Properties of PVDF Polymer for Sonar

Abstract

Polyvinylidene fluoride (PVDF) polymer is evaluated for application in large sonar arrays. The piezoelectric coefficients and elastic constants of thick (550 urn) PVDF produced at Raytheon are measured, and the apparatus for making the measurements is described. It is shown, both theoretically and experimentally, that electrodes deposited on the surface can stiffen the polymer and significantly alter the observed properties. The free-f ield frequency response for an experimental hydrophone is shown over a broad frequency range, f ee of spurious resonances. Stability to relatively high temperature (90°C) and to high static pressure (6.9 MPa = 1000 ps 1 are shown from experimental data.