Mm. Coleman et al., EQUILIBRIUM-CONSTANTS AND THE PREDICTION OF MISCIBILITY WINDOWS FOR POLYMER BLENDS CONTAINING POLY(TETRAFLUOROETHYLENE-ALT-VINYL ALCOHOL), Journal of polymer science. Part A, Polymer chemistry, 31(8), 1993, pp. 2039-2056
Theoretical calculations of miscibility windows for binary polymer ble
nds in which one component is an essentially alternating copolymer of
tetrafluoroethylene and vinyl alcohol (FVOH) are reported. FVOH has an
inherently low solubility parameter [almost-equal-to 6.2 (cal. cm-3)0
.5] that is outside the range commonly encountered in miscible polymer
blends and thus represents a stringent test of the predictive capabil
ities of an association model we have used in previous work. The appli
cation of this model requires that we determine dimensionless equilibr
ium constants describing the self-association of a model compound 3,4-
pentafluorobutan-2-ol (PFB) at 25-degrees-C from infrared spectroscopi
c data. Analogous equilibrium constants for FVOH were scaled from thos
e of PFB by taking into account differences in the molar volume of the
model and the specific repeat of the copolymer (see M. M. Coleman, J.
F. Graf, and P. C. Painter: Specific Interactions and the Miscibility
of Polymer Blends, Technomic, Lancaster, PA, 1991). Equilibrium const
ants describing the inter-association of FVOH with ester type carbonyl
groups were obtained from spectroscopic studies of miscible blends wi
th poly (ethyl methacrylate). These equilibrium constant values were t
hen used to calculate theoretical miscibility windows for the complete
range of blends of FVOH with polymethacrylates, ethylene-co-methyl ac
rylate, styrene-co-methyl acrylate, and ethylene-co-vinyl acetate copo
lymers. Experimental results performed in our laboratories confirm the
general validity of the predicted miscibility windows.