Possible mechanism of superior partial-discharge resistance of polyamide nanocomposites

The dielectric properties of polyamide nanocomposites were examined, focusing especially on their resistance against partial discharges. The paper compares the surface roughness caused by partial discharges and that caused by exposure to plasmas, between polyamide with and without inorganic nanofillers. From X-ray diffraction spectroscopy, it was confirmed that the nanofillers are rearranged in parallel with their surfaces with a mutual distance around 1 nm after the nanocomposite was subjected to partial discharges. Such ordered arrangement of nanofillers should contribute to the high durability against partial discharges in polyamide nanocomposites, in addition to the effects of the presence of mica, high crystallinity, and strong ionic interaction at mica/resin interfaces. Furthermore, the result of a preliminary attempt to detect the structural change through observation of photoluminescence spectra is also reported.