Surface activity and emulsification properties of hydrophobically modified dextrins

Novel modified dextrins were prepared in which propylene glycol polyglucosides are reacted with various fatty alcohols (C10–C18). We measured the surface activities of these compounds in terms of the critical micelle concentration (CMC), the surface tension at the CMC (γcmc), the surface excess concentration, the surface area occupied per molecule, and the standard free energy of micellization per mole of monomer unit (ΔG°m). Emulsification measurements revealed that the smallest emulsion droplet size (i.e., most stable emulsion) was also obtained when the number of carbon atoms in the alkyl chain was 14. The biodegradability of the modified dextrins was also compared to that of sodium dodecylbenzene sulfonate and octyl phenol ethoxylate and it was found that the compound possessed the more highly biodegradable.