Speed of Sound, Density, and Derivative Properties of Fatty Acid Methyl and Ethyl Esters under High Pressure: Methyl Caprate and Ethyl Caprate

The speed of sound in methyl caprate (C 11 H 22 O 2 ) and ethyl caprate (C 12 H 24 O 2 ) was measured using a pulse echo technique operating at 3 MHz. The measurements were carried out at pressures up to 210 MPa in the temperature range (283.15 to 403.15) K. Additional density measurements were performed up to 100 MPa from (293 to 393) K. From these measurements, the density was evaluated up to 210 MPa, and the isentropic and isothermal compressibilities were determined in the same P – T domain.