Efficient solvent-free cationization of alkylpolyglycoside based surfactant compositions using natural glycine betaine

We describe here a new strategy for the preparation of 100% bio-based sugar based cationic surfactants using glycine betaine butyl ester as the cationizing agent. We first studied NaHCO₃-catalyzed transesterification reactions of pure fatty alcohols and equimolar mixtures of alkyl glucosides or xylosides and fatty alcohols. Using solvent-free processes, moderate to high levels of cationization (48-90%) concerning both fatty alcohols and carbohydrates, were obtained with a certain regioselectivity toward C6 and/or C3 positions in the d-glucose and d-xylose series. This synthetic approach can also be extended to commercial alkylpolyglycosides containing large proportions of fatty alcohols (90-96%) to provide original cationized glycoside compositions, as (co-)emulsifiers.