Synthesis and properties of geminis with two alkyl and two phosphate headgroups

Abstract

AbstractAmphipathic compounds having two phosphate groups and two long‐chain alkyl groups were prepared by a two‐step process: (a) preparation of monoalkyl phosphate from pyrophosphoric acid and dodecanol, (b) preparation of bis‐phosphoric acid from monoalkyl phosphate, (CH3)4NOH and 1,6‐dibromo hexane by using acetonitrile as solvent. The experimental results showed that a 5 : 10 : 2.5 molar ratio of reactants (alkyl phosphate/(CH3)4NOH/1,6‐dibromo hexane) and 3 h duration was the optimum for the reaction. The structure of the synthesized product was verified by analytical methods, viz. FT‐IR and 1H‐NMR. The surface‐active and performance properties like foaming, wetting and anionic content of the disodium salt of bis‐phosphoric acid were also evaluated. The synthesized anionic gemini surfactants possessed maximum anionic content, i.e. 73.4%, and showed better water solubility, foaming and wetting ability than conventional monoalkyl phosphates.