Investigation of some phenomena on Polymer-based composite

Abstract

The present work is a study of the electrical properties of a ferroelectric-polymer composite. The polymer used is nylon-11, while the ferroelectric material used is barium titanate in the powder form.

The nylon-11/BaTi03 composite films are initially prepared by melting nylon-!! pellets at a temperature of 218±2 C then the filler material is added and the mixture is stirred at the same temperature for 2 minutes. The mixture is sandwiched between two aluminum foils and pressed in a hot press for one minute at a temperature of 210±2 C to obtain a film of a polymer-ferroelectric composite. The films are then left to cool slowly at room temperature. The samples are coated with a silver conductive paint in the opposite major faces with an area of about 0.28 em2.

The electrical properties of these composites are studied by measunng the d.c.conductivity, thennally stimulated polarization current, current creep, voltage-current characteristic and DSC thermograms.

The dependence of current density J on the electric field E at two different temperatures (I05 C and 160 C). From these dependences we deduce some fitting parameters and the separation distance between filler particles. It is found that as the BaTi03 content increases up to 20 wt.%, the separation between filler particles distance slightly decreased leading to an increase in the value of the d.c.conductivity.