Assessment of hydrophobicity of silicone and fiber reinforced filled epoxy composites under contamination

This paper discusses the effect of different contaminants on the contact angle of silicone and glass reinforced epoxy composites. Using a combination of fillers consisting of silica, alumina, alumina trihydrate, magnesium oxide and calcium carbonate, the surface wetting characteristics of three different epoxy composites is investigated in this work. The contact angle of the materials is studied with different contaminants individually applied and with the application of AC or DC stress. Surface energy parameters are estimated to account for the variations in the contact angle. The effect of dry heat on the contact angle is also investigated. The study shows that silicone rubber retains its hydrophobicity with different contaminants except for sea water under electrical stress. In case of the epoxy composites, the fillers help to enhance the contact angle and impart different surface wetting properties under contamination with the application of electrical stress.