Overlapping Dielectric Dispersions in Toluene

Evidence is presented for the existence of two overlapping dispersions at 20°C in toluene. Resolution of the two dispersions was in terms of separate Debye relaxation processes, with dispersion parameters ε01=2.384, ε∞1=2.269, and τ1=5.80×10−12 sec for the low-frequency process and ε02=2.269, ε∞2=2.222, and τ2=2.0×10−13 sec for the high-frequency process. It is pointed out that it is not precluded that the high-frequency process may in actuality be a resonance absorption. The dielectric constant and loss values were obtained by a free-space method and the results for toluene at 20°C are given for a wavelength range between 9.2 and 2.5 mm. In addition, dielectric constant and loss values for toluene at temperatures of 30°, 40°, and 50°C are reported for wavelengths between 9.2 and 4.0 mm.