Clouding behaviour of an ethylene oxide propylene oxide block copolymer

Cloud point (CP) studies on aqueous solutions of several ethyleneoxide-propyleneoxide block copolymers and their mixtures in an aqueous solution show some interesting features. While single copolymers yield a phase behaviour similar to conventional ethyleneoxide based non-ionic surfactants, their mixtures show marked deviations from ideality. One copolymer shows double cloud points over a certain concentration range. Ionic surfactants show a marked increase in the CP of block copolymer solutions, the CP increasing effect is more distinct for anionic surfactants. Increasing the nonpolar chain of the surfactant favors the increase in the cloud point.