Hydrophobic recovery of polydimethylsiloxane after exposure to partial discharges as a function of crosslink density

摘要: 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 atomic force microscopy. The degree of surface oxidation increased increasing exposure time a limiting depth 100-150 nm. Surface was faster in more highly crosslinked polymers. Within the oxidised layer, brittle, microporous silica-like layer minimum organic silicone content 40% gradually developed time. strain at which cracked decreased dose plasma. hydrophobic recovery following corona/air occurred slow rate diffusion oligomers through but uncracked much higher transport cracks layer.