| This paper takes pesticide special surfactants that are supplied by "twelfth five-year" science and technology support plan as the research object. After making preliminary judgement to their wetting or dispersing performance through the representation of their physical and chemical properties, the adjuvants application performances were evaluated through processing relevant pesticide preparations and determining key quality indicators of these preparations. Then select sample with good properties and measure the data of dilution’s surface tension and liquid holdup on crop leaves under the recommended concentrations in the field use, so as to simulate and evaluate of their field use effect. The main research contents and results are as follows:1. The representation of physical and chemical properties the pesticide surfactants were divided into wetting agent and dispersing agent through measuring their properties, such as critical surface tension, critical micelle concentration, wetting canvas pieces of time and the emulsifiablity on xylene. The results showed that Terwet1004(contrast), GSS260, GSS451, GSS460, GSS462, AEOSS7, Gemini, KR-06, P-70and P-90were wetting agents and Tersperse2700(contrast), Morwet D450(contrast), GY-D1252, GY-D1256, LG-3, KY-816, GCL4-1,201107and201108were dispersing agents.2. Pesticide formulation process of75%chlorothalonil WP and70%imidacloprid WG In order to compare the performances of the new domestic dispersing agents, designing to use2%Terwet1004as wetting agent in two formula to eliminate the influence of wetting agent. Then respectively design dispersant with three gradient concentrations and the other components are the same.70%imidacloprid WG were prepared after adding adequate water between11%-13%in accordance with specific conditions in granulation.3. Use flow point method to determine the compatibility and dosage between wetting agents and dispersing agents in50%carbendazim SC Determine additive amount of auxiliaries in carbendazim suspension concentrate by flow point method. Calculate the dosage of auxiliaries according to the flow point and make sure whether it can process qualified formula or not under the dosage of auxiliaries through the preparations assessment of key quality indicators. Meanwhile, repeat processing with auxiliaries expanded to five times dosage of flow point and evaluate the process. The results show that using flow point method to determine the dosage of wetting agent and dispersing agents is feasible and suspension concentrate samples can be successfully processed with the dosage of flow point of additives.4. The determination of600g/L imidacloprid SC formulation by orthogonal design method Select three kinds of wetting agents:GSS260, GSS451, AEOSS7and three kinds of dispersants GY-D1252, GY-D1256, KY-816, and respectively configure the mass fraction of5%aqueous solution. Then measure their flow point to imidacloprid and choose the best wetting agent and dispersant. And then select one wetting agent and two kinds of dispersants and use orthogonal design test to screen600g/L imidacloprid SC formulation. Experimental results show that domestic fertilizer by orthogonal method can be successfully processed into600g/L imidacloprid SC.5. Quality test of processed preparation sample After processing the preparation sample, measure several kinds of key quality parameters according to the relevant standards. All the samples of75%chlorothalonil WP are measured with the key quality parameters, such as wetting time before and after the thermal storage, effective composition content and suspension rate. All the samples of70%imidacloprid WG are measured with the key quality parameters such as disintegration before and after the thermal storage and suspension rate.50%carbendazim SC is measured with the key quality parameters such as particle size, change of appearance, water dispersion, viscosity, active ingredient content and suspension rate before and after the thermal storage. The quality tests show that the performance of most samples is similar to contrast additives samples except individual formulation.6. The test of application performance of part of the samples Select some samples with good performance and dilute these samples according to the recommended concentration in the field. The surface tension, contact angle and the liquid holdup on plant leaves are measured. The results show that the surface tension is too high after dilution and the contact angle is more than100°. It will lead to large scale run-off when sprayed in field. Therefore, it is suggested that adding moderate spray fertilizer to increase effective utilization of liquid in practical application. |
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