VAPOR-PRESSURE OF PHENETHYL ACETATE IN THE SYSTEM WITH WATER, AND POLYOXYETHYLENE, 4, LAURYL ETHER

The phase diagram was determined for the system water, phenethyl aceta te and a commercial surfactant, laureth 4 (Brij(R) 30), and the vapor pressure of phenethyl acetate (PEAc) was measured in the entire system . The phase diagram showed complete solubility of the surfactant and t he phenethyl acetate with limited solubilization of water. The water w as dissolved into the surfactant forming a surfactant solution and a l amellar liquid crystal. The vapor pressures of phenethyl acetate measu red in different phases revealed the importance of amphiphilic associa tions for the activity of dissolved phenethyl acetate. This interpreta tion was confirmed by the results from phenethyl acetate solutions in tetraethylene glycol (TEG), in highly pure tetraethylene glycol mono n -dodecyl ether (C-12(EO)4), in toluene, and in decane. The difference in intermolecular interactions between the acetate and the various com pounds are illustrated by the values of the Henry's constants of the a cetate. (C) 1997 Elsevier Science B.V.