Syntheses and surface active properties of cationic surfactants having multi ammonium and hydroxyl groups

In this study, cationic surfactants having mono-, di-, and tri-amminium groups were synthesized by the condensation reaction of alkyl glycidyl ether and alkyl amine followed by the quarternization with dimethyl sulfate. The structure of the product was elucidated by 1H NMR and FT-IR. The minimum surface tension achieved using C12-BHDM surfactant was around 28.88 mN/m, which suggests that C12-BHDM can be used to reduce the surface tension of primarily aqueous formulations and to act as emulsifiers. Dynamic surface tension measurement using a maximum bubble pressure tensiometer indicated that much longer time was required to reach an equilibrium value presumably due to the low mobility rate of a surfactant molecule with high molecular weight. The interfacial tensions measured between 1 wt.% surfactant solution and n-decane were found to be in the same order of magnitude as those exhibited between micellar solutions and nonpolar hydrocarbon oils. It has been observed that the results for foam stability measurement are consistent with those of CMC and contact angle. That is, the percentage of foam volume decrease has been observed to increase with an increase in number of ammonium and hydroxyl groups.