Functional Evaluation And Optimization Of40%Chlorothalonil Suspension Concentrate

TERSPERSE(?)2700is the overseas imported dispersing agent, specifically for preparing suspension concentrate. The SC containing TERSPERSE(?)2700has the good performance of dispersion, but the price of TERSPERSE(?)2700is too expensive. In order to seek for the domestic moderately-priced additives, this article takes40%Chlorothalonil SC as the object of study, and it makes the contrast to the performance of six kinds of domestic dispersing agents. Thickening agent and thixotropic agent are also important additives for SC, and they play an important role in keeping the SC stability and preventing the suspended particles from staying together. Through the formula study of dispersing agent, thickening agent, thixotropic agent and processing technic,40%Chlorothalonil SC is obtained. The study provides new ideas for the next step of development and application of FS. The following results have been obtained:1. Comparing6kinds of dispersing agents with TERSPERSE(?)2700separately in the performance of flow point, CMC, HLB and so on, we can find201107and201108have similar performances with TERSPERSE(?)2700. Matched with1004, they all have good performance of dispersion and stability. When4kinds of Carboxylic acid salts dispersants are close to CMC, they reduce the water’s surface tension basically in the same degree. When the content applied is4%, the dispersing performance is quite good. Among them, the dispersing performance is worst, when using GY-D1252and GY-D1256. Therefore, the dispersants are201107or201108. When using them and wetting agents TERWET(?)1004in the ratio of2-1, then mixing the additives and40%of chlorothalonil SC in the content of6%, the SC has a good peformance of dispersion and wettability, and its storage stability also gets improved.2. Through screening the concentration and amount of the three kinds of viscous agents, when xanthan gum used is0.2%, the SC system has a good flow properties, with the viscosity of489.1mPa.S, and hot storage chromatography rate of water is2%; when Bentonite used is1%, the SC has a good performance of liquidity and dispersancy, with no water separated out. Through mixing the screened dispersant201107or2011084%, viscous agent xanthan gum0.2%, bentonite1%and chlorothalonil, process40% chlorothalonil SC, and the physical and chemical performances of the system conform to the state standards.3. Under the same concentration, the viscosity of xanthan gum is239.87mPa. S, and the viscosity of sodium carboxy methyl cellulose and polyvinyl alcohol (pva) are separately23.89mPa. S and4.56mPa. S. Therefore, xanthan gum has the biggest influence on the viscosity of suspension system. Three kinds of viscous agents all show a thin shear of non-newtonian fluid. Through the analysis of rheological properties of the40%chlorothalonil SC system, we can conclude that different kinds of dispersing agents, the rheological character of suspension system is different. When Xanthan gum dosage is0.2%, the viscosity and rheological properties of the suspension system are the best.