Relation entre la solvatation preferentielle et la densite en segments de polymeres: Generalisations et limitations

This paper presents results on viscosity and preferential solvation for the ternary systems: polystyrene (PS)-carbon tetrachloride-methanol, PS-benzene-cyclohexane, PS-chloroform-ethanol and poly(2 vinylpyridine)-ethanol-cyclohexane using linear and branched polymers. For a given ternary system the representation Δλ′ (variation of the preferential solvation coefficient) as a function of Δρ (variation of the segment density) already proposed gives a unique curve. This shows that this relation is not sensitive to branching or to molecular weight of the polymer when the dimensions of the polymer in the mixed solvent are lower than in the pure good solvent. However, when the dimensions of the polymer in the mixed solvent are higher than in the pure good solvent, the relation between Δλ′ and Δρ cannot be applied.