The Preparation Of Water-Based Ultra Low Volume And Mirco-Emulsion

With the development of modern agriculture and related technology,labor saving,high efficiency pesticide application technology has become the inevitable trend of agricultural production.The use of unmanned aerial vehicle is one of the emerging agricultural technologies andthe further development of mechanized plant protectionwith high security,high efficiency,wide adaptability and other advantages,has been widely used.However,the current pesticide formulations used inunmanned aerial vehicle applications are still EC,suspension concentrate,micro-emulsion,emulsion oil in water and other traditional formulations,but the report of using these traditional formulations having poor control have been reported.Thinking of the unmanned aerial vehicle's limited load,the dilution factor will be low when watered,and the stability of some preparations may occur at low dilution.We measured the stability,volatilization rate and suspension rate of 44 formulations on the market at low dilution.On this basis,we developed two different micro-emulsions and create a new pesticide formulations water-based ultra-low-volumeon the basis of ultra-low-volume agent.1.The emulsion's stability of pesticide formulations in dilutionIn this study,the stability,evaporation rate and suspension rateof different dilution emulsions in the range of 6.25 times-200 times dilution were determined for the 44 kinds of pesticide formulations.The pesticide formulations include emulsifiable concentrates,micro-emulsions,emulsion in waters,soluble concentrates,aqueous solutions,water dispersible powders,wettable powders,suspension concentrates.In view of the stability of the diluted emulsion,threeof the 26 liquid formulations'emulsion stability were found unqualified of all dilution in the range of 6.25 to 200 times,indicating that these products' stability were unqualified;Seven products' emulsion stability were qualified at a dilution of more than 25 times(including 200 times),but were unqualifiedbelow 25 times dilution,and the remaining 16 products were qualified for emulsion stability in various dilutions.Low-dilution of emulsion instability products when used in UAV operations may affect the control effect.In the evaporation rate determination,only one product's dilutedemulsion volatilization rate was less than 30%,the remaining product's diluted emulsion volatilization rate are more than 30%.In UAV operation,when the volatilization rate is high,may affect the droplet drift and settlement.In the suspension rate determination,there are some product formulations' emulsion suspension rate is lower than the national standard in some dilution times;These results indicate that some of the conventional formulations products may be problematic when used directly in UAV plant protection operations.2.Preparationof micro-emulsionThis study screened the formulation of 12%beta-cypermethrin·emamectin benzoate micro-emulsion and 25%chlorpyrifos·emamectin benzoate micro-emulsion,and did the quality test of the trial products.Aiming at the development of these two kinds of mixed micro-emulsions,the varieties and proportions of solvent,surfactant and cosurfactant were optimized,according to the dissolved state of the solvent,appearance of the preparation,stability,transparent temperature range and other indicators,Finally we got the two micro-emulsion formulations:12%beta-cypermethrin·emamectin benzoate micro-emulsion:10.5%of beta-cypermethrin,1.5%ofemamectin benzoate;solvent:15%of cyclohexanone;surfactant:8%of Emulsifier 500,12%of Emulsifier 603;co-surfactant:4%of butanol;add water to make up to 100%.25%chlorpyrifos·emamectin benzoate micro-emulsion:24%of chlorpyrifos,1%of emamectin benzoate;solvent:4.5%of xylene,0.5%of cyclohexanone;surfactant:6%of EL-60,6%of Emulsifier 603,6%of Emulsifier 500;cosurfactant:3%of n-butanol;add water to make up to 100%.Then we did the quality test of the optimized formulation of the product,including of pH,persistent foaming,diluted emulsion stability,low temperature stability and heat storage stability.All the results were satisfied with the national standard.And the emulsion stability is good at low dilution.3.Preparation of water-based ultra low volumeFor the ultra-low-volume can not be directly used for UAV spray,this study attempts to develop the water-based ultra-low-volume formulation to replace the organic solvent with water,and this formulation developed based on the emulsion in water.According to the appearance of the formulation,stability and other characteristics,we screened the varieties and ratio of the solvent,surfactant and antifreeze,especiallythelong-chain alcohol which can prevent droplets'volatilization.After the optimization,finally we got the formulations:6%beta-cypermethrin water-based ultra low volume:5.25%of beta-cypermethrin,0.75%ofemamectin benzoate;solvent:18%of No.150 solvent oil,2%of cyclohexanone;surfactant:4.5%of Emulsifier 601,5.5%of LAS-30,0.24%of Emulsifier A;antifreeze agent:2%of glycerol;3%of long-chain alcohol A;add water to make up to 100%.By comparing the three processing methods,it was determined that the D-phase emulsification method was used to process this formulation.As the water-based ultra low volume is a new formulation,there is no quality standards,so we need to do the quality test according to the similar formulations.Referring to the quality standard of emulsion in water and ultra-low-volume,we have carried out pH measurement,dumping measurement,persistent foaming measurement,diluted emulsion stability,cold storage and heat storage.The results are all meet with national quality standards.Low dilution emulsion stability qualified,and the emulsion volatilization rate is less than 30%,is suitable for unmanned aerial vehicle plant protection.