Dielectric behaviour versus temperature of a monoepoxide

The conductivity and dielectric relaxation behaviour of a glass-forming monoepoxide, cresyl glycidyl ether (CGE), were studied from to by impedance spectroscopy, in the temperature interval 83 - 333 K. Data analysis indicated the existence of a transition temperature marking the separation between two different relaxation regimes, in accordance with previous results given by Stickel and co-workers. The temperature is well above the glass transition temperature , and coincides with the temperature at which the timescales of the main and secondary relaxation processes coincide, so at there is a unique overall relaxation process. The splitting layout of CGE differs from that of the very common diepoxide diglycidyl ether of bisphenol-A (DGEBA), studied previously, and also the relaxation at high temperature has a correspondingly different dynamical behaviour. The relaxation strength behaviour is also analysed and compared with that of DGEBA; the similarities are discussed.