Dilute solutions of poly(vinyl alcohol) derived from vinyl trifluoroacetate

Abstract

AbstractThe dilute‐solution behavior of poly(vinyl alcohol) (PVAVTFA), derived from vinyl trifluoroacetate, in water‐dimethylsulfoxide (DMSO) mixtures was investigated. With solvent mixtures ranging from 10 to 20 vol % DMSO, the relation between the reduced viscosity ηsp/C and the polymer concentration C was linear for polymer concentrations above 0.2 g/dL, whereas in solutions in mixed solvents of other compositions the dependence was linear for polymer concentrations above 0.1 g/dL. The relation between the intrinsic viscosity [η] obtained for aqueous solutions of PVAVTFA and the molecular weight M estimated from viscosity measurements in solutions of poly(vinyl acetate) (PVAVTFA), obtained by acetylation of PVAVTFA, was given by [η] = 7.34 × 10−4 M0.63. The value of [η] was greatest for the solvent mixture with 10 vol % DMSO and smallest for about 50 vol % DMSO, and Huggins constants k were smallest and greatest for these two cases, respectively. The turbidity of the solutions of low‐molecular‐weight PVAVTFA, was higher than that of high‐molecular‐weight PVAVTFA up to 30 vol % DMSO, and the reverse relation held for 40‐70 vol % DMSO.