Abstract
Poly(vinyl acetate)/poly(methyl glycidyl ether) (PVAc/PMGE) blends were found to be miscible in wide ranges of temperature and composition. We made dielectric relaxation measurements for this miscible blend at several compositions to examine the degree of dynamic heterogeneity. Two α-relaxation peaks were observed in both temperature and frequency dependencies of dielectric loss curves. These two relaxation modes were attributed to the segmental motion of each component. From the temperature dependence of each segmental relaxation time, we determined two effective glass transition temperatures (TgeffPVAc and TgeffPMGE) as functions of the blend composition. Existence of the intrinsic Tgeff of the components, which were different more than 20K, indicates that the PVAc/PMGE blend is ‘dynamically heterogeneous’. We found that the self-concentration model could semiquantitatively explain the composition dependence of each Tgeff.
