Poly(ethylene oxide) Dynamics in Blends with Poly(vinyl acetate)

$^{2}$H NMR relaxation measurements were performed to study the segmental dynamics of perdeuteropoly(ethylene oxide) (d$_{4}$PEO) in miscible blends with poly(vinyl acetate) (PVAc). For two compositions (2{\%} and 50{\%} d$_{4}$PEO), spin-lattice relaxation times were measured in a temperature range well above T$_{g}$. Over the temperature range studied, the segmental dynamics of the PEO component in 2{\%} PEO/PVAc blend is almost the same as that in 3{\%} PEO/PMMA blend reported by Lutz et al. (\textit{Macromolecules 2003, 36, 1724-1730}), even though the T$_{g}$ of PVAc is 100K lower than that of PMMA. In the 2{\%} d$_{4}$PEO blend, the segmental dynamics of PEO is 9 orders of magnitude faster than PVAc segmental dynamics at the blend T$_{g}$. For the two compositions studied, segmental dynamics of the PEO component can be well described by L-M model with a self-concentration of 0.3. By comparing the segmental correlation times of the PEO component with viscoelastic shift factors reported by Urakawa et al. (\textit{J. Non-Crystalline Solids 352, 2006 5042-5049}), it is found that the temperature dependence of the segmental dynamics of the PEO component is weaker than the temperature dependence of the PEO terminal dynamics.