Comparison of the transverse viscoelastic properties of benzyl benzoate from ultrasonic and light-scattering measurements

The results obtained from depolarised light scattering experiments as a function of temperature are compared with ultrasonic impedance measurements previously obtained by Barlow and Erginsav. At low temperatures (in the supercooled region) a depolarised propagating doublet is observed and the velocity thus obtained is concordant with Barlow's results. At higher temperatures the relaxation time, τ_C, is obtained from the width of the depolarised spectrum. Contrary to the suggestion of Barlow, there is little correspondence between τ_C and the retardation time for viscous response.