Thermal and dielectric behavior of ternary composites Carbon nanotubes/Graphite/Polyester

Abstract

This study focuses on the development of ternary composites based on polyester matrix reinforced with graphite (Gt) and carbon nanotube (CNT) particles. The structural characterization was performed using small-angle neutron scattering (SANS), infrared (IR), and Raman spectroscopies, providing information about the dispersion of CNT and Gt particles within the matrix. The electrical and dielectric measurements were carried out in a frequency range from 100 Hz to 1 MHz and temperatures from 200 to 400 K. It is observed that, with the addition of CNT, a positive temperature coefficient in resistivity phenomena (PTCR) is identified for the temperatures below the glass transition. The mechanism responsible for this behavior is attributed to the tunneling effect conduction. The dielectric response was analyzed using the complex impedance formalism.