Preparation of Environmentally Friendly Amino Acid-Based Anionic Surfactants and Characterization of Their Interfacial Properties for Detergent Products Formulation

In this study, 2 types of amino acid-based biosurfactants such as potassium cocoyl glycinate (CGK) and sodium cocoyl glycinate (CGN) were synthesized from coconut oil. Their chemical structures were identified using FT-IR, H-1 NMR, and C-13 NMR spectroscopies. Characterization of their interfacial properties has shown that both CGK and CGN surfactants are surface-active and effective in reducing interfacial free energy. Washing test results indicated relatively good detergency compared with surfactants commonly employed in detergent applications. From environmental compatibility tests, both CGK and CGN are found to be readily biodegradable, nontoxic, nonirritating, and very mild. In particular, the CGK surfactant was found to be more efficient in reducing interfacial free energy since a larger number of CGK molecules are preferentially adsorbed at the air-water interface due to higher hydrophobicity and larger mobility of CGK than CGN, indicating possible uses in detergent applications.