Abstract
Ethoxylated nonionic surfactants were prepared by reacting polyethylene glycol and different fatty acids, such as lauric acid, myristic acid, and oleic acid. The chemical structures of these prepared surfactants were confirmed by high performance liquid chromatography and proton nuclear magnetic resonance. The surface tension of the synthesized surfactants was measured at ambient temperature and the critical micelle concentration values were obtained. In addition, the effectiveness of adsorption at liquid/air interface Гmax and minimum surface area were calculated. The present study investigates the effect of ethoxylated nonionic surfactant on depression of pour point fuels.