Wheat protein-derived surfactants: Synthesis and properties

Abstract

Green surfactants produced from peptides and their derivatives have excellent surface chemistry and application properties. A mild, biocompatible, and rapidly biodegradable green surfactant, potassium N-lauroyl wheat peptide (PLW), was synthesized by an acylation method in the aqueous phase with lauryl chloride and wheat oligopeptide as starting materials. Furthermore, the isoelectric point, equilibrium surface tension, dynamic surface tension, micellar aggregation behavior, foaming, and irritating properties of PLW were studied. Wheat oligopeptides were discovered to have the greatest glutamic acid content, accounting for 30.92% of the overall amino acid composition. The findings revealed that the protonation and ionization behavior of PLW was pH dependent. At pH 8.5, water's surface tension was lowered to 32.1 mN/m⁻¹. At high concentrations and pH, PLW formed large aggregates in solution, causing the adsorption behavior of PLW molecules to shift from diffusion-controlled adsorption to mixed kinetic adsorption, with PLW exhibiting great surface activity. Furthermore, PLW has good foaming properties and is non-irritating. As a result, PLW is predicted to become widely employed in the field of household chemicals.