Study On The Properties Of Polycarboxylates And Polynaphthalenesulfonate Dispersants In Pesticide Formulations

We studied the surface properties of polycarboxylate dispersant(SD-819)and polynaphthalene sulfonate dispersant(SD-661)in aqueous solution.The results showed that dispersant SD-819 have small surface tension(?cmc),critical micelle concentration(cmc),micelle formation free energy(?Gmic)and bigger adsorption quantity in aqueous solution compared with the dispersing agent SD-661.Meanwhile,we investigated the effect of the amount of dispersant acting on 500 g / L prometryn suspension concentrate(SC)and 75% tribenuron-methyl water dispersible granules(WDG).It was found that the zeta potential and the adsorption quantity of the prometryn SC increased gradually with the addition of single dispersants,and the viscosity,particle size and water separation rate were decreased.The zeta potential and the suspension rate of the tribenuron-methyl WDG are gradually increased,and the disintegration and wettability are reduced.It indicated that the two types of dispersants used in water-based dosage forms of SC and WDG have similar regularity.By the screening of dispersants,thickeners and antifreeze,we prepared the best formula of 500 g / L prometryn SC and have better performance compared with the same type of abroad dispersant.Similarly,the best formulation of 75%tribenuron-methyl WDG was prepared by screening the dispersant,wetting agent and disintegrating agent,and the performance was better than commercially available dispersant.In addition,We make a theoretical analysis by applicated dispersant SD-819 and SD-661 for prometryn SC and Benzenesulfuron-methyl WDG,which provided some theoretical support for the rapid screening and dosage of water-based pesticide formulation.