Space charge characteristics of HTV silicone rubber after corona aging

The space charge characteristics of polymers can be used as an effective means of assessing the aging degree of polymeric materials. In this paper, corona aging test of silicone rubber has been carried out based on the orthogonal test method. Pulsed Electro-Acoustic (PEA) method is used to measure the distribution of space charge of the samples after aging. According to the measurement results, it can be observed that the current peak of the space charge distribution curve increases with the deepening of aging. Using the PEA space charge density as a test index, the range analysis and variance analysis results both show that corona voltage has the maximum significance on the test index, followed by the aging time, while the relative humidity with the minimum significance. Combined with the hydrophobicity test and SEM analysis, the conclusion can be obtained that the recovery of hydrophobicity has a lower speed and serious holes and traps appear on the surface gradually with the deepening of aging.