Comparative study of SiR/EPDM containing nano-alumina and titanium dioxides in electrical surface tracking

The combination of polymer materials, such as silicone rubber (SiR) and ethylene propylene diene monomer (EPDM), has become one of the potential developments of new polymer insulator with superior characteristics. SiR/EPDM with a ratio of 50:50 weight percentages had produced the optimal electrical and mechanical properties of polymer composites. However, the study of these balanced blends with inclusion nanofillers remains limited and has yet to be completely explored. In the current research, SiR/EPDM blends were prepared with two types of nanofillers, namely, Al
₂
O
₃
and TiO
₂
. The loading concentrations of the nanofillers for each specimen were 1, 2, 3, 4, and 5 Vol%. The effects of the Al
₂
O
₃
and TiO
₂
nanofillers with different loading concentrations on the surface-tracking characteristics were investigated. Experimental results revealed that the addition of nanofillers to the SiR/EPDM composite significantly improved the performance of the electrical surface-tracking resistance, thereby decelerating the aging process or minimizing damage to the surface. Moreover, experimental results showed that SiR/EPDM filled with 1 Vol% of the Al
₂
O
₃
nanofiller had an improved tracking time performance than the SiR/EPDM filled with 2 Vol% of the TiO
₂
nanofiller had. The tracking time and thermal conductivity characteristics of both nanocomposites were higher than those of the unfilled SiR/EPDM.