ABSTRACT
ABSTRACT: In this chapter, the challenging issues related to the production of porous polymers are reviewed in an effort to pinpoint at the requirements that should be met by prospect thermodynamic models to be used for describing and, ultimately, designing such processes. The role of external conditions of temperature, pressure, and composition of solvent or antisolvent is first discussed and the polymer-foaming processes are categorized accordingly. The role of the glassy state or the (semi)crystalline state for stabilizing the final porous polymer structure is also discussed. It becomes clear that an appropriate model for handling such systems and processes should be applicable to gases, vapors, liquids, or glasses; to low molecular weight solvents as well as to high polymers; to homogeneous as well as to heterogeneous systems and should handle vapor-liquid, liquid-liquid, solid-liquid, glass-to-rubber transitions, and interfacial properties. The nonrandom with hydrogen bonding (NRHB) equationof-state model is such a model, and its essential working formalism is reviewed and applied to a variety of systems and thermodynamic properties including systems of polymers and pharmaceuticals. The very same model is finally applied for describing and providing with designing elements of the polymer foaming process with supercritical fluids.
