The effect of emulsifier on the physical stability of beta-cypermethrin 45EW

The effect of emulsifier on the stability of beta-cypermethrin 45EW,such as emulsifier kinds and content,the HLB value and structure of emulsifier was studied.The results showed that qualified,stable emulsion in water could be prepared emulsifier selected in a certain range.There was a close relationship between HLB value and particle size and distribution.Particle size and distribution will be changed as the HLB value of emulsifier changed,HLB adjustment can affect the stability of EW.In certain extent,particle size became small,particle distribution became narrow,and stability improved with the increase of emulsifier content.Particle size can be used as an important parameter in the selection of optimum emulsifier content.The anti-coalescence of emulsion stabilized existed correlation with the structure of emulsifier,it would be improved with the length of the saturated carbon chain of lipophilic group.