Pressure Effects on the Dynamic Heterogeneity of Miscible Poly(vinyl acetate)/Poly(ethylene oxide) Blends
journal contributionposted on 14.08.2012, 00:00 by George Zardalidis, George Floudas
The poly(vinyl acetate) (PVAc) segmental dynamics is studied as a function of composition, temperature, and pressure in thermodynamically miscible blends with poly(ethylene oxide) (PEO) by dielectric spectroscopy. In the PVAc-rich blends all short-range correlations are dominated by the PVAc component. An invariant frequency dispersion is found when the spectra at each blend composition are compared under isochronal conditions. The self-concentration model with a fixed PVAc self-concentration of ∼0.22 qualitatively describes the temperature dependence of the PVAc segmental dynamics both at atmospheric and at elevated pressures.