Nanomechanical characterization of nanocomposite polymers for electrical engineering

Polymer nanocomposites have recently been pointed out to upgrade the organic matrix properties for electrical applications from energy storage to power delivery. By adding a small amount of nanofillers, the electrical, thermal and mechanical properties such as breakdown strength, treeing, Young modulus or lifetime could be greatly modified. This properties change is certainly attributed to nanofillers nature and size, but also to the specific area between the polymer host and nanoparticles, known as the interphase area. In this work, the studied nanocomposite is made of a polyimide (PI) matrix and hexagonal-boron nitride (h-BN) nanofillers. Previous studies on this nanocomposite were held to observe its macroscopic properties change. The aim of the present work is to complete previous results by performing a local mechanical characterization. Thus, the peak force quantitative nanomechanical (PF-QNM) mode of atomic force microscopy (AFM) is used. Results show that there is a correlation between local and macroscopic properties for this nanocomposite material.