Supercritical Fluids

The factors that influence high-pressure miscibility and phase separation of polymers in near- and supercritical fluids are reviewed. These are discussed with an emphasis on their significance in a number of applications including but not limited to polymer formation, modifications, processing, and recycling. Methodologies associated with kinetics of phase separation are discussed. Pressure-induced phase separation (PIPS), its dependence on quench depth, and the consequences of penetration into the metastable (nucleation and growth) or unstable (spinodal decomposition) regions are presented. The examples are drawn primarily from research conducted at the University of Maine.