SEDL / STP / STP1249-EB / STP15363S

The Nature of the Glass Transition and its Determination by Thermal Analysis

Wunderlich, B
The University of TennesseeOak Ridge National Laboratory, KnoxvilleOak Ridge, TNTN

Pages: 15    Published: Jan 1994

Download this paper for $25 PDF (300K)          View License Agreement
Abstract

In this paper operational definitions of the glass transition and the pertinent condensed phases are given. This is followed by a description of the basic observations of glass transitions via thermal analysis using calorimetry, dilatometry, as well as theromechanical, dielectric, and dynamic mechanical analysis. The time dependence of the glass transition causes hysteresis phenomena and physical aging. Strain effects on the observation of the glass transition are identified. Complications resulting in symmetric and asymmetric broadening of the glass transition are linked to nanometer and micrometer scale phase separations. Finally, a rigid amorphous phase is identified in some semicrystalline polymers.