چكيده به لاتين
The purpose of this study is to fabricate a hydrophobic silicone rubber nanocomposite
coating for electrical insulators. For this purpose, two types of Silicone polymer (RTV-2
molding Silicone and pure Sylgard184 Silicone were used. It must be mentioned that RTV-2
Silicone polymer and Sylgard184 Silicone polymer have hydrophobic properties. To increase
the contact angle of these two polymers, Silica and Titanium dioxide nanoparticle were used
to increase the surface roughness and thus reduce the adhesion force between the surface and
water droplets. The hydrophobicity test was performed to determine the static contact angle of
the water droplet with the coating surface. The effects of factors such as inorganic salt
contamination and UV irradiation on the hydrophobic property after exposure to contamination
in the coating were investigated. Finally, by covering the coating on the insulator, a high
voltage electrical failure test of ceramic insulator was carried out under both wet and dry
conditions and in both presence and absence of contamination.
Experiments have shown the better performance of nanocomposite coating containing RTV-
2 Silicone polymer for hydrophobicity under contamination condition as well as recovery of
the hydrophobic property after exposure to contamination compared with Sylgard184 polymer.
The greater surface contact angle, under the absence and presence of the contamination, and
recovery of hydrophobicity, was obtained by adding 50% Titanium dioxide nanoparticle. An
electrical discharge test was also conducted for the insulator covered by the coating, which
showed the increase of the voltage of the electrical failure in comparison with the uncoated
insulators in wet and dry conditions. Exposure to inorganic salt contamination significantly
reduces the surface contact angle, but exposure to ultraviolet radiation does not affect the
hydrophobicity of the nanocomposite coating containing Silicone polymer. Addition of
additives (Silica, Titanium dioxide, ATH, and solvent) to the silicone polymer results in surface
cracks in the nanocomposite coating. The effect of adding ATH due to its hydrophilic structure
reduces the contact angle of the surface and the solvent due to increasing the transfer of
nanoparticles to the coating surface and increasing the surface roughness increases the contact
angle of the coating surface
