Measurement of the Glass-Transition Temperature of Simple Liquids

The glass-transition temperatures of 34 liquids have been measured by differential thermal analysis, and the results compared with the values predicted from viscosity measurements by the equation lnη = A″+B″/(T—T0). In those liquids which have two non-Arrhenius viscosity regions, there is good agreement between observed Tg values and those predicted from the lower-temperature form of this equation. In those liquids which have only one observable non-Arrhenius region, measured Tg values are usually lower than those predicted from viscosity measurements. It is suggested that this is caused by a change in non-Arrhenius viscosity behavior at higher viscosities which are unattainable experimentally.