Synthesis, stability, and biodegradability studies of a surface‐active amide

A homolog pure nonionic surfactant, tetra(ethylene glycol) mono‐n‐octaneamide, was synthesized. The surfactant was characterized by determining the critical micelle concentration, cloud point, and biodegradation. Hydrolysis catalyzed by an acid, an alkali, a peroxide, and enzymes [peptidase from porcine, amidase from Pseudomonas aeruginosa, and two lipases, Mucor miehei lipase (MML) and Candida antarctica lipase B (CALB)] was investigated using 1H nuclear magnetic resonance. The surfactant was stable toward the acid, alkali, and peroxide. When subjected to peptidase and CALB, the amide was cleaved, although at a low rate. No reaction was obtained when using the amidase or MML. The biodegradation test resulted in more than 60% degradation after 28 d. Based on these results, the amide surfactant can be considered chemically stable, yet highly biodegradable, which generally is an ideal combination of properties for a surfactant.