The cloud-point temperatures ${(T}_{\mathrm{cl}}’\mathrm{s})$ of both binary poly(ethylene oxide) (PEO)–poly(ethylene oxide-b-dimethylsiloxane) [P(EO-b-DMS)] and ternary[toluene/PEO/P(EO-b-DMS)] systems were determined by light scattering measurements at atmospheric pressure. The phase separation behavior upon cooling in the ternary system has been investigated at atmospheric pressure and under high pressure and compared to the phase behavior in the binary system. The phase transition temperatures have been obtained for all of the samples. As a result, the pressure induces compatibility in the binary mixtures, but for the ternary system, pressure not only can induce mixing but also can induce phase separation.

• Received 8 January 2003

DOI:https://doi.org/10.1103/PhysRevB.68.054110