Etude physico-chimique de la solubilite de la polyvinylpyrrolidone et d'autres polybases de lewis,dans des melanges binaires de solvants polaires

We have measured the solubility of polyvinylpyrrolidone and some other polar polymers in organic mixtures composed of halogenated solvents and proton donors such as alcohols or carboxylic acids. As a general rule, a coacervation zone appears which is limited by a closed curve. This property is explained by a selective adsorption of the donor compound by the polymer, leading to a macromolecular complex via hydrogen bonds. This phenomenon is particularly marked when both solvents are near demixing conditions.