Hydrophobic recovery of polydimethylsiloxane after exposure to partial discharges as a function of crosslink density
2001 (English)In: Polymer, ISSN 0032-3861, E-ISSN 1873-2291, Vol. 42, no 17, 7349-7362 p.Article in journal (Refereed) Published
Polydimethylsiloxanes with different crosslink densities were exposed to corona discharges or GHz air plasma and studied by contact angle measurements, X-ray photoelectron spectroscopy, optical microscopy, scanning electron microscopy and atomic force microscopy. The degree of surface oxidation increased with increasing exposure time with a limiting depth of 100-150 nm. Surface oxidation was faster in more highly crosslinked polymers. Within the oxidised layer, a brittle, microporous silica-like layer with a minimum organic silicone content of 40% gradually developed with increasing exposure time. The strain at which the silica-like layer cracked decreased with increasing dose of corona or air plasma. The hydrophobic recovery following the corona/air plasma exposure occurred at a slow rate by diffusion of oligomers through the microporous but uncracked silica-like layer or at a much higher rate by transport of oligomers through cracks in the silica-like layer.
Place, publisher, year, edition, pages
2001. Vol. 42, no 17, 7349-7362 p.
polydimethylsiloxane, electrical discharges, hydrophobicity, epdm composite insulators, naturally aged silicone, surface
IdentifiersURN: urn:nbn:se:kth:diva-20642ISI: 000168797900014OAI: oai:DiVA.org:kth-20642DiVA: diva2:339338
QC 201005252010-08-102010-08-10Bibliographically approved