A nanocomposite material suitable for electrical insulation includes a polymer compounded with a substantially homogeneously distributed functionalized nanoparticle filler. The nanocomposite material is produced by compounding the polymer with the functionalized nanoparticle filler by imparting a shear force to a mixture of the polymer and filler capable of preventing agglomeration of the filler whereby the filler is substantially homogeneously distributed in the nanocomposite material. The electrical insulation may be adapted for AC or DC high voltage, and may also be adapted for low or medium voltage to prevent formation of water tree structures.