Polymer Relaxation Time Enhancement at Temperatures above Glass Transition Temperatures Predicted by Idealized Mode-Coupling Theory

Abstract

The mode-coupling theory of glass transition predicts the relaxation time divergence of glass-forming materials at the crossover temperature, which is approximately 1.2 times the calorimetric glass transition temperature. However, this divergence has not been experimentally observed. This is known as the most serious drawback of the mode-coupling theory. The use of viscosity-sensitive single molecule fluorescence probes enables the detection of the poly(vinyl acetate) and poly(ethyl methacrylate) relaxation time enhancement around the crossover temperature, thereby supporting the prediction by the mode-coupling theory.