LIQUID-LIQUID PHASE SEPARATION IN MULTICOMPONENT POLYMER SOLUTIONS .7. RELATIONS FOR SPINODAL AND CRITICAL LOCI

The generalization of the Flory-Huggins model to polydisperse systems with an interaction parameter dependent on over-all polymer concentration, treated in previous papers of the series, is explored further regarding spinodal and critical loci. It is proved mathematically that for this model the critical point is located on the right-hand branch of the cloud-point curve, and this is confirmed experimentally for n-hexane-polyethylene. A simple transformation of the equations governing the spinodal and critical loci leads to easier visualization of these loci in terms of certain mappings in the concentration-temperature plane. © 1969, American Chemical Society. All rights reserved.