Solvation of polymers as mutual association. II. Basic thermodynamic properties

Area of Science:

• Polymer Science
• Physical Chemistry
• Thermodynamics

Background:

• Understanding polymer solvation is crucial for predicting solution behavior.
• Previous models focused on hierarchical association, differing from direct polymer solvation.
• Solvation influences thermodynamic properties and phase diagrams.

Purpose of the Study:

• To explore thermodynamic properties of polymer B solvated by solvent A.
• To analyze equilibrium concentrations, mass distribution, and solvation extent.
• To investigate phase stability, critical temperatures, and closed-loop phase diagrams.

Main Methods:

• Utilizing the theory of equilibrium solvation developed in Paper I.
• Analyzing essential trends in basic thermodynamic properties.
• Comparing solvated polymer solutions with hierarchical association and self-associating solvent systems.

Main Results:

• Equilibrium concentrations, mass distribution, and solvation extent were explored.
• Solvation transition lines, specific heat, and osmotic second virial coefficient were analyzed.
• Closed-loop phase diagrams arise from competing associative and van der Waals interactions.

Conclusions:

• The theory provides insights into solvated polymer solution thermodynamics.
• Competition between interactions leads to closed-loop phase diagrams.
• Generalization is needed for multiple solvent molecule association for quantitative treatment.