Space charge dynamics in polyimide based nanocomposites

Polymer nanocomposites have attracted wide interest as a method of enhancing polymer properties and extending their applications. In polymer nanocomposites, chemically dissimilar components are combined at the nanometer scale, and stronger interactions between the polymer and nanoparticles produce markedly improved materials with better electrical, mechanical, thermal, and rheological performances than the conventional filled polymer composites. In recent years, polymer nanocomposites have been extensively studied in optical, thermal and mechanical properties, but there has been relatively little research into dielectric properties. Polyimide is an excellent dielectric material that has a wide range of applications at elevated temperatures. In this paper, space charge in polyimide based nanocomposites has been measured under high dc electric fields using the pulsed electroacoustic technique. Different types and levels of nanoparticles have been studied to understand the interaction between nanoparticles and polyimide matrix. Charge dynamics during “volts on” and “volts off” have shown that the addition of nanoparticles has a significant influence on charge formation and decay processes.