PHASE EQUILIBRIA IN MIXTURES OF POLYMERS AND SUPERCRITICAL FLUIDS. EXPERIMENTAL SETUP AND INTRODUCTORY MEASUREMENTS

摘要

An apparatus for measuring high-pressure phase equilibria at temperatures up to 473 K and pressures up to 2000 bar is presented. The applied method of the construction of a phase diagram for a fluid mixture requires the determination of families of P-T diagrams of constant composition (isopleths). The equipment consists of a variable volume view cell, temperature stabilizing system, pressure generation system and a system that make loading of the cell with a gas component possible. The equipment and the experimental procedure were tested by measuring phase equilibria for two mixtures ethylene - eicosane, and carbon dioxide - squalane. Phase equilibria in the system ethylene + linear low molecular weight polyethylene were also studied.