Vapor–liquid equilibrium of copolymer + solvent mixtures: Thermodynamic modeling by two theoretical equations of state

Abstract

Copolymers are increasing their importance from the commercial point of view, mainly due to their tuned physical properties for specific applications in the polymer manufacturing. Copolymers allow tailoring new materials with desirable features by blending specific copolymers, which contribute for the physical properties of the final material. The description of the fluid-phase equilibrium of copolymer + solvent mixtures by thermodynamic models is essential for the design of new manufacture processes. In this work, vapor–liquid equilibrium data for several copolymer + solvent mixtures were modeled using two theoretical equations of state: one based on the lattice gas theory (LGT) and another one based on the statistical association fluid theory, called perturbed chain-SAFT (PC-SAFT). The results show that the PC-SAFT equation of state provides a better representation of the experimental data in terms of pressure deviations.