Temperature dependence of the interaction between n‐heptane, carbon tetrachloride, and benzene and poly(vinyl methyl ether) between 120 and 180°C

Abstract

SynopsisThe corresponding-states theory of Flory has been used to characterize the interaction between three different probes, n-heptane, carbon tetrachloride, and benzene, with poly (vinyl methyl ether). Different results are obtained if the characteristic parameters are corrected for their temperature dependences, which are compared for the three different probes. It turns out that the variation with temperature of the interaction energy parameter X l z is also different when using temperaturedependent or temperature-independent reduction parameters. The interaction is weak and very sensitive to small deviations from ideality in the corresponding-states theory. These results suggest that a weakening of polymer-polymer interactions, and not free volume differences, is responsible for the phase separation in polystyrene/poly (vinyl methyl ether) blends.

Phase Separation in Polystyrene−Poly(vinyl methyl ether) Blends Dilated with Compressed Carbon Dioxide

“…PS/PVME blends exhibit a charge-transfer interaction (π-hydrogen bond) between the electron-deficient methoxy proton in PVME and π-orbital in the aromatic ring of PS . Riedl and Prud'Homme are among those that argue that a weakening of this interaction with increasing temperature is responsible for phase separation . They used inverse gas chromatography to measure the interaction parameters between PVME and probes including benzene, which is a model for styrene.…”

“…24 Riedl and Prud'Homme are among those that argue that a weakening of this interaction with increasing temperature is responsible for phase separation. 25 They used inverse gas chromatography to measure the interaction parameters between PVME and probes including benzene, which is a model for styrene. The interaction parameter was then partitioned into enthalpic and entropic contributions using a Flory-Patterson corresponding states approach with characteristic parameters that are corrected for thermal drift.…”