A kind of polymethacrylate guanidine salt and its preparation method and application

Abstract

The present invention discloses a polymethacrylate guanidine salt and a preparation method and application thereof. The polymethacrylate guanidine salt of the present invention comprises the following polymer segment: #imgabs0# wherein R is a C1-C5 alkyl group or a benzyl group, x and y are both integers, 1400≤x+y≤2700, and the ratio of x to y is 1:0-1. The polymethacrylate guanidine salt of the present invention has a good inhibitory and killing effect on Foc4, and can maintain bactericidal activity in the soil for a long time, and its preparation process is simple, and is suitable for large-scale promotion and application.

Description

Technical Field

[0001] The invention relates to the technical field of bactericidal materials, and in particular to a polymethacrylate guanidine salt and a preparation method and application thereof. Background Art

[0002] Banana wilt is a soil-borne disease caused by the fungus Fusarium oxysporum f.sp.cubense (Foc) infecting the vascular bundle of banana plants. Foc mainly has physiological race 1 and physiological race 4, among which physiological race 4 (Fusarium oxysporum f.sp.cubense tropical race 4, FocTR4) has the widest range of pathogenicity and can cause diseases in almost all main banana varieties. Foc is a saprophytic fungus that reproduces by asexual reproduction. During its life cycle, it can produce spores in different forms and disperse and survive in the soil environment for a long time. Once it has the opportunity, it will infect bananas from the roots, and there is no effective way to prevent bananas from dying after infection. Therefore, it is particularly important to seek a method that can effectively inhibit banana wilt pathogens while they are still in the spore stage.

[0003] At present, there are two main methods for the prevention and control of banana wilt: 1) Chemical control: The most commonly used and effective ones are benzimidazole agents such as baozhida, carbendazim, pentachloronitrobenzene, and methyl thiophanate (in the process of agent screening, it was found that the best control effect on banana wilt pathogen was prochloraz, but it was only limited to laboratory use and was not suitable for practical application). However, since these small molecule chemical reagents are not easily adsorbed in the soil, they will be washed into the ecosystem with rainwater, eventually causing environmental pollution; 2) Biological control: Pseudomonas fluorescens has a strong inhibitory effect on banana wilt, and can activate the systemic acquired resistance of the host banana, which can improve the disease resistance of bananas. In addition, fungi such as Trichoderma harzianum and non-pathogenic Fusarium oxysporum also have significant antibacterial effects in the prevention and control of banana wilt, but these studies are limited to greenhouse experimental environments. Due to the extremely complex diversity of field microorganisms and the rapid evolution of banana wilt pathogens with changes in the environment, the effect of biological control in the field is not ideal.

[0004] Therefore, it is of great significance to develop a fungicide that has a good inhibitory effect on Foc4 and can maintain fungicidal activity in the soil for a long time. Summary of the invention

[0005] The purpose of the present invention is to provide a polymethacrylate guanidine salt and a preparation method and application thereof.

[0006] The technical solution adopted by the present invention is:

[0007] A polymethacrylate guanidine salt comprising the following polymer segments:

[0008] In the formula, R is a C1-C5 alkyl group or a benzyl group, x and y are both integers, 1400≤x+y≤2700, and the ratio of x to y is 1:0-1.

[0009] Preferably, R is one of methyl, tert-butyl and benzyl.

[0010] Preferably, the ratio of x to y is 1:0.11-0.5.

[0011] More preferably, the ratio of x to y is 1:0.3-0.5.

[0012] Preferably, the polymethacrylate guanidine salt comprises the following polymer segments:

[0013] In the formula, z is an integer ranging from 10 to 40.

[0014] A method for preparing the polymethacrylate guanidine salt as described above comprises the following steps:

[0015] 1) dispersing 2-aminoethyl methacrylate hydrochloride, methacrylate and an initiator in an organic solvent, and then reacting in a protective atmosphere to obtain an intermediate product;

[0016] Alternatively, 2-aminoethyl methacrylate hydrochloride, methacrylate, and an initiator are dispersed in an organic solvent, and then reacted in a protective atmosphere to obtain an intermediate product;

[0017] 2) The intermediate product obtained in step 1), trimethylamine and pyrazole-1-carboxamidine monohydrochloride are dispersed in water, and then reacted in a protective atmosphere to obtain polymethacrylate guanidine salt.

[0018] Preferably, in step 1), the molar ratio of 2-aminoethyl methacrylate hydrochloride (AMA) to methacrylate is 1:0-1.

[0019] Further preferably, in step 1), the molar ratio of 2-aminoethyl methacrylate hydrochloride to methacrylate is 1:0.11-0.5.

[0020] More preferably, in step 1), the molar ratio of 2-aminoethyl methacrylate hydrochloride to methacrylate is 1:0.3-0.5.

[0021] Preferably, step 1) The amount used is 0.5% to 1.5% of the total mass of 2-aminoethyl methacrylate hydrochloride and methacrylate. It is a monomer containing a fluorescent group and has a fluorescent labeling effect. It can be used to detect the adsorption and migration behavior of polymethacrylate guanidine salt in soil.

[0022] Preferably, the methacrylate in step 1) is at least one of methyl methacrylate (MMA), tert-butyl methacrylate (tBMA), and benzyl methacrylate (BMA).

[0023] Preferably, the initiator in step 1) is an oil-soluble azo initiator.

[0024] Further preferably, the initiator in step 1) is at least one of azobisisobutyronitrile (AIBN) and azobisisoheptanenitrile (ABVN).

[0025] Preferably, the amount of the initiator in step 1) is 0.5% to 2.5% of the total mass of 2-aminoethyl methacrylate hydrochloride and methacrylate.

[0026] Further preferably, the amount of the initiator used in step 1) is 1.5% to 2% of the total mass of 2-aminoethyl methacrylate hydrochloride and methacrylate.

[0027] Preferably, the organic solvent in step 1) is at least one of dimethyl sulfoxide (DMSO) and methanol.

[0028] Preferably, the amount of the organic solvent in step 1) is 5 to 20 times the total mass of 2-aminoethyl methacrylate hydrochloride and methacrylate.

[0029] Further preferably, the amount of the organic solvent used in step 1) is 10 to 15 times the total mass of 2-aminoethyl methacrylate hydrochloride and methacrylate.

[0030] Preferably, the protective atmosphere in step 1) is a nitrogen atmosphere or a rare gas atmosphere.

[0031] Preferably, the reaction in step 1) is carried out at 55°C to 70°C, and the reaction time is 10h to 20h.

[0032] Further preferably, the reaction in step 1) is carried out at 60°C to 70°C, and the reaction time is 12h to 18h.

[0033] Preferably, step 1) further separates and purifies the intermediate product, and the specific operation of separation and purification is as follows: precipitate the intermediate product with acetone, then redissolve it with dimethyl sulfoxide, precipitate the intermediate product with acetone again, repeat the dissolution and precipitation 2 to 5 times, filter, and then place in a vacuum oven at 40°C to 55°C for drying.

[0034] Preferably, the molar ratio of the intermediate product, trimethylamine and pyrazole-1-carboxamidine monohydrochloride in step 2) is 1:1-3:3-8.

[0035] Further preferably, in step 2), the molar ratio of the intermediate product, trimethylamine and pyrazole-1-carboxamidine monohydrochloride is 1:1.5:3.

[0036] Preferably, the protective atmosphere in step 2) is a nitrogen atmosphere or a rare gas atmosphere.

[0037] Preferably, the reaction in step 2) is carried out at 25°C to 40°C, and the reaction time is 20h to 30h.

[0038] Further preferably, the reaction in step 2) is carried out at 25°C to 35°C, and the reaction time is 22h to 26h.

[0039] Preferably, step 2) further separates and purifies the polymethacrylate guanidine salt, and the specific operation of separation and purification is as follows: the polymethacrylate guanidine salt is placed in a dialysis bag with a molecular weight cutoff of 1000 for dialysis, then subjected to reduced pressure distillation and freeze drying, then redissolved in water, and then freeze dried, and the dissolution and freeze drying are repeated 3 to 5 times.

[0040] The synthesis reaction of the polymethacrylate guanidine salt in the present invention is shown in formula (I) or formula (II):

[0041] Formula (I):

[0042] Formula (II):

[0043] Application of the polymethacrylate guanidine salt as described above in preventing and treating banana wilt.

[0044] An antibacterial agent comprises the polymethacrylate guanidine salt.

[0045] The beneficial effects of the present invention are as follows: the polymethacrylate guanidine salt of the present invention has a good inhibitory and killing effect on Foc4 and can maintain bactericidal activity in the soil for a long time, and the preparation process thereof is simple and suitable for large-scale promotion and application.

[0046] Specifically:

[0047] 1) The polymethacrylate guanidine salt of the present invention has excellent antibacterial properties, has a strong inhibitory effect on the growth of spores and hyphae of Foc4, can be stably adsorbed in the soil after being applied to the soil, is not easy to be lost, and can maintain a strong antibacterial activity for a long time, and finally can achieve good prevention and control and long-term inhibition of banana wilt;

[0048] 2) The preparation process of the polymethacrylate guanidine salt of the present invention is simple, and the final product can be obtained by free radical polymerization and guanidinization conversion. The guanidine content can be controlled by controlling the feed ratio, and the post-treatment of the product is simple, which is suitable for large-scale industrial production and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 The infrared spectra of the intermediate products and polymethacrylate guanidine salt in Examples 1 to 4 are shown.

[0050] Figure 2 The hydrogen nuclear magnetic resonance spectra of the intermediate products in Examples 1 to 4 are shown in FIG.

[0051] Figure 3 The hydrogen nuclear magnetic resonance spectra of the polymethacrylate guanidine salts of Examples 1 to 4 are shown.

[0052] Figure 4 The antibacterial effect diagram of the polymethacrylate guanidine salt of Examples 1 to 4.

[0053] Figure 5 The graph is a test result of the adsorption characteristics of polymethacrylate guanidine salts of Examples 5 to 8 in soil. DETAILED DESCRIPTION

[0054] The present invention will be further explained and illustrated below in conjunction with specific embodiments.

[0055] Embodiment 1:

[0056] A polymethacrylate guanidine salt, the preparation method of which comprises the following steps:

[0057] 1) 2.38 g of 2-aminoethyl methacrylate hydrochloride was stirred and dissolved in 10 mL of dimethyl sulfoxide, and then heated and stirred to 70° C. under nitrogen protection, and then 0.0472 g of azobisisobutyronitrile was dissolved in 3 mL of dimethyl sulfoxide and slowly added dropwise to the reaction system. After the addition, the mixture was stirred at 70° C. for 15 h, and then the reaction product was poured into acetone for precipitation and filtered. The filtered solid was redissolved in dimethyl sulfoxide, and then precipitated with acetone, filtered, and the precipitation and filtration were repeated 3 times. The filtered solid was then placed in a vacuum oven at 50° C. and dried to obtain an intermediate product (white solid, denoted as PA);

[0058] 2) 2.2 g of the intermediate product obtained in step 1), 8.3 g of a 30% trimethylamine solution and 3.1 g of pyrazole-1-carboximidamide monohydrochloride were dispersed in 60 mL of deionized water, and then stirred at room temperature (25° C.) for 24 h under nitrogen protection. The reaction product was then placed in a dialysis bag with a molecular weight cutoff of 1000 and dialyzed for two days, followed by reduced pressure distillation and freeze-drying to obtain polymethacrylate guanidine salt (denoted as PG).

[0059] Embodiment 2:

[0060] A polymethacrylate guanidine salt, the preparation method of which comprises the following steps:

[0061] 1) 2.47 g of 2-aminoethyl methacrylate hydrochloride and 0.64 g of methyl methacrylate were stirred and dissolved in 20 mL of dimethyl sulfoxide, and then heated and stirred to 70° C. under nitrogen protection, and then 0.0699 g of azobisisobutyronitrile was dissolved in 3 mL of dimethyl sulfoxide and slowly added dropwise to the reaction system. After the addition, the mixture was stirred at 70° C. for 15 h, and then the reaction product was poured into acetone for precipitation and filtered. The filtered solid was redissolved in dimethyl sulfoxide, and then precipitated with acetone, filtered, and the precipitation and filtration were repeated 3 times. The filtered solid was then placed in a vacuum oven at 50° C. and dried to obtain an intermediate product (white solid, denoted as PA-MMA);

[0062] 2) 2.5 g of the intermediate product obtained in step 1), 8.8 g of a 30% mass fraction trimethylamine solution and 3.25 g of pyrazole-1-carboximidamide monohydrochloride were dispersed in 60 mL of deionized water, and then stirred at room temperature for 24 h under nitrogen protection. The reaction product was then placed in a dialysis bag with a molecular weight cutoff of 1000 and dialyzed for two days, and then subjected to reduced pressure distillation and freeze-drying to obtain polymethacrylate guanidine salt (denoted as PG-MMA).

[0063] Embodiment 3:

[0064] A polymethacrylate guanidine salt, the preparation method of which comprises the following steps:

[0065] 1) 2.47 g of 2-aminoethyl methacrylate hydrochloride and 0.91 g of tert-butyl methacrylate were stirred and dissolved in 20 mL of dimethyl sulfoxide, and then heated and stirred to 70° C. under nitrogen protection, and then 0.0699 g of azobisisobutyronitrile was dissolved in 3 mL of dimethyl sulfoxide and slowly added dropwise to the reaction system. After the addition, the mixture was stirred at 70° C. for 15 h, and then the reaction product was poured into acetone for precipitation and filtered. The filtered solid was redissolved in dimethyl sulfoxide, and then precipitated with acetone, filtered, and the precipitation and filtration were repeated 3 times. The filtered solid was then placed in a vacuum oven at 50° C. and dried to obtain an intermediate product (white solid, denoted as PA-tBMA);

[0066] 2) 2.5 g of the intermediate product obtained in step 1), 8.8 g of a 30% trimethylamine solution and 3.25 g of pyrazole-1-carboximidamide monohydrochloride were dispersed in 60 mL of deionized water, and then stirred at room temperature for 24 h under nitrogen protection. The reaction product was then placed in a dialysis bag with a molecular weight cutoff of 1000 and dialyzed for two days, followed by reduced pressure distillation and freeze-drying to obtain polymethacrylate guanidine salt (denoted as PG-tBMA).

[0067] Embodiment 4:

[0068] A polymethacrylate guanidine salt, the preparation method of which comprises the following steps:

[0069] 1) 2.47 g of 2-aminoethyl methacrylate hydrochloride and 1.13 g of benzyl methacrylate were stirred and dissolved in 20 mL of dimethyl sulfoxide, and then heated and stirred to 70° C. under nitrogen protection, and then 0.0699 g of azobisisobutyronitrile was dissolved in 3 mL of dimethyl sulfoxide and slowly added dropwise to the reaction system. After the addition, the mixture was stirred at 70° C. for 15 h, and then the reaction product was poured into acetone for precipitation and filtered. The filtered solid was redissolved in dimethyl sulfoxide, and then precipitated with acetone, filtered, and the precipitation and filtration were repeated 3 times. The filtered solid was then placed in a vacuum oven at 50° C. and dried to obtain an intermediate product (white solid, denoted as PA-BMA);

[0070] 2) Disperse 2.5 g of the intermediate product obtained in step 1), 8.8 g of a 30% trimethylamine solution and 3.25 g of pyrazole-1-carboximidamide monohydrochloride in 60 mL of deionized water, and stir at room temperature for 24 h under nitrogen protection. Then, put the reaction product into a dialysis bag with a molecular weight cutoff of 1000 and dialyze for two days, and then perform reduced pressure distillation and freeze-drying to obtain polymethacrylate guanidine salt (denoted as PG-BMA).

[0071] Embodiment 5:

[0072] A polymethacrylate guanidine salt, the preparation method of which comprises the following steps:

[0073] 1) 1.1 g of 2-aminoethyl methacrylate hydrochloride, 0.166 g of methyl methacrylate and 0.0341 g of The mixture was dissolved in 10 mL of dimethyl sulfoxide with stirring, and then heated to 70°C under nitrogen protection with stirring. 0.0273 g of azobisisobutyronitrile was dissolved in 3 mL of dimethyl sulfoxide and then slowly added dropwise to the reaction system. After the addition, the mixture was stirred at 70°C for 15 h. The reaction product was poured into acetone for precipitation and filtered. The filtered solid was redissolved in dimethyl sulfoxide, precipitated with acetone, filtered, and the precipitation and filtration were repeated 3 times. The filtered solid was dried in a vacuum oven at 50°C to obtain an intermediate product (white solid, denoted as PA-MMA-FL).

[0074] 2) Disperse 1 g of the intermediate product obtained in step 1), 3.9 g of a 30% trimethylamine solution and 1.4 g of pyrazole-1-carboximidamide monohydrochloride in 50 mL of deionized water, and stir at room temperature for 24 h under nitrogen protection. Then, put the reaction product into a dialysis bag with a molecular weight cutoff of 1000 and dialyze for two days, and then perform reduced pressure distillation and freeze-drying to obtain polymethacrylate guanidine salt (denoted as PG-MMA-FL).

[0075] Embodiment 6:

[0076] A polymethacrylate guanidine salt, the preparation method of which comprises the following steps:

[0077] 1) 1.1 g of 2-aminoethyl methacrylate hydrochloride, 0.244 g of tert-butyl methacrylate and 0.0341 g of The mixture was dissolved in 10 mL of dimethyl sulfoxide with stirring, and then heated to 70°C under nitrogen protection with stirring. 0.0273 g of azobisisobutyronitrile was dissolved in 3 mL of dimethyl sulfoxide and then slowly added dropwise to the reaction system. After the addition, the mixture was stirred at 70°C for 15 h. The reaction product was poured into acetone for precipitation and filtered. The filtered solid was redissolved in dimethyl sulfoxide, precipitated with acetone, filtered, and the precipitation and filtration were repeated 3 times. The filtered solid was then dried in a vacuum oven at 50°C to obtain an intermediate product (white solid, denoted as PA-tBMA-FL).

[0078] 2) Disperse 1 g of the intermediate product obtained in step 1), 3.9 g of a 30% trimethylamine solution and 1.4 g of pyrazole-1-carboximidamide monohydrochloride in 50 mL of deionized water, and stir at room temperature for 24 h under nitrogen protection. Then, put the reaction product into a dialysis bag with a molecular weight cutoff of 1000 and dialyze for two days, and then perform reduced pressure distillation and freeze-drying to obtain polymethacrylate guanidine salt (denoted as PG-tBMA-FL).

[0079] Embodiment 7:

[0080] A polymethacrylate guanidine salt, the preparation method of which comprises the following steps:

[0081] 1) 1.1 g of 2-aminoethyl methacrylate hydrochloride, 0.295 g of benzyl methacrylate and 0.0341 g of The mixture was dissolved in 10 mL of dimethyl sulfoxide with stirring, and then heated to 70°C under nitrogen protection with stirring. 0.0273 g of azobisisobutyronitrile was dissolved in 3 mL of dimethyl sulfoxide and then slowly added dropwise to the reaction system. After the addition, the mixture was stirred at 70°C for 15 h. The reaction product was poured into acetone for precipitation and filtered. The filtered solid was redissolved in dimethyl sulfoxide, precipitated with acetone, filtered, and the precipitation and filtration were repeated 3 times. The filtered solid was dried in a vacuum oven at 50°C to obtain an intermediate product (white solid, denoted as PA-BMA-FL).

[0082] 2) Disperse 1 g of the intermediate product obtained in step 1), 3.9 g of a 30% trimethylamine solution and 1.4 g of pyrazole-1-carboximidamide monohydrochloride in 50 mL of deionized water, and stir at room temperature for 24 h under nitrogen protection. Then, put the reaction product into a dialysis bag with a molecular weight cutoff of 1000 and dialyze for two days, and then perform reduced pressure distillation and freeze-drying to obtain polymethacrylate guanidine salt (denoted as PG-BMA-FL).

[0083] Embodiment 8:

[0084] A polymethacrylate guanidine salt, the preparation method of which comprises the following steps:

[0085] 1) 1.1 g of 2-aminoethyl methacrylate hydrochloride and 0.0251 g of The mixture was dissolved in 10 mL of dimethyl sulfoxide with stirring, and then heated to 70°C under nitrogen protection with stirring. 0.0218 g of azobisisobutyronitrile was dissolved in 3 mL of dimethyl sulfoxide and then slowly added dropwise to the reaction system. After the addition, the mixture was stirred at 70°C for 15 h. The reaction product was poured into acetone for precipitation and filtered. The filtered solid was redissolved in dimethyl sulfoxide, precipitated with acetone, filtered, and the precipitation and filtration were repeated 3 times. The filtered solid was dried in a vacuum oven at 50°C to obtain an intermediate product (white solid, denoted as PA-FL).

[0086] 2) Disperse 1 g of the intermediate product obtained in step 1), 3.9 g of a 30% trimethylamine solution and 1.4 g of pyrazole-1-carboximidamide monohydrochloride in 50 mL of deionized water, and stir at room temperature for 24 h under nitrogen protection. Then, put the reaction product into a dialysis bag with a molecular weight cutoff of 1000 and dialyze for two days, and then perform reduced pressure distillation and freeze-drying to obtain polymethacrylate guanidine salt (denoted as PG-FL).

[0087] Performance Testing:

[0088] 1) The infrared spectra of the intermediate products and polymethacrylate guanidine salts in Examples 1 to 4 are as follows Figure 1 As shown, the nuclear magnetic resonance hydrogen spectra of the intermediate products in Examples 1 to 4 are as follows Figure 2 As shown (the intermediate products PA, PA-MMA, PA-tBMA and PA-BMA were placed in deuterated water for measurement), the nuclear magnetic resonance hydrogen spectra of the polymethacrylate guanidine salts in Examples 1 to 4 are as follows Figure 3 As shown (PG, PG-MMA, PG-tBMA and PG-BMA were measured in deuterated water).

[0089] Depend on Figure 1 It can be seen that the intermediate products and polymethacrylate guanidine salts in Examples 1 to 4 all have a 1730 cm -1 The C=O peak at 1146 cm -1 After guanidinization, the CO peak at 1624 cm -1 The C=N peak at , indicating that the amine group was successfully converted into a guanidine group.

[0090] Depend on Figure 2 and Figure 3 It can be seen that after the intermediate products in Examples 1 to 4 are converted into polymethacrylate guanidine salts, the chemical shift of the methylene hydrogen near the amine group changes, indicating that the amine group is successfully converted into the guanidine group.

[0091] 2) Antibacterial effect test (Fusarium oxysporum f.sp.cubense (EFSmith) Snyder & Hansen, race 4 (Foc4) provided by Fungal Laboratory, Department of Plant Pathology, College of Plant Protection, South China Agricultural University):

[0092] Using dodecyl dimethyl benzyl ammonium chloride (benzalkonium chloride, denoted as BC) as a reference, Escherichia coli (E. coli) as a representative of Gram-negative bacteria, Staphylococcus albus (S. albus) as a representative of Gram-positive bacteria, Candida albicans (C. albicans) as a representative of pathogenic fungi, and Fusarium oxysporum Cuban specialization type 4 physiological subspecies (Foc4) as a representative of plant pathogenic fungi, the inhibitory effects of the polymethacrylate guanidine salts of Examples 1 to 4 on the above four bacteria / fungi were tested, and the antibacterial experiment was as follows:

[0093] The cultured bacteria or fungi were suspended and diluted to 10 using a hemocytometer. 5CFU / mL concentration, then 100 μL of bacterial or fungal suspension and 100 μL of different concentrations of polymethacrylate guanidine salt solution of Examples 1 to 4 were mixed and transferred to a 96-well plate, the control group used culture medium instead of polymethacrylate guanidine salt, each treatment was repeated 3 times, the 96-well plate was cultured at 28°C (fungus) or 37°C (bacteria) for 2 days, and then 50 μL of 0.5% mass fraction of 2,3,5-triphenyltetrazolium chloride (TTC) solution was added to each well, and then cultured in the dark for 2 hours, the minimum inhibitory concentration (MIC) value is the lowest concentration without visible bacterial or fungal growth, that is, the lowest concentration that is not dyed red by TTC, and then 100 μL of the mixture in the 96-well plate at or above the MIC value was transferred to a blank culture medium for 48 hours, the minimum fungicidal concentration (MFC) or minimum bactericidal concentration (MBC) value is the lowest concentration at which less than 5 colonies are observed to form, and the test results are as follows Figure 4 shown.

[0094] Depend on Figure 4 It can be seen that the polymethacrylate guanidine salts (PG, PG-MMA, PG-tBMA and PG-BMA) of Examples 1 to 4 have good inhibitory effects on Escherichia coli (E. coli), Staphylococcus albus (S. albus), Candida albicans (C. albicans) and Foc4. Among them, when R is methyl, the antibacterial effect is the best, and the minimum inhibitory concentration for Foc4 is equivalent to that of benzalkonium chloride (BC), indicating that PG-MMA has a good inhibitory effect on Foc4.

[0095] 3) Soil adsorption performance test:

[0096] The polymethacrylate guanidine salts of Examples 5 to 8 were treated with 0.01 mol / L CaCl 2 The solutions were respectively prepared into solutions with a concentration of 400 mg / L of polymethacrylate guanidine salt, 100 mL of each solution was taken into a 250 mL conical flask, and 1 g of sterilized soil was added. The solution was sealed with a rubber stopper and placed in a constant temperature shaking incubator at 28 °C and 120 r / min. The solution was then placed in a constant temperature shaking incubator. The starting time was recorded as 0. 1 mL of the upper turbid solution was taken at 2 min, 3 min, 5 min, 10 min, 15 min, 20 min, 30 min, 40 min, 60 min, 80 min, 100 min, 120 min, 150 min, 300 min, 600 min and 1200 min, and 1 mL of 0.01 mol / L CaCl was added at the same time. 2The solution was centrifuged at 3000 r / min for 5 min, and the absorbance of the supernatant was measured by a fluorescence spectrophotometer. The adsorption characteristics of the polymethacrylate guanidine salts of Examples 5 to 8 in the soil were fitted according to the formula. The test results are shown in FIG. Figure 5 shown.

[0097] Depend on Figure 5 It can be seen that the polymethacrylate guanidine salts (PG-MMA-FL, PG-tBMA-FL, PG-BMA-FL and PG-FL) of Examples 5 to 8 are easily adsorbed in the soil, and the saturated adsorption amount in the soil increases with the introduction of MMA and tBMA into the main chain, and decreases with the introduction of BMA into the main chain.

[0098] 4) Toxicity test on zebrafish (zebrafish purchased from Shanghai Feixi Biotechnology Co., Ltd., total length 2cm±0.5cm, weight 0.5g±0.1g):

[0099] Acute oral toxicity test for fish: referring to GB / T 31270.12-2014 Experimental Guidelines for Environmental Safety Assessment of Chemical Pesticides - Part 12: Acute Toxicity Test for Fish, a semi-static test method was used for zebrafish experiments to test the acute toxicity of polymethacrylate guanidine salts (test drugs) and benzalkonium chloride (BC) in aqueous solution to zebrafish in Examples 1 to 4. The specific experimental operation steps were as follows: first, a preliminary experiment was performed to determine the approximate toxic concentration range of the drug to zebrafish, and then a series of gradient concentrations of the drug were accurately set according to a certain interval. Seven zebrafish were placed in each concentration gradient, and the drug solution was replaced daily. Other experimental conditions were the same as those in the domestication environment. The growth of zebrafish was recorded at 96 hours, and the toxicity level (LC) of polymethacrylate guanidine salts of Examples 1 to 4 to zebrafish was calculated. 50 ), the test results are shown in Table 1.

[0100] Environmental toxicity test of drug-containing soil: 10 g of fresh experimental soil and the polymethacrylate guanidine salt (test drug) of Examples 1 to 4 and benzalkonium chloride (BC) were respectively prepared into 1 L of drug-containing soil suspension. At the same time, a control group of soil suspension without drugs was set up, stirred with a glass rod, and then allowed to stand for 12 hours. After the upper layer of the solution became clear, 7 zebrafish were placed in each group of soil suspension, and new soil suspension was replaced every day. Other experimental conditions were the same as those in the domestication environment. The growth of zebrafish was recorded at 96 hours, and the toxicity level of the drug to zebrafish after soil adsorption was calculated. The test results are shown in Table 1.

[0101] Table 1 Results of oral toxicity test for fish toxicity and environmental toxicity test for drug-containing soil

[0102]

[0103] It can be seen from Table 1 that the oral toxicity (LC) of the polymethacrylate guanidine salts (PG, PG-MMA, PG-tBMA and PG-BMA) of Examples 1 to 4 to zebrafish 50 ) is greater than 1mg / L and less than 10mg / L, which is considered poisoning, and the toxicity after interaction with soil (LC 50S ) is greater than 10 mg / L, showing low toxicity.

[0104] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. An application of polymethacrylate guanidine salt in preventing and treating banana wilt, characterized in that: The polymethacrylate guanidine salt comprises the following polymer segments: In the formula, R is a C1-C5 alkyl group or a benzyl group, x and y are both integers, 1400≤x+y≤2700, and the ratio of x to y is 1:0-1.

2. The use according to claim 1, characterized in that: The R is one of methyl, tert-butyl and benzyl.

3. The use according to claim 2, characterized in that: The ratio of x to y is 1:0.11-0.

5.

4. The use according to any one of claims 1 to 3, characterized in that: The polymethacrylate guanidine salt comprises the following polymer segments: In the formula, z is an integer ranging from 10 to 40.

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