Preparation and characteristics analysis of 70% synergistic imidacloprid water dispersible granule

With Rolling-extrusion granulation method,the optimum formulation of 70% synergistic imidacloprid water dispersible granules(WG) was screened.In addition,effects of synergist piperonyl butoxide(PB) on the thermal stability,surface tension and biological activity of the formulation were studied.The optimum formulation to prepare 70% synergistic imidacloprid WG were imidacloprid ammonium technical(71.9%),synergist PB(1.0%),MORWET-EFW(2.5%),MORWET D-425 or Tesperse 2700(5.0%),disintegration agent ammonium sulfate(3.0%),polyethylene glycol as a binder(2.0%),and carrier m(silica):m(kaolin)=1:4 (14.6%).The bioassay showed that the biological activity of imidacloprid WG with 1% PB was 6 to 7 times as high as that of WG without 1% PB.With good dispersion and a very significant synergies,the suspension rate of the WG with 1.0% PB was over 90%.Degradation composition rate of the WG with 1.0% PB was 1.27% after heat storage at(54±2) ℃ for 14 d and its surface tension was no obvious change.