Arrhenius-like Temperature Dependence of the Segmental Relaxation below Tg

Published

October 12, 2021

Author(s)

P A. O'Connell, G B. McKenna

Abstract

In a recent paper DiMarzio and Yang [J. Res. Natl. Inst. Stds. Technol., 102, 135 (1997)] predicted that transport properties such as viscosity and diffusion coefficient do not follow the typical WLF- or Vogel-Fulcher-type of temperature dependence as the glass transition is approached. Rather, a transition to an Arrhenius-type of temperature dependence is predicted. Here we describe long term aging experiments that explore the temperature dependence of the viscoelastic response of polycarbonate in the vicinity of the glass transition. Aging the material for long times below the nominal glass transition temperature, assures that equilibrium is attained and we can directly test the DiMarzio-Yang prediction. In tests in which glassy samples of polycarbonate were aged into equilibrium at temperatures up to 17 EC below the conventionally measured glass transition temperature, we find that the results are consistent with a transition from Vogel-Fulcher- or WLF-type behavior to Arrhenius-like behavior. Our results are discussed within the context of other measurements on non-polymeric glasses and other recent results on polymeric glass formers.

Citation

Journal of Chemical Physics

Pub Type

Journals

Keywords

glass, glass transition, polycarbonate, polymer, segmental relaxation, viscosity, Vogel-Fulcher, WLF

Citation

O'Connell, P. and McKenna, G. (2021), Arrhenius-like Temperature Dependence of the Segmental Relaxation below T_g, Journal of Chemical Physics (Accessed October 31, 2024)