Liquid-Glassy Polymer Interphases: Diffusion Kinetics in Conditions of Unlimited Liquid Supply

Abstract

We investigate evidences of diffusion controlled by mechanical relaxation of the glassy matrix, i.e. Case-II mechanism, in a series of liquid/glassy interphases formed by polystyrene (PS) and poly (phenylene oxide) (PPO) as liquid and glassy components respectively. Diffusion experiments were performed in conditions of unlimited supply of the liquid polymer, parallel to those in which Case-II has been effectively verified. Interphase profiles were obtained via optical sectioning with confocal Raman microspectroscopy. We observed that interphase diffusion kinetics were markedly Fickean, in contrast with interpretations from other authors that invoke Case-II to explain the mechanisms that rule interphase evolution in these systems.