In the past forty years the interaction between synthetic nonionic hydrophilic polymers and ionic surfactants dissolved in water has been extensively studied. The poly(ethylene glycol) (PEG)/sodium dodecyl sulfate (SDS)/water is a typically important system and has been investigated through many different techniques [ 1]. The (polymer + surfactant) mixtures have important properties for a wide range of industrial application fields as floatation processes, foaming control, detergency, and enhanced oil recovery. Comparison between thermodynamic properties of surfactants in water and aqueous polymer solutions is interesting and helpful for the better understanding of polymer-surfactant interaction [2,3]. These have convinced us in studying the micellization behavior and evaluation of associated parameters of anionic surfactant SDS in (water + PEG mixed solvent) system. In this work, we present our results on density and sound velocity measurements of solutions of SDS in water and in aqueous solutions of PEG2000, PEG6000 and PEG 10000 over a range of temperatures at atmospheric pressure. The effects of polytner and tetnperature on the apparent tnolar volutne and isentropic cotnpressibility ofSDS are studied. From these data, the variation of the critical micelle concentration (CMC) of SDS in pure water and in aqueous PEG solutions with temperature was obtained. Parameters of the micellization of the investigated surfactant in the absence and presence of PEG are also estimated.
