An experimental study about the surface behaviour, under electrical stress in contaminated wet conditions, of different nanostructured polymers

A joint research project University of Genova/Politecnico di Torino regards the influence of selected fillers, inserted to obtain different micro and nano-structured compounds of ethylen vynil acetate (EVA) copolymer, on the surface electrical behaviour, in presence of artificial wet contamination (macroscopic tracking). Three polymer composites have been realised, of which two contained fluorohectorite as nanofiller. Fluorohectorite is a layered silicate (clay); when its molecules are organically modified, polymeric macromolecules can set between their layers, enabling the formation of nanoscale range geometries along one dimension, thus increasing dramatically the interface interactions. A mix of fluorohectorite (nanofiller) and trihydrate alumina (THA microfiller) is also considered. Suitable tests were carried out on flat specimens in order to rank the performances of the above materials. The electrical tracking tests outcome indicates different results in the case of EVA with THA and fluorohectorite presenting a better behaviour with respect to the other considered materials.