Post-heat treatment effect on the dielectric response of epoxy samples

In the present experiment, the dielectric response of various types of epoxies was investigated in the frequency and time domain. The samples consisted of nanostructured epoxy microcomposites and reference microcomposites. Water ingression at the fabrication step and/or at measuring time is known to affect the dielectric response of materials such as epoxy. Prior to measurement, some samples were submitted to 160°C during 48 hours under vacuum. Heating the epoxy sample under vacuum was found to have a substantial effect on dielectric properties specially when the microcomposite was nanostructured. In the nanodielectric case, pre-treatment conditions could produce a drop in the dielectric constant, about 5% at around 10^-2 Hz. This observation would be consistent with the removal of the polarisability associated with water molecules.