Analysis of temperature-frequency dependences of specific conductivity and dielectric permittivity of eugenol

Abstract

Eugenol is a natural multifunctional aromatic compound. The results of the study of the frequency-temperature dependences of the specific electrical conductivity σ, the real ε′ and the imaginary ε" permittivity of eugenol in the range frequencies from 6.28X10^-2 to 6.28X10^7 rad s⁻¹ and temperatures from 153 to 373 K were presented. A structural phase transitions were detected at 213 K and 253 K according to the dependences ε′(T⁻¹) and σ(T⁻¹). A methodological approach for determining the activation energy of relaxators (individual charges or systems of charges in the structure of matter) has been proposed. Five types of relaxation processes in different temperature ranges was revealed. Molecules of eugenol, π-electrons of the benzene ring and those of the double bond of propane chain, the methoxyl and phenolic hydroxyl groups in the liquid and solid phase are relaxators. Their activation energies were 0.0015, 0.32, 0.22, 0.82 and 0.81 eV, respectively.