Enhanced Electrical Breakdown Strength in Nano-coatings of Polymer Composites

Nano-coatings, which are generally composed of inorganic nanofillers and polymer binders, have attracted increasing interest in electrical industry, because of their unique advantages for improving the dielectric and electrical properties of the electric devices, accompanied by the versatile manufacturing process. Here, a uniform coating layer of aluminum hydroxide (ATH), bound by polymethyl methacrylate (PMMA), was successfully manufactured by dip/spray coating process. It can be found the filler contents show an apparent influence on the DC breakdown strength of the coating materials. Furthermore, to deal with the brittleness of the coating layer, Polyvinyl Butyral (PVB) was adopted as the third component, and, as a result, the DC breakdown strength is also significantly enhanced with an optimized content of PVB. This work shows a feasible route, i.e., compositional tailoring, to modify the electrical properties of the nano-coating materials, which provide opportunities for their wide applications, especially under harsh and extreme working conditions.