TITLE:
Dielectric spectroscopy of diglycidyl ether of bisphenol-A at glass transition temperature
AUTHORS:
Soheil Sharifi
KEYWORDS:
Dielectric Relaxation; Nano-Size Motion; Secondary Relaxation; Pressure and Temperature
JOURNAL NAME:
Natural Science,
Vol.4 No.2,
February
22,
2012
ABSTRACT: We used broadband dielectric spectroscopy in the frequency range from 10–2 Hz up to 107 Hz and we found dynamics of the primary α- and intermolecular Johari-Goldstein (JG) β-processes are strongly correlated in diglycidyl ether of bisphenol-A over a wide temperature from 193 to 283K and pressure P range from 0.1 to 600 MPa. Analysing the temperature and pressure behavior of the α - and (JG) β-processes, a clear correlation has been found between the structural relaxation time, the Johari-Goldstein relaxation time and the dispersion of the structural relaxation. These results support the idea that the Johari-Goldstein relaxation acts as a precursor of the structural relaxation and therefore of the glass transition phenomenon.