Synthesis of fatty acid diethanolamide was carried out by the condensation of diethanolamine with lauric acid, decanoic acid and octanoic acid in the presence of Novozym 435. The influence of solvent, time, temperature and agitation on the reaction rate was studied. Formation of lauroyl diethanolamide was complete in 6h in acetonitrile at 50° C whereas in toluene the reaction was not complete in 6h. Increase of reaction temperature from 50° C to 70° C increased the reaction rate. Proper agitation of the reaction mixture enhanced the reaction rate. Reaction in solution appeared to be more efficient than the reaction in solvent free system. The surface active property of the fatty acid amides was studied by determining their critical micelles concentration. The critical micelle concentration of lauroyl diethanolamide, decanoyl diethanolamide and octanoyl diethanolamide were found to be 0.63mM, 1.10mM, 1.45mM respectively in deionized water. Micelles of lauroyl diethanolamide were less than 1µm in size.
Semblante, G., Chua, M., & Chakraborty, S. (2009). Biocatalytic Synthesis of Diethanolamide Surfactants Under Mild Reaction Conditions. Philippine Journal of Science, 138 (1), 49-54.