Similar dielectric behaviour of polyphenylglycidyl-ether and diglycidyl-ether of bisphenol-A at glass transition temperature

摘要

In this work, the dynamics of the primarya- and the Johari-Goldstein (JG)b- processes are studied with dielectric spectroscopy. We found the relaxations at glass transition temperature in polyphenylglycidyl- ether and diglycidyl ether of bisphenol-Ato be strongly correlatedover a wide temperatureTand pressurePrange.Analysing the temperature and pressure behaviour of thea- and (JG)b-processes, a clear correlation has been found between the structural relaxation time, the Johari-Goldstein relaxation time and the dispersion of the structural relaxation.