Studing On The Physical Stability Of Dichlorbenzuron 20% SC

In order to grope for stabilization mechanism of SC, This thesis chose dichlorbenzuron as the research objects. Through the formulation selection and many kinds stabilization experiments, we did more research about the influence factors of suspension concentrate forming mechanisms. The following aspects were studied in this thesis:1 In this paper, We have screened out the dispersant antifreeze,thickener and defoameragent by measuring the particle size and stability of different formulations of dichlorbenzuronin water, then the best formula of dichlorbenzuron in water was ascertained as follows: dichlorbenzuron:20wt%; NNO:2%-3wt%; Antifreeze ethylene glycol: 2.0wt%; Thickener XG :0.20wt%; Defoameragent : 0.1wt%; The rest was water.2 We studied the dispersion stability of 20% dichlorbenzuron water suspension concentrate, The results showed that Hydrogen bond is important force in the combination,Electrostatic exclusion. The adsorption of NNO dispersant on the surface of dichlorbenzuron particles the fitting Langmuir equilibrium, particle sizes decreased with the increase of the dispersant molecular weight,the saturated adsorption of NNO dispersant on the surface of dichlorbenzuron particles increased with the increases, of dispersant molecular weight. The adsorption state is multipoint adsorption, lies between vertical and level. With the increase of the dispersant molecular weight of NNO, the longer of molecular chain, the more of sulfonic group in each molecular, the more surface charge of particles, absolute value ofζpotential increased.3 We studied the dispersion suspension stability of 20% dichlorbenzuron water suspension concentrate, The results showed that 20% dichlorbenzuron water suspensions show yield pseudoplastic fluid characters , conform to Casson model and have good thixotropy. when the pH value beteewn 4.0 to 8.0, the system can keep good storage stability. viscosity of the system had been increased obviously with the addition of salt ions, the concentration of critical flocculation showed decreased. xanthan gum with negative charge, can increase obviously the yield stress,viscosity and thixotropy of dichlorbenzuron water suspensions.The dependence of viscosity on time of the system showed increased with the amount of xanthan gum.