Synthesis and Surface Properties of Oleyl Alcohol Sulfonate Branched-chain Surfactants

Abstract

Purposes Waste edible oil is a potential renewable resource, so it is of great significance to convert it into high value-added fine chemical products. Oleyl alcohol, as a product of selective hydrogenation of oleic acid, contains both C=C bonds and hydroxyl group in its molecule. Methods Oleyl alcohol sulfonate (OAS) was synthesized by sulfonation of C=C bonds in oleyl alcohol with sodium hydrogensulfite. The synthesized product was characterized by FTIR, HPLC, HR-MS, and NMR technique. The surface properties of OAS at (25±0.1)℃, including surface tension, wetting ability, and emulsification, were investigated and compared with branched oleate methyl oleate sulfonate and linear fatty acid methyl ester sulfonate. Findings The results showed that the expected structure was synthesized, and the resultant OAS significantly reduced the surface tension of water, had good surface activity (4.17×10-3 mol/L for CMC and 33.99 mN/m for γCMC), good wettability (contact angle as low as 61.7° on parafilm), excellent emulsification (emulsification time of 2.5 g/L solution is 423 s), and superior defoaming capacity. Conclusions The prepared OAS has the characteristics of branched-chain anionic surfactants and potential application in industrial hard-surface cleaning field.

Keywords

• oleyl alcohol
• sulfonate
• branched-chain surfactants
• surface tension
• hydroxyl group