water, triethylamine, PEI aqueous solution is 1g: 15mL: 0.1g: 40mL; the mass fraction of PEI aqueous solution is 5-10%. This ratio and concentration range can promote the crosslinking of aldehyde group CS and PEI to form a structurally stable composite carrier, and balance the reaction efficiency and carrier performance.

[0025] Further, in step S2, the use amount ratio of Tween-80, PEI / CS solution, cyclozinc ketone, DMF, 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate solution is 0.1mL: 1.2-1.4mL: 0.5g: 4mL: 2.4-4.8mL. The use amount of each component is matched, which can realize efficient loading of cyclozinc ketone and uniform compounding of BP-4, and avoid performance fluctuations caused by material waste or imbalance.

[0026] Further, the PEI / CS solution is composed of PEI / CS and 1% acetic acid aqueous solution, and the use amount ratio of PEI / CS and 1% acetic acid aqueous solution is 0.5g: 50mL. The 1% acetic acid aqueous solution can stably disperse PEI / CS, and this ratio ensures that the carrier concentration is appropriate, which is convenient for subsequent reaction with pesticides and functional components.

[0027] Further, the 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate solution is composed of 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate and deionized water, and the use amount ratio of 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate and deionized water is 0.5g: 50mL. This ratio can make BP-4 fully dissolved, ensure uniform dispersion when dropping, and be conducive to stable combination with the carrier and play the role of anti-ultraviolet.

[0028] In a second aspect, the application provides a cyclozinc ketone-containing herbicide prepared by the preparation method of any one of the above.

[0029] The specific embodiments of the present application are described in detail below, but the scope of protection of the present application is not limited by the specific embodiments.

[0030] In the present application, the molecular weight of chitosan is 60KDa, and the degree of deacetylation is 90%.

[0031] Example 1

[0032] The present embodiment provides a preparation method of a herbicide containing cyazofamid, comprising the following steps: S1, preparing PEI / CS; S11, 3g of CS is added into 140mL of 0.3mol / L sodium periodate solution, and the reaction is carried out at 30℃ for 2h under nitrogen protection and in the dark, and the reaction is terminated by adding ethylene glycol solution, and then the solution is left to stand, filtered, and then 2h after the addition of acetone into the filtrate, the solution is subjected to suction filtration, washed with ethanol, and then dehydrated and finally dried to obtain aldehyde-modified CS; S12, 1g of the aldehyde-modified CS is dispersed in 15mL of deionized water, 0.1g of a catalyst triethylamine is added, 40mL of PEI aqueous solution is added dropwise under nitrogen protection, the mass fraction of the PEI aqueous solution is 5%, and the reaction is carried out at 60℃, and after the completion of the reaction, the solution is filtered, washed, and dried to obtain PEI / CS; S2, 0.1mL of an emulsifier Tween-80 is uniformly mixed with 1.2mL of a PEI / CS solution, the PEI / CS solution is composed of PEI / CS and 1% acetic acid aqueous solution, and the dosage ratio of PEI / CS to 1% acetic acid aqueous solution is 0.5g:50mL, 0.5g of cyazofamid is dispersed in 4mL of DMF and ultrasonically dissolved, and then the cyazofamid solution is slowly added into the PEI / CS solution under magnetic stirring to react for 30min to obtain PEI / CS / cyazofamid, and then 2.4mL of a 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate solution is added dropwise into the PEI / CS / cyazofamid solution to react for 30min under stirring, the 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate solution is composed of 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate and deionized water, and the dosage ratio of 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate to deionized water is 0.5g:50mL, and then the solution is centrifuged, washed, and dried to obtain the herbicide containing cyazofamid.

[0033] Example 2

[0034] S1, preparing PEI / CS; S11, 3g CS was added to 0.3mol / L 150mL sodium periodate solution, under nitrogen protection, in the dark, at 30℃ constant temperature reaction 2.5h, add ethylene glycol solution to terminate the reaction, stand, filter, add acetone to the filtrate, precipitate for 2h, then perform suction filtration, then washed with ethanol and dehydrated, finally dried to obtain aldehyde CS; S12, 1g aldehyde CS was dispersed in 15mL deionized water, 0.1g catalyst triethylamine was added, nitrogen was used as protective gas, 40mL PEI aqueous solution was added dropwise, the mass fraction of PEI aqueous solution was 7.5%, and the reaction was carried out at 60℃. After the reaction was completed, PEI / CS was obtained by filtration, washing and drying. S2, 0.1mL emulsifier Tween-80 was mixed with 1.25mL PEI / CS solution, the PEI / CS solution was composed of PEI / CS and 1% acetic acid aqueous solution, and the dosage ratio of PEI / CS to 1% acetic acid aqueous solution was 0.5g:50mL. Then, 0.5g cyclozine was dispersed in 4mL DMF and ultrasonically dissolved, and then the cyclozine solution was slowly added into the PEI / CS solution under magnetic stirring to react for 30min to obtain PEI / CS / cyclozine. Then, 3mL 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate solution was added dropwise into the PEI / CS / cyclozine and stirred for 30min to obtain a herbicide containing cyclozine. The 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate solution was composed of 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate and deionized water, and the dosage ratio of 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate to deionized water was 0.5g:50mL. After centrifugation, washing and drying, the herbicide containing cyclozine was obtained.

[0035] Example 3

[0036] S1, PEI / CS was prepared; S11, 3g CS was added to 0.3mol / L 160mL sodium periodate solution, under nitrogen protection, in the dark, at 30℃ constant temperature reaction 3h, add ethylene glycol solution to terminate the reaction, stand, filter, add acetone to the filtrate, precipitate for 2h, then perform suction filtration, then washed with ethanol and dehydrated, finally dried to obtain aldehyde CS; S12, 1g aldehyde CS was dispersed in 15mL deionized water, 0.1g catalyst triethylamine was added, nitrogen was used as protective gas, 40mL PEI aqueous solution was added dropwise, the mass fraction of PEI aqueous solution was 10%, and the reaction was carried out at 60℃. After the reaction was completed, PEI / CS was obtained by filtration, washing and drying. S2, 0.1 mL emulsifier Tween-80 was mixed with 1.3 mL PEI / CS solution, the PEI / CS solution was composed of PEI / CS and 1% acetic acid aqueous solution, the dosage ratio of PEI / CS and 1% acetic acid aqueous solution was 0.5 g: 50 mL, then 0.5 g of hexazinone was dispersed in 4 mL DMF and ultrasonically dissolved, then the hexazinone solution was slowly added into the PEI / CS solution under magnetic stirring for reaction for 30 min to obtain PEI / CS / hexazinone, and then 3.6 mL of 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate solution was added dropwise into the PEI / CS / hexazinone and stirred for reaction for 30 min, the 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate solution was composed of 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate and deionized water, the dosage ratio of 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate and deionized water was 0.5 g: 50 mL, centrifugation, washing, and drying to obtain the hexazinone-containing herbicide.

[0037] Example 4

[0038] S1, PEI / CS was prepared; S11, 3 g of CS was added into 0.3 mol / L 140 mL sodium periodate solution, under nitrogen protection, in dark, constant temperature reaction at 30℃ for 2 h, ethylene glycol solution was added to terminate the reaction, standing, filtration, adding acetone in the filtrate, precipitating for 2 h, then suction filtration, washing with ethanol, and then dehydration, finally drying to obtain aldehyde group CS; S12, 1 g of aldehyde group CS was dispersed in 15 mL deionized water, 0.1 g of catalyst triethylamine was added, nitrogen was used as protective gas, 40 mL of PEI aqueous solution was added dropwise, the mass fraction of PEI aqueous solution was 5%, 60℃ reaction, after the reaction was completed, filtration, washing, and drying to obtain PEI / CS; S2, 0.1 mL emulsifier Tween-80 was mixed with 1.3 mL PEI / CS solution, the PEI / CS solution was composed of PEI / CS and 1% acetic acid aqueous solution, the dosage ratio of PEI / CS and 1% acetic acid aqueous solution was 0.5 g: 50 mL, then 0.5 g of hexazinone was dispersed in 4 mL DMF and ultrasonically dissolved, then the hexazinone solution was slowly added into the PEI / CS solution under magnetic stirring for reaction for 30 min to obtain PEI / CS / hexazinone, and then 3.6 mL of 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate solution was added dropwise into the PEI / CS / hexazinone and stirred for reaction for 30 min, the 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate solution was composed of 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate and deionized water, the dosage ratio of 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate and deionized water was 0.5 g: 50 mL, centrifugation, washing, and drying to obtain the hexazinone-containing herbicide.

[0039] Example 5

[0040] S1. Preparation of PEI / CS; S11. Add 3g of CS to 140mL of 0.3mol / L sodium periodate solution. Under nitrogen protection and in the dark, react at 30℃ for 2h. Add ethylene glycol solution to terminate the reaction, let stand, filter, add acetone to the filtrate, precipitate for 2h, filter under vacuum, wash with ethanol and dehydrate, and finally dry to obtain aldehyde-modified CS. S12. Disperse 1g of aldehyde-modified CS in 15mL of deionized water, add 0.1g of triethylamine catalyst, use nitrogen as a protective gas, add 40mL of PEI aqueous solution (mass fraction of 5%), react at 60℃, and after the reaction is complete, filter, wash and dry to obtain PEI / CS. S2. Mix 0.1 mL of emulsifier Tween-80 with 1.4 mL of PEI / CS solution. The PEI / CS solution consists of PEI / CS and a 1% acetic acid aqueous solution, with a volume ratio of 0.5 g: 50 mL. Then, disperse 0.5 g of cycloazinone in 4 mL of DMF and dissolve it by sonication. Then, under magnetic stirring, slowly add the cycloazinone solution dropwise to the PEI / CS solution and react for 30 min to obtain PEI / CS / cycloazinone. Then, add 4.8 mL of... A sodium 2-hydroxy-4-methoxybenzophenone-5-sulfonate solution was added dropwise to PEI / CS / cycloazinone and stirred for 30 min. The sodium 2-hydroxy-4-methoxybenzophenone-5-sulfonate solution consisted of sodium 2-hydroxy-4-methoxybenzophenone-5-sulfonate and deionized water. The ratio of sodium 2-hydroxy-4-methoxybenzophenone-5-sulfonate to deionized water was 0.5 g: 50 mL. After centrifugation, washing, and drying, a herbicide containing cycloazinone was obtained.

[0041] Comparative Example 1

[0042] The only difference between this comparative example and Example 1 is that an equal amount of sodium benzenesulfonate is used to replace sodium 2-hydroxy-4-methoxybenzophenone-5-sulfonate.

[0043] Comparative Example 2

[0044] The only difference between this comparative example and Example 1 is that "PEI / CS" is replaced with an equal amount of "CS".

[0045] Comparative Example 3

[0046] The only difference between this comparative example and Example 1 is that "sodium benzenesulfonate" is replaced with an equal amount of "sodium 2-hydroxy-4-methoxybenzophenone-5-sulfonate", and "PEI / CS" is replaced with an equal amount of "CS".

[0047] The herbicides prepared in Examples 1 to 5 and Comparative Examples 1 to 3 were subjected to performance tests, and the results are shown in Table 1. I. Sustained-release performance test: 5 mg of the sample obtained from the examples and comparative examples was dissolved in 5 mL of release medium (DMF:water = 6:4), then 95 mL of release medium was added. The mixture was stirred at 100 rpm in the dark at 25°C. At regular intervals, 3 mL of release medium was taken, and the same volume of blank medium was added. The concentration of cycloazinone was determined using a UV spectrophotometer. The cumulative release rate was calculated using the following formula.

[0048]

[0049] Where: Ep is the cumulative release amount, %; Ve is the volume of the release medium taken out (L); Ci is the mass concentration of cycloazinone in the release medium at the i-th sampling, mg / L; V0 is the total volume of the release medium (L); Cn is the mass concentration of cycloazinone in the release medium at the n-th sampling, mg / L; mp is the total mass of the sample (mg). The test results are shown in Table 1: Table 1

[0050] As shown in Table 1, the sustained-release performance of the herbicides in Examples 1-5 is higher than that in Comparative Examples 1-3. Comparative Example 2, which replaced "PEI / CS" with an equal amount of "CS", showed lower sustained-release performance than Example 1. This indicates that PEI contains a large amount of positive charge. Modifying CS can increase the positive charge content of CS, allowing PEI / CS to bind more tightly with sodium 2-hydroxy-4-methoxybenzophenone-5-sulfonate, thus improving the stability of the carrier and enhancing the sustained-release performance of the herbicide. Furthermore, the reaction of PEI with aldehyde-modified CS to obtain PEI / CS can form imine bonds during the reaction. Imine bonds are weakly reversible covalent bonds that can undergo a series of dynamic reversible reactions under stimulation from acids, temperatures, or water, exhibiting self-repairing properties. These dynamic bonds can repair structural defects, maintain a stable loading network, reduce uncontrolled release leakage of the herbicide, and regulate the release rate, thereby extending the sustained-release period.

[0051] (2) Resistance to UV photolysis: Herbicide dispersions of the same concentration were prepared in Examples 1 to 5 and Comparative Examples 1 to 3. The solutions were placed under UV lamps (36W, 254nm) for irradiation. Samples were taken at intervals and the concentrations were calculated by high performance liquid chromatography.

[0052] Table 2

[0053] As can be seen from Table 2, the herbicides of Examples 1 to 5 have better UV resistance than those of Comparative Examples 1 to 3.

[0054] (3) Antibacterial properties: The filter paper method was used: the herbicides prepared in Examples 1 to 5 and Comparative Examples 1 to 3 were placed in petri dishes containing bacterial strains and incubated at 25°C in a constant temperature incubator. After 7 days, the growth was observed and the size of the inhibition zone was measured (the bacterial strain grows to form multiple colonies, and each colony has a transparent zone around it where no colonies grow, which is the inhibition zone) to compare the toxicity of the fungicides. The bacterial strain used was Staphylococcus aureus, and the test results are shown in Table 3.

[0055] Table 3

[0056] As can be seen from Table 3, the antibacterial properties of the herbicides in Examples 1 to 5 are better than those in Comparative Examples 1 to 3.

[0057] The above-disclosed embodiments are merely a few specific examples of the present invention. However, the embodiments of the present invention are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A process for the preparation of a herbicide comprising cyprosulfamide, characterized in that, The method comprises the following steps: S1, preparing PEI / CS; S2, mixing Tween-80 with the PEI / CS solution, ultrasonically dissolving cycloxaprid in DMF, then slowly adding the cycloxaprid solution into the PEI / CS solution under magnetic stirring for 30 min to obtain PEI / CS / cycloxaprid, then adding 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate solution into the PEI / CS / cycloxaprid for stirring reaction for 30 min, centrifuging, washing, drying to obtain the cycloxaprid-containing herbicide.

2. The method of preparing a herbicide containing hexazinone according to claim 1, characterized by, The specific steps of the step S1 are: S11, adding CS into 0.3 mol / L sodium periodate solution, reacting at 30℃ for 2-3 h under nitrogen protection and in dark, adding ethylene glycol solution to terminate the reaction, standing, filtering, adding acetone into the filtrate, performing suction filtration after precipitating for 2 h, washing with ethanol, dehydrating, and finally drying to obtain aldehyde-modified CS; S12, dispersing the aldehyde-modified CS in deionized water, adding triethylamine, adding PEI aqueous solution dropwise under nitrogen protection, and reacting at 60℃, after the reaction is completed, filtering, washing, and drying to obtain PEI / CS.

3. The method of claim 2, wherein the cyclozifurone-containing herbicide is prepared by the steps of: In the step S11, the use amount ratio of the CS to the sodium periodate solution is 3g:140-160 mL.

4. The method of claim 2, wherein the cyclozifrone-containing herbicide is prepared by the steps of: In the step S12, the use amount ratio of the aldehyde-modified CS, deionized water, triethylamine, and PEI aqueous solution is 1g:15 mL:0.1g:40 mL.

5. The method of claim 2, wherein the cyclozifurone-containing herbicide is prepared by the steps of: In the step S12, the mass fraction of the PEI aqueous solution is 5-10%.

6. The method of claim 1, wherein the cyclozifrone-containing herbicide is prepared by the steps of: In the step S2, the use amount ratio of the Tween-80, PEI / CS solution, cycloxaprid, DMF, and 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate solution is 0.1 mL:1.2-1.4 mL:0.5g:4 mL:2.4-4.8 mL.

7. The method of claim 1, wherein the cyclozifrone-containing herbicide is prepared by the steps of: The PEI / CS solution is composed of PEI / CS and 1% acetic acid aqueous solution, and the use amount ratio of the PEI / CS to the 1% acetic acid aqueous solution is 0.5g:50 mL.

8. The method of claim 1, wherein the cyclozifrone-containing herbicide is prepared by the steps of: The 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate solution is composed of 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate and deionized water.

9. The method of claim 8, wherein the cyclozifrone-containing herbicide is prepared by the steps of: The use amount ratio of the 2-hydroxy-4-methoxybenzophenone-5-sodium sulfonate to the deionized water is 0.5g:50 mL.

10. A herbicide comprising cyprosulfamide, characterized in that, The herbicide is prepared by the method in any one of claims 1-9.

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