Conference Paper

Loss and recovery of hydrophobicity of RTV silicone rubber coating

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Abstract

The loss of surface hydrophobicity of room temperature vulcanized (RTV) silicone rubber (SIR) due to immersion in acid, alkali and saline solutions has been studied as a function of immersion time and concentration. The loss and recovery of the hydrophobicity is correlated with the solute and the absorption of water during immersion and its subsequent desorption in air. The hydrophobicity is determined by measuring the static contact angle between the tangent to a droplet of distilled water and the horizontal RTV-SIR coating surface. The surface tensions of solutions were measured before and after the RTV-SIR coatings were immersed in solutions. The values show the effect of solution on RTV-SIR coating.

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... As the result of these changes, the polymer may lose elasticity, become brittle, and lose the mechanical strength. As well, increased surface roughness or loss of the polymer matrix could cause loss of surface hydrophobicity and lead to increased leakage current [7]. As a result of such deterioration of insulation characteristics, inservice failures can occur. ...
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