Application of ADAM-GIBBS' theory to thermodynamic recovery and structural relaxation.

The Vogel-Fulcher equation, ln tau proportional to H/R(T-T (2)), and the WLF equation, ln tau proportional to -C(1)(T- T(0)/[C(2)+(T-T(0)], can be expressed in the same form. They are known to fit well with relaxation data of liquids in equilibrium. Doolittle's free volume equation, ln tau proportional to l/integral, and Adam-Gibb's entropy equation, ln tau proportional to C/RTS, can be reduced to the Vogel-Fulcher equation with reasonable assumptions on the temperature dependence of the free volume fraction. integral, and/or the configurational entropy, S. However, in predicting the relaxation behavior in the nonequilibrium state, the Adam-Gibbs equation can be shown to be a clearly better theory than the Doolittle equation. Moreover, with the Adam-Gibbs equation, it is shown that the kinetic parameters required to describe physical aging are the same as those necessary to describe dielectric relaxation behavior.