New alquil amide type cationic surfactants from arginine

Abstract

The synthesis, stability, surface activity and antimicrobial properties of a new family of cationic surfactants (the long chain arginylalkylamide dihydrochloride salts) derived from the condensation of the amino acid arginine and a long chain alkylamine are described. The surface active parameters reported are c.m.c. (critical micellar concentration), pC₂₀ (negative log of the surfactant molar concentration required to reduce the surface tension of the solvent by 20 mN m^–1), γ_c.m.c. (the surface tension at the c.m.c.), Γ_max (the maximum surface excess concentration) and A_min (the minimum area per surfactant molecule at the interface). These data and those obtained from the evaluation of the antimicrobial properties are compared with the data corresponding to another family of cationic surfactants reported earlier by our group: the long chain N ^α-acylarginine methyl ester salts.

Moreover, the synthesis of analogues possessing a reactive group capable of bonding to wool or cotton fibres is described: the long chain N^α-dichlorotriazinylarginylalkylamide monohydrochloride salts. We expect these compounds to bond to the textile substrate by the formation of a covalent bond. Confirmation of this is, however, necessary.