Influence of the Component's Glass Transition Temperature in Miscible Polymer Blends on α Internal Friction Peak

The dynamic mechanical studies for two miscible polymer systems PEO/PMMA and SAN/PMMA showed that, just as expected, the glass transition temperature T g values, the height of α internal friction peak, and the temperature dependence of relaxation time of all the blends were between the neat components, and had a strong component dependence. In particular, it was observed that the α relaxation of PEO/PMMA blends was far broader than that found for the neat components, however, this phenomena was not found for SAN/PMMA blends. The difference between T g of the blend components seemed to be the relevant feature giving rise to the anomalous broadening of polymer blend dynamics in the α relaxation range, if we assumed that the fluctuations of concentration could give rise, through the T g dependence on composition, to a distribution of relaxation processes.