The Effect Of The Mixed System Of Polyoxyethylene Ether And Polycarboxylate On Suspension Concentrate

As an important component of pesticide preparation,surfactants can greatly improve the efficacy of pesticides,reduce the amount of pesticides used,and have an important impact on the stability of pesticide formulations.In this paper,we have study the effect of polycarboxylate dispersants and polyoxyethy leneether dispersants compound and the application in the suspension concentrate.At first,this paper mixed the polycarboxylate dispersant SD-840 and polyoxyethy leneether dispersant 601 P are combined according to different quality ratios.And than we measured the surface tension for the single one and the associative compound.We also analyzed the change of surface performance and the interaction between polycarboxylate dispersants and polyoxyethy leneether dispersants through correlated calculation.We have use these mixed surfactants to prepare 430 g·L-1Tebuconazole SC and 350 g·L-1 Imidacloprid SC,and compare the effects of different mixed ratio.The changes of the particle size,suspension rate,Zeta potential,Water separation rate,viscosity,and rheology of samples before and after the thermal storage were carefully investigated.The results showed that the suspension stability of 430 g·L-1 Tebuconazole SC and 350 g·L-1Imidacloprid SC obtained by the mixed system was superior to that of SC prepared by only SD-840 or 601 P,respectively.Especially,the SC obtained by the mixed system with a 0.75 mass ratio between SD-840 and 601 P exhibited the superior suspension stability and minimum variation of particle size and suspension rate before and after thermal storage.And we mixed the polycarboxylate dispersant SD-840 and fatty alcohol polyoxyethy leneether(EO number are 5)with different carbon chain lengths.Then we measured the surface tension for the associative compound.We also analyzed the change of surface performance and the interaction between polycarboxylate dispersants and fatty alcohol polyoxyethy leneether dispersants through correlated calculation,as well as the interaction relationship between the two dispersants after the compounding.The compound dispersant was applied to 25% Pymetrozine SC,the changes of the particle size,suspension rate,Zeta potential,Water separation rate,viscosity,and rheology of samples before and after the thermal storage were carefully investigated.And compared with the commercially available 25% Pymetrozine SC,the 25% Pymetrozine SC prepared when the carbon chain length was 9 was better,more close to the market level.