Since the discovery of a large electrostrictive effect in
some polyurethane elastomers,1 relatively few advances
have been reported in either the fundamental
understanding of the phenomenon or its practical application.
Furthermore, the number of articles currently
available that deal with the measurement of
polyurethane electrostrictive properties is quite limited.
2–5
Several macroscopic models have been introduced
in an attempt to derive theoretical relations between
electrostrictive coefficients and other macroscopic
properties such as dielectric constants and elastic compliances.
Popular references on this topic include
Anderson,6 who evaluated electrostrictive coefficients
using a model dielectric of linearly polarizable point
dipoles and a Lorentz cavity approach; Katz and Nelson,
7 who developed a model for the susceptibility of
the material, taking into account the orientation of
urethane group dipoles in an electric field; and Shkel
and Klingenberg,8,9 who proposed a new approach