Some New Aspects of the Glass Transition in Simple Polymer Melts

Abstract

The general physics of the glass transition remains a subject of intense research. Furthermore, many polymeric materials in practical use are in the glassy state. Glass formers are classified as strong or fragile, meaning that the observed viscosity, as the temperature approaches the glass transition temperature, either follows the Arrhenius law (strong) or the KWW (Kohlrausch-Williams-Watts) law (fragile), with the latter exhibiting a much stronger temperature dependence. The latter is important for many industrial production processes. Polymers are fragile glass formers and prototypical materials for investigating the glass transition. The deviation from the Arrhenius law is called fragility. In this lecture, an adapted model for studying the glass transition of polymer melts will be introduced and applied. Furthermore, a new data-driven method for identifying the first signs of approaching the glass transition during cooling will be discussed.