Formulation And Rheological Analysis Of Pesticide Waterborne Liquid Formulation

With enhancement of environment protection consciousness of people, pesticide formulations are developing towards the water-based ones. Suspension concentrates(SC) and Suspoemulsion(SE), which are two of the most popular water-based formulations, have high efficiency, good security and environmental compatibility. In this paper, five kinds of suspension concentrates were prepared by five kinds of novel domestic surfactants, then screened the optimal formulations. The optimal formulations solve physical storage stability problems of SC including of creaming, water separating out. 40% thiram-SYP-2048 SE was prepared using new type of domestic surfactants and environment protecting solvents. Moreover, its optimal formulation was screened, and solved the physical storage stability problems such as Ostwald ripening.This paper analyzed the physicochemical parameters(γcmc, CMC, △Gmic, Гcmc, Acmc,△Gad) of surfactants(Tersperse®2700, SD816, SD819, SD661, SD818, SD815, SD811, SR206).The results are as follows: the surfactants can drastically reduce the surface tension of water. Their surface tension at critical micelle concentrate(CMC) were 44.1 m N/m, 49.4m N/m, 50.8 m N/m, 49.8m N /m, 57.3 m N/m, 51.3 m N/m, 43.2 m N/m and 43.9 m N /m, respectively.The CMC of SD816 and Tersperse®2700 are approximately 0.0049mol/L, and the values of △ Gmic of SD816, SD819 and 2700 are similar, suggesting that the micelle formation are roughly in line with trend.Five kinds of SC(25% pyraclostrobin SC, 500g/L prometryne SC, 30% thifluzamide-tebuconazole SC, 720g/L chlorothalonil SC, 430g/L tebuconazole) were prepared using novel domestic surfactants SD816, SD811, SR206, SD815, SD661. Furthermore, the optimal formulations were screened through the flow point method, zeta potential and rheological method, the results showed that surfactants(SD815, SD816, SD811) generally applicable to chiorinated organic pesticide, such as pyraclostrobin, prometryne, tebuconazole and so on.Moreover, we prepared 430 g/L tebuconazole SC using the same formulation, and the tebuconazole pesticide from two different manufacturers. The result shows that the formulation are broad-spectrum.The 40% thiram-SYP-2048 SE was prepared using novel domestic surfactants(SD816, SD661, SR206, SE213, etc), different solvents(SDRJ-1, trimethylbenzene, toluene, xylene, DMF). Furthermore, the optimal emulsifier combination was screened through HLB value and rheological properties(viscosity curve, yield stress and strain scanning analysis). Compared with rheological properties of different solvents to screen SDRJ-1. The formulation can reduce the viscosity of SE from 8000 mpa.s to 324 mpa.s. The suspension rate of the 40% thiram-SYP-2048 SE is 95% and the pesticide particles have no flocculation via SEM. The formulations are promising market.