Synthesis and properties of sugar-based surfactants alkoxyethyl β-D-glucopyranoside

Abstract

Alkyl glycosides as modern industrial manufactured products are important. Furthermore, the better water solubility should make them a greater potential application value. In this study, an improvement of water solubility has been realized by adding the oxyethene fragment (−OCH2CH2) as a hydrophilic spacer to the conventional alkyl glucoside structure, and the excellent surface properties of the alkyl glucoside were still maintained. The amphipathic properties of the prepared alkoxyethyl β-D-glucopyranoside can be adjusted by the alkyl chain length (n). Alkoxyethyl β-D-glucopyranosides were found to be water soluble with n ≤ 10. For both of CMC and γCMC, there was a monotonous decreasing trend with increasing the alkyl chain length. Such amphipathic molecules adsorbed preferentially on the solution surface and then formed spontaneously micelles in the aqueous solution by the hydrophobic effect. Nonyloxylethyl β-D-glucopyranoside exhibited the finest foaming property, as well as the strongest emulsifying capacities in the rapeseed oil/water system and the toluene/water system. In addition, alkoxylethyl β-D-glucopyranoside (n = 9–14) had thermotropic liquid crystal property and thermal stability below 230 °C. Alkoxyethyl β-D-glucopyranoside, as a class of sugar-based surfactants, will be expected to be developed in a variety of practical application.