Advances in the generalized entropy theory of glass-formation in polymer melts

作者：Dudowicz Jacek^*; Douglas Jack F; Freed Karl F

来源：Journal of Chemical Physics, 2014, 141(23): 234903.

DOI：10.1063/1.4903842

The generalized entropy theory (GET) of polymeric glass-forming liquids is reformulated into a computationally simpler and more natural formalism than the original version of this theory. The new theoretical framework greatly facilitates establishing essential trends in the dependence of the segmental relaxation time tau, fragility, characteristic temperatures of glass-formation, etc., on the combined influences of monomer molecular structure, chain rigidity, and cohesive interaction strength. Special attention is placed on the estimating the parameters of the phenomenological Vogel-FulcherTammann relations for describing segmental relaxation in diverse liquids in the low temperature range of glass-formation, T-g > T > T-c (or T-g < T < T-g + 100 K), where T-g and T-c are, respectively, the glass transition temperature and the crossover temperature separating the high and low temperature regimes of glass-formation. Finally, we discuss how the molecular energetic interaction parameters of the GET can be estimated from experimental data. Illustrative calculations are performed for the stiffness factor sigma and the cohesive energy density u as a first step in this direction.

• 出版日期2014-12-21