John N. Argyropoulos

Determination of phase boundaries from pressure-volume data for polymer-solvent-carbon dioxide mixtures

Abstract In the past, experimental determination of phase transitions (bubble points and cloud points) of polymer-solvent-supercritical-fluid systems have been made by direct visual or optical observations. Although much data has been measured, this procedure can not be used in systems that contain pigments or systems that are inherently cloudy. Furthermore, this method has the inherent limitation of being subjective. In this work, we demonstrate a method of resolving volumetric data to determine phase transitions. The method can be used for solutions which are opaque (such as pigmented paint formulations) and for determination of multiple phase transitions occurring at constant temperature.