Dielectric Properties of Polyaryletherketone/CaCu3Ti4O12 Nanocomposite Films Fabricated via Cast Film Extrusion Process

Abstract

Polymer composites prove to be the best choice for improving the dielectric properties of polymers. This work mainly focuses on studying the dielectric behavior of polyaryletherketone (PAEK), a high-temperature polymer, and its nanocomposite films with CaCu <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Ti <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">12</sub> (CCTO) ceramics. The dielectric constant of PAEK improves significantly after the addition of CCTO nanoceramics and shows nearly frequency-independent behavior. The dielectric loss of these nanocomposites is low and is in the range of 0.004–0.006 at room temperature and 1 kHz. Dielectric properties exhibit very good temperature stability up to 150 °C. Activation energies calculated from both electric modulus and conductivity analyses show that the movement of charge carriers is responsible for both relaxation and conduction processes. The conductivity mechanism follows the correlated barrier hopping (CBH) model at low temperatures and the nonoverlapping small polaron tunneling (NSPT) model at high temperatures. Breakdown characteristics are analyzed using Weibull probability distribution. These PAEK/CCTO nanocomposites are proposed as potential materials for high-temperature dielectric applications.