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

In this work, the dynamics of the primary and the Johari-Goldstein (JG) processes are studied with dielectric spectroscopy. We found the relaxations at glass transition temperature in polyphenylglycidylether and diglycidyl ether of bisphenol-A to be strongly correlated over a wide temperature T and pressure P range. Analysing the temperature and pressure behaviour of the and (JG) -processes, a clear correlation has been found between the structural relaxation time, the Johari-Goldstein relaxation time and the dispersion of the structural relaxation.