Structural Aspects Of The Rheology Of Glass Forming Melts

In the framework of the Absolute Rate Theory a relation is derived connecting the molar and the viscous volume of a liquid with the activation energy for self diffusion. It is found that the smaller the molar volume the higher is the critical stress at which a deviation from Newton's law is observed. The validity of these relations is tested by using data for a number of silicate glass forming systems and organic polymer melts.