Preparation and properties of new lactose‐based surfactants

A new group of nonionic saccharide‐based surfactants, N‐alkanoyl‐N‐methyllactitolamines (alkanoyl: decanoyl, lauroyl, myristoyl, palmitoyl, stearoyl), were synthesized and characterized. Surface properties such as critical micelle concentration, standard free energy of adsorption, standard free energy of micellization, surface tension reduction efficiency, effectiveness of surface tension reduction, surface excess concentration, and surface area demand per molecule as well as foaming properties (i.e., foam volume and foam stability), contact angle, antiraicrobial activity, and biodegradability were determined. The selected performance properties were evaluated in relation to commercially available alkyl polyglucosides (Glukopon 600 EC(HH)‐a Henkel product), and oligooxyethylenated decyl (C10E4) and dodecyl (E12E5) alcohols. The foaming‐stabilizing effect and contact angle suggest that the lactose‐derived surfactants that were studied share some common properties with alkyl polyglucosides that are different from those with an oligooxyethylene grouping. All tested N‐alkanoyl‐N‐methyllactitolamines were practically nontoxic to bacteria and yeasts. These compounds are readily biodegradable in the Closed Bottle test inoculated with activated sludge. N‐Alkanoyl‐N‐methyllactitolamines with lower chain lengths (C10–C14) biodegraded at a slightly faster rate. Biological properties showed that this class of compounds fulfills all requirements needed for environmental acceptance.