INTERACTION STRENGTH, NONRANDOM MIXING, AND THE COMPOSITIONAL VARIATION OF GLASS-TRANSITION TEMPERATURES

Through the quasi-chemical approximation, I consider the effect of interaction strength and nonrandom mixing on the compositional variation of glass transition temperatures, T(g). Enthalpic relations are derived, and the reduction of these to a random-mixing relation is considered. Previous empirical random-mixing equations are shown to be approximations to this. This treatment is complemented by a volume-based theory. Conditions for the consistency of these two treatments are given.