Ternary polymer blends as model surfactant systems

An investigation of the ternary phase prism for low molecular weight poly(e thylene oxide), squalane, and poly(ethylene oxide-b-ethylenepropylene) is p resented. Comparisons are made between this ternary polymer system and clas sic water/oil/surfactant mixtures to establish further a universal phase di agram description for amphiphilic systems. A combination of visual isotherm al measurements, small-angle X-ray scattering, small-angle neutron scatteri ng, and dynamical mechanical spectrometry was used to characterize phases a nd determine phase boundaries. A rich phase diagram was revealed, including most of the equilibrium liquid crystalline phases associated with diblock copolymers, regions of two-phase and three-phase coexistence, and a biconti nuous microemulsion. Differences between this polymer phase diagram and tho se from water/oil/surfactant systems highlight the strong effect of water i n the latter.