Table of Contents
International Journal of Microwave Science and Technology
Volume 2012, Article ID 628237, 5 pages
Research Article

The Impact of Blue Inorganic Pigments on the Microwave Electrical Properties of Polymer Composites

1I3N and Physics Department, University of Aveiro, 3810-193 Aveiro, Portugal
2LRP, CNRS, 2 rue Henry Dunand, 94320 Thiais, France

Received 5 October 2011; Accepted 16 January 2012

Academic Editor: Paolo Colantonio

Copyright © 2012 L. C. Costa and F. Henry. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


We present the results of the measurement of complex dielectric permittivity, in the microwave frequency region, on glass reinforced polybutylene terephthalate (PBT) with blue inorganic pigments. The cavity resonant method had been used in order to measure the shift in the resonant frequency of the cavity, caused by the insertion of a sample, which can be related to the real part of the complex permittivity. Also, the quality factor of the cavity decreases with the insertion of a sample. The changes in the inverse of this quality factor give the imaginary part. In order to predict the dielectric behavior of this composite, we had developed a program of numerical simulation to calculate the complex permittivity of the inclusion. By using some of dielectric mixture laws (Maxwell-Wagner-Sillars, Hanai, Looyenga, inverse and direct Wiener, and Bruggemann), we can predict the dielectric behavior of the composite in a large range of volume fraction of inclusions.