Dielectric Absorption in Solid Aliphatic Methyl Esters

Abstract

The dielectric absorption in three aliphatic methyl esters, methyl palmitate, methyl stearate, and methyl behenate, has been measured over a wide frequency range at temperatures of 25, 2, and -18 °C. The measurements reveal that there are two absorptions in these esters, both arising from relaxation mechanisms. Deductions made from the results indicate that one of the absorptions is due to the rotation of the ester molecule from one position of equilibrium in the crystal lattice to another, and that the other absorption arises from rotation of the polar group (which in these molecules is at one end) from one position of relative equilibrium to another.