Physical Properties in Aqueous Solutions for a Series of Alkyltrimethylammonium Salicylates (C12TA-Sal through C16TA-Sal): From a View Point of Drag Reduction

Compounds for a series of alkyltrimethylammonium salicylates (C12TA-Sal through C16TA-Sal) were synthesized. Their physical properties in aqueous solutions were investigated by conductometry, viscometry, vortex inhibition, viscoelastic recoil and swirling decay time from a view point of drag reduction. For critical micelle concentrations (CMC) obtained for a series of compounds by conductometry, it was found that a linear relation of the form, log(CMC)= 4.088﹣0.305*Nc (Nc: carbon number in the alkyl chain), holds. From the viscosity measurement, all the compounds showed viscosity increase above their CMC. Vortex inhibition was observed above the CMC for the compounds with the chain length longer than C13. Viscoelastic recoil was observed above the concentration of one and a half times the CMC for the compounds with alkyl chain length longer than C14.