Thermodynamic and Viscometric Studies on the Solution State of Surfynol 465 in Water
S. Sato, and H. Kishimoto. Bulletin of the Chemical Society of JapanVol.58 (, No.1):
The vapor-pressure depression, surface tension, density and viscosity of the aqueous solution of Surfynol 465, nonionic surfactant, α,α′-2,4,7,9-tetramethyl-5-decyne-4,7-diylbisω-hydroxy-poly(oxyethylene), were measured at various concentrations and 298.15 K, indicating cmc at 11–14×10−3 mol kg−1 and a second cmc at ca. 30×10−3 mol kg−1. From vapor-pressure depression, the association numbers of first and second micelles were approximately estimated at 4 and 13–16, respectively. From the results of density and viscosity measurements, the molar volume and Einstein's parameter, k, were calculated, respectively. The cohesion between the two hydrophobic chains in monomer was suggested by the analysis of molar volume. It was estimated on the molar volume and k of Surfynol 465 that the hydration of two hydrophilic poly(oxyethylene) chains is significant in monomer as well as micelles, but scarcely changes through micelle formation. The effect of concentration on k was discussed with respect to the shape and interaction of micelles.