Polymer and Materials Science
Wiley InterScience Backfile Collection 1832-2000
Chemistry and Pharmacology
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
A screening study of the solubility of poly(1,1-difluoroethylene) (PVF2, M̄w = 2 × 105) at room temperature in a wide variety of dipolar aprotic species has facilitated the discovery of a series of new solvents (N-methyloxazolidone, cyclic-substituted ureas) and rationalization of the data in a two-dimensional solubility map involving their dipole moment, μ, and their hydrogenx-bond-accepting (HBA) power β (Taft solvatochromic parameter). This map may be used as a predictive tool for the research of new functional classes of solvents, such as N-substituted mixed amideester of phosphoric acid or N-substituted sulfurous diamides. The variations of the intrinsic viscosity of the polymer with solvent polarity may be quantitatively analyzed using a linear multiparametric correlation which emphasizes the two opposite contributions of cavitation effects (Hildebrand solubility parameter δ) and of polymer-solvent interactions (β) on the coil expansion: [η] (dL.g-1) = 0.792 - 1.2 × 10-3δ2(J.cm-3) + 1.59 β. Finally, 1,3-dimethyl-2-oxo-hexahydropyrimidine (N,N′-dimethylpropylene urea) leads to the highest value of the refractive index increment (dn/dc = -0.065 mL.g-1 at λ = 632 nm), and thus appears as the best solvent for light-scattering measurements.
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