Synthesis and surface activity properties of symmetric double chains alkylbetaine surfactants derived from s-triazine

A series of symmetric double chains alkylbetaine surfactants BCn–n (n = 8, 10, 12, 14) were synthesized from cyanuric chloride, aliphatic amines, N,N-dimethylpropane-1,3-diamine and sodium chloroacetate. Their structures were confirmed by MS, TOF-MS, 1H NMR, 13C NMR and FTIR. Surface tension measurements demonstrated that BC8–8 and BC10–10 have superior surface activity compared with corresponding conventional surfactants with lower CMC and γcmc. Additionally, interface behaviors of the four surfactants including adsorption and micellization can be reflected by Amin, pC20 and the calculation of the standard free energy of micellization (ΔGmicθ) and adsorption (ΔGadsθ).

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► Four novel surfactants derived from s-triazine were synthesized and characterized.
► They exhibited superior surface activity with small CMCs and γcmc.
► The surfactants showed great ability to adsorb at the air–water interface.
► The surfactants BC8–8 and BC10–10 were superior to conventional surfactants.