Publication Details
Abstract
Cottonseed oil was employed as a renewable raw material for the synthesis of nonionic surfactants via amidation of fatty acids with diethanolamine. The reaction was conducted under solvent‑free conditions using alumina as a catalyst, yielding N,N‑bis(hydroxyethyl)alkanamides with high efficiency (93–97%). The synthesized surfactants were characterized by gas chromatography, infrared spectroscopy, and nuclear magnetic resonance, confirming the presence of amide linkages and hydrocarbon chains. Physicochemical properties were evaluated through surface tension, cloud point, and critical micelle concentration (CMC) measurements. The surfactants demonstrated effective surface activity, reducing surface tension to 43.2 mN/m and forming micelles at relatively low concentrations (CMC₁ = 15.6 mg/L, CMC₂ = 31.2 mg/L). A cloud point of 57–59 °C indicated favorable solubility and thermal stability. These findings highlight the potential of cottonseed oil–derived diethanolamides as sustainable surfactants for applications in oil recovery, cosmetics, and related industries.