Synthesis and surface properties of branched-chain tertiary fatty alcohol sulfate surfactants

Abstract

Abstract In this paper, anionic branched-chain tertiary fatty alcohol sulfate surfactants were synthesized from n-hexene and n-octene using selective olefin dimerization, hydration reaction (hydroxylation), and sulfur trioxide sulfation. The direct hydration reaction of the α-olefin dimer 2-butyl-1-octene with water as a model reaction was explored for the synthesis of branched-chain tertiary fatty alcohols. Two branched-chain tertiary fatty alcohol sulfate surfactants, namely C12-SBTAS and C16-SBTAS, with different carbon chain lengths, were synthesized by the sulfur trioxide sulfation method. Their structures were confirmed by various analytical techniques, including HPLC, FT-IR, HR-MS, and 1H NMR. Equilibrium and dynamic surface tension, foaming, wetting, and emulsifying properties were compared with those of Guerbet cetyl alcohol sulfate (C16-SGAS). C12-SBTAS and C16-SBTAS exhibited good surface activity with equilibrium surface tension (γ CMC) values of 27.41 mN m−1 and 26.69 mN m−1, respectively. They also had low foaming and rapid defoaming abilities, as well as good wetting and emulsifying properties, which match the application characteristics of typical branched-chain surfactants.