Influence of sulfonic acid group on the performance of castor oil acid based methyl ester ethoxylate sulfonate

Castor oil acid methyl ester ethoxylate sulfonate (CAMEES) is a new multifunctional anionic-nonionic surfactant with three hydrophilic groups. In this work, CAMEES was synthesized through reaction of castor oil acid methyl ester ethoxylate (CAMEE) with sodium bisulfite in the presence of tert-butyl peroxybenzoate as catalyst and ferric chloride as co-catalyst in solution of water and isopropanol. The sulfonic acid group has an important effect on the physicochemical properties of the surfactant. Compared to CAMEE, CAMEES exhibits better soybean oil emulsification, detergency, foam ability and stability. However, owing to the sulfonic acid group, the wetting ability and paraffin emulsification are more limited.