Fundamental Properties of Aqueous Solutions of Nonionic Surfactants Prepared from Oleic Acid of High Purity

Fundamental properties such as micellar weight, critical micelle concentration and cloud point were determined for aqueous solutions of polyoxyethylene (20) sorbitan monooleate (POESO) and polyoxyethylene (n) oleyl ether [POEOE and POE (10) 0E for n=20 and 10, respectively] recently prepared from oleic acid of high (>99%) and low purity. HPLC analysis and measurement of hydroxy value were conducted to clarify the distribution of the oxyethylene chain. For POESO and POEOE, no significant correlation between the above properties and oleic acid purity could be found. For POE (10) OE, however, the cloud point was higher for greater purity. This was confirmed by the temperature dependence of light scattering intensity.