Abstract
The anionic surfactants developed recently, alkanamide poly (oxyethylene) sulfates, are supposed to be more mild in the skin irritating action than the surfactants such as alkyl poly (oxyethylene) sulfates used conventionally in practice as a principal constituent of the household liquid detergents, shampoos and so on. In the present work, with the intention of investigating the practicability of these new surfactants the solution viscosities have been measured to depict the isoviscous curves on the triangular diagrams for the ternary systems, sodium alkanamide poly (oxyethylene) sulfate/N, N-diethanoldodecanamide (thickener) /water. Consequently, the following informations were obtained.
(1) While, with increase in number of oxyethylene unit in the surfactant molecule, the high viscosity region extends toward the water corner, it is shifted to higher concentration of thickener and the highest viscosity falls down. In other words, the thickening effect of N, N-diethanoldodecanamidelowers.
(2) Among three samples of different alkane chain lengths, dodecan-, tetradecan- and hexadecanamide poly (oxyethylene) sulfates, in the case of tetradecanamide the thicking effect is most remarkable and the solution of the utmost viscosity is obtainable.
(3) In the case of sodium dodecyl poly (oxyethylene) sulfates, with increase in number of oxyethylene unit the highest viscosity falls down in a simillar manner, but the high viscosity region is shifted to lower concentration of thickener contrary to above.
