Aging of the secondary relaxation to probe structural relaxation in the glassy state.

The importance of glass formation and the glass transition is linked to their universality, embracing many classes of materials: metallic, inorganic, and organic. There is no agreement on what drives this phenomenon; moreover, experiments are challenging due to the nonequilibrium nature of the glassy state. We present a new approach that provides information about the very slow structural relaxation in the glassy state and reveals the important role of the secondary relaxation. Structural (alpha) relaxation times for glassy polyvinylethylene were determined from changes in the properties of the secondary process during physical aging. These alpha-relaxation times exceed 3 years, making them inaccessible via direct measurement.