Surface studies of corona-treated silicone rubber high-voltageinsulation

摘要

XPS (X-ray photoelectron spectroscopy) and microscopy studies ofthe brittle layer that is produced have established that corona exposureforms a wettable silica-like layer on the surface of mostpolydimethylsiloxane (PDMS) elastomers. This is consistent with similareffects from oxygen and inert gas plasma treatment. Such a layer cannotreadily reorient between hydrophilic and hydrophobic states at thesurface, suggesting that diffusion of low molecular weight PDMScomponents is an important mechanism of hydrophobic recovery. Therecovery is followed by water contact changes which show differencesbetween conventional peroxide-cured and platinum-cured siliconeelastomeric materials. These latter materials recover more slowly. XPSchemical shift data also indicate interesting oxidation differences insilicon and carbon in the surface of these two classes of elastomers