STRUCTURE OF TRANSPARENT WATER AND OIL DISPERSIONS STABILIZED BY POLYMERIC EMULSIFIERS

An investigation has been made of transparent oil-water dispersions stabilized by amphiphilic polymeric substances. The samples are well-defined polyethylene oxide - polystyrene graft copolymers with various lengths of backbone and side chains. The domain for existence of microemulsions and the phase diagrams were determined turbidimetrically by titration with 2-propanol for water/toluene/graft copolymer systems. Results are generalized to several amphilic copolymers of different chemical structure using various polar oils. A behavior markedly different is observed depending on whether soaps or copolymers are used for these systems. In particular, polymeric microemulsions form only when there is a mutual solubility for the ternary solvent mixture. A simple model is proposed, based on particles which consist of two concentric spheres having a PS part solvated by toluene and a PEO part by water, the continuous medium being composed of the ternary solvent mixture at mutual solubility. The size of the particles was determined by light scattering spectroscopy. © 1979 Dr. Dietrich Steinkopff Verlag.