Evaluation of epoxy nanocomposites for electrical insulation systems

Epoxy nanocomposites can be used as electrical insulation material in various high voltage applications, due to their improved ductility, fatigue resistance, in combination with enhanced electrical properties, compared to the neat epoxy. In a previous work, the mechanisms leading to these improvements in Al₂O₃ nanoparticles filled epoxy nanocomposites were investigated on lab scale samples (<; 100 ml). It was shown that a homogenous dispersion of the nanoparticles in the matrix was required for achieving such improvements. In the present study, different dispersion techniques were used for preparing Al₂O₃/epoxy nanocomposites on a larger scale (>; 5L). The glass transition temperature of all formulations remained the same as the base resin. The nanocomposite with the best dispersion maintained the dielectric properties, and exhibited a 40 % increase in elongation at break, with improved tensile modulus, thermal conductivity, and AC break down strength (slightly increased mean value and significantly reduced scatter), compared with the base resin.