Hydrophobic transfer of RTV silicone rubber aged in single and multiple environmental stresses and the behavior of LMW silicone fluid

摘要

This paper describes the hydrophobic transfer of unfilled room temperature vulcanized silicone rubber (RTV) resulting from UV radiation, corona discharges, high temperature, and a deposition of hydrophilic layer. The chemical and morphological structure at the surface layer and the migrating behavior of low molecular weight (LMW) silicone fluid from the bulk on to the surface top layer are investigated in order to elucidate the mechanism responsible for the hydrophobic transfer of RTV silicone rubber. It is shown that UV radiation and high temperature reduce highly mobile LMW silicone fluid, which reduces the recovery ability of the hydrophobicity. On the contrary, corona discharges produce highly mobile LMW silicone fluid that is formed as byproducts of corona aging, which promotes the hydrophobicity recovery and provides stability against other stresses.