Sugar-based anionic surfactants: synthesis and micelle formation of sodiummethyl 2-acylamido-2-deoxy-6-O-sulfo-D-glucopyranosides

The following sequence of reactions has been employed to synthesize the tit le anionic surfactants: [GRAPHICS] where R=C7H15; C11H23; and C15H31, respectively, and Py refers to pyridine. Aggregation of the surfactants synthesized (predominantly alpha anomers) i n water was studied at 40 degreesC by conductivity measurements. Increasing the chain length of R decreases the critical micelle concentration (CMC) a nd the degree of counter-ion dissociation. The dependence of the Gibbs free energy of micellization and CMC on the length of R is similar to other ion ic surfactants, but the head-group, i.e., the sulfated sugar moiety is less hydrophilic than the structurally related group -(OCH2-CH2)(2)-OSO3-Na+, m ost probably because of intermolecular H-bonding in the micellar pseudo-pha se (C) 2001 Elsevier Science Ltd. All rights reserved.