Abstract
Measurements of relaxation time in epoxy resin [poly(bisphenol -co-epichlorohydrin), glycidyl end capped] in the supercooled liquid state have been carried out using dielectric spectroscopy over the frequency range from 10 mHz to 10 MHz as a function of pressure (up to ) and as a function of temperature. To our knowledge, this is the first time a two-dimensional surface of relaxation times in epoxy resin has been plotted. The pressure and the temperature dependence of structural relaxation times are in good agreement with the extended Vogel-Fulcher-Tammann equation. For isobaric data, the fragility of the epoxy system reveals a tendency to decrease at elevated pressures. By using pressure as an additional variable, the influence of pressure on glass transition temperature has been determined.
- Received 20 February 1997
DOI:https://doi.org/10.1103/PhysRevE.56.5764
©1997 American Physical Society