On the estimation of the Kauzmann temperature from relaxation data

Abstract

The well known WLF equation describing the relaxation behaviour of glass-forming liquids near the glass transition temperature has been rederived on the basis of Adam and Gibbs' excess entropy model, making use of a novel expression for the entropy of undercooled liquids. It has been shown that C2 in the WLF equation is a nearly constant fraction of (Ts - T2), where Ts and T2 are the reference and the Kauzmann temperatures, respectively. It is demonstrated that the values of T2 obtained from the relaxation data agree well with those calculated from thermodynamic data. The arguments used provide an explanation for the universality of the WLF constant, C2. © 1987.