Preparation of surfactant from cardanol

Abstract

Cardanol obtained from decraboxylated cashew nut shell liquid was used for preparation of sodium cardanol sulfonate surfactant, by sulfonation of cardanol with fuming sulfuric acid at temperature of 10 ℃ for 2 hours and room temperature for 3 hours, and then by neutralization with sodium hydroxide at room temperature for 1 hour. Surfactant properties of cardanol sulfonate were determined and compared with dodecylbenzene sulfonate. Surface tension values were measured to be 32.3 mN/m for cardanol sulfonate at 20 % w/v and 28 mN/m for dodecylbenzene sulfonate at 15 % w/v. Critical micelle concentrations of 0.435 and 0.372 mol/l for dodecylbenzene sulfonate and cardanol sulfonate, respectively, were found. Using dodecylbenzene sulfonate as reference, the relative detergency of 93.7 % for cardanol sulfonate was obtained. Results suggest that cardanol sulfonate can be used as anionic surfactant.