Critical Lines and Phase Equilibria in Polymer Mixture Solutions

Authors: Mustafa GENÇASLAN, Mustafa KESKİN

Abstract: The study of phase equilibria is historically one the most important sources of information about the nature of intermolecular forces in non-electrolyte liquids and their mixtures. Phase equilibria have also played an important role for the process development in the chemical industry in the last decades. In this paper, critical lines and the phase equilibria of polymer mixture solutions are investigated for various combinations of the chain length parameters. The model used, which was introduced by Gençaslan et al., combines the lattice gas model of Schouten, ten Seldam and Trappeniers with the Flory- Huggins theory. Critical lines are displayed in the density-density, P,T-and T,x-planes for the "right corner" and "left corner" cases. The crossing point, a point at which two critical lines meet and exchange branches, is also calculated analytically. The P,T-diagrams are discussed according to Scott and van Konynenburg phase diagram classifications.

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