Pressure Dependence of Sound Propagation in the Primary Alcohols

Abstract

Measurements of sound absorption and velocity were made on the ethyl, methyl, n‐propyl, and n‐butyl alcohols up to a pressure of 2000 kg/cm2. The results showed that both the shear and compressional viscosities of these liquids increased as the pressure increased, the pressure dependence of the compressional viscosity being the smaller of the two. Measurements of the temperature dependence of the absorption in n‐butyl alcohol at 2000 kg/cm2 showed that no detectable difference in the activation energies for the two viscous processes was caused by the high pressure. It was found that the two‐state structural relaxation theory proposed by Hall to explain sound absorption in water is inadequate to explain the pressure dependence of sound absorption of the alcohols.