Dielectric relaxation in eugenol

Abstract

The dielectric behaviour of eugenol has been determined over the temperature range 23.5 to –69°C; this range is similar to that used in a previous investigation of the viscoelastic properties. It is found that all the dielectric relaxation data could be reduced to a single curve which could be fitted by a Davidson–Cole equation with the distribution parameter β_D= 0.6. Above –56°C, the temperature dependence of the dielectric relaxation time, τ_D, is the same as that of the viscosity, and differs from that of the viscoelastic retardation time τ_r. However, the temperature dependence of the resistivity is similiar to that of τ_r. The results are discussed with regard to the differing aspects of molecular motions which are shown by the dielectric and viscoelastic relaxations.