Selective Syntheses and Properties of Anionic Surfactants Derived from Isosorbide

Abstract

Two series of anionic surfactants (endo-5-O-alkyl isosorbide-2-O-propyl sulfonic acid sodium salt and exo-2-O-alkyl isosorbide-5-O-propyl sulfonic acid sodium salt) with straight alkyl chains (hexyl, octyl, decyl, and dodecyl) were synthesized from isosorbide derived from biomass, through steps of allylation, alkylation, and sulfonation. The selectivity and efficiency of the reactions were optimized by adjusting the solvent, catalyst, reactant molar ratio, and temperature. The product 2-O-allyl isosorbide was obtained with a yield of 81% and selectivity of 23:1 (endo:exo), and 2-O-alkyl isosorbide was obtained with a yield of 72% and selectivity of 24:1 (exo:endo). The synthesized anionic surfactants were characterized using the critical micelle concentration (CMC), surface activity, emulsion stability, foaming height, and the Turbiscan Stability Index. The CMC decreased with increasing alkyl chain length. The properties of endo form and exo form were compared.