Polymer miscibility in organic solvents and in plasticizers—a two‐dimensional approach

From thermodynamic considerations based on associated solution models and from the Hansen's three‐dimensional solubility parameter concept, it is found that the solvent power of an organic liquid for a given polymer can be characterized by two parameters, δ h and χ H , where δ h is the hydrogen‐bonding solubility parameter of the liquid, and χ H is a term which takes account of the dispersion and polar interactions between the liquid and the polymer and of the effects due to temperature and molecular size of the liquid. It is also found that Hansen's solubility sphere for the polymer can be represented as a solubility circle in the proposed χ H −δ h plane. The proposed approach is applied successfully to polymer–plasticizer systems.