Evaluation of the application performance of several domestic surfactants in suspension concentrate

In order to evaluate the application performance of some domestic polymeric surfactants in pesticide formulations processing, the surface properties including critical micelle concentration (CMC), surface tension and wetting time and etc were investigated. Based on these performance parameters determined, preliminary estimation on whether the surfactants were suited for wetting agents or dispersants was made. The dosage and ratio of various additives in carbendazim suspension concentrate (SC) was determined using flow point method. Then processing and validation test on carbendazim 500SC with different contents of surfactants was examined.The results showed that determination of the additives contents in SC through flow point assay of the mixture of wetting agent and dispersant solution mixed proportionally is completely feasible. Both dosage of flow point and 5 times dosage can process qualified samples successfully. According to the recommended concentration of pesticide registration, dilute the formulation by 1 000 times and determine its liquid surface tension, contact angle of the wheat leaf and liquid holdup of the formulation to direct the field application. The results showed that liquid surface tension is too large to wet wheat leaves. It was indicated that the performance of samples prepared with both domestic and oversea additives had no obvious differences. Several domestic additives showed better performance than oversea counterparts. Application of polysulfonate and polycarboxylate surfactants cooperatively represented superiority in the preparation of suspension concentrate.