Development of cooperativity in the local segmental dynamics of poly(vinylacetate): synergy of thermodynamics and intermolecular coupling

The properties of the α- and Johari–Goldstein β-relaxations in conjunction with configurational entropy data are used to show how cooperativity of the dynamics of poly(vinylacetate) develops as temperature is decreased towards Tg from above. Such behavior is also characteristic of small molecule glass-forming liquids, demonstrating that the combined effects of configurational entropy changes and intermolecular coupling underlie structural relaxation phenomena. Any theoretical model must include both thermodynamics and many-body dynamics in order to accurately describe the general properties of the glass transition.