Dielectric Relaxation in Biocomposites Based on Olive Pomace Grains

A polyester polymer matrix filled with olive-pomace grains was investigated using impedance spectroscopy in the frequency range 100 Hz to 1 MHz and temperatures from 300 to 360 K. Two relaxations processes were identified. One could be attributed to the α relaxation associated with the glass transition and observed in the neat matrix, while the second was attributed to the accumulation of charges at the pomace grains/polyester interfaces. The relaxation parameters were evaluated from isothermal dielectric spectra by applying the empirical Havriliak-Negami function.