Natural rubber is used to manufacture line-life equipment due to its insulating and flexibility characteristics. In order to provide safety to lineman, these pieces of equipment are periodically submitted to electrical maintenance tests. During these tests, corona discharges occur generating ozone gas which can react with natural rubber, thus ageing it and affecting its initial characteristics. This study shows changes caused by ozone exposure with concentrations prevailing during electrical tests in equipment made of natural rubber. The samples were tested with and without mechanical deformation and evaluated by microscopy and mechanical properties. Superficial changes were observed in samples which were not exposed to mechanical stress, while for mechanically stressed samples there were macroscopic cracks and decrease in the mechanical properties.
Natural rubber; ozone; degradation; mechanical properties
