Conductivity Current and Electric Breakdown Properties of Thermally Aged Nano Silicone Rubber

In this study, pure, Nano-Al
2
O
3
and Nano-MgO silicone rubber are used to study the conductivity current characteristic and electric breakdown property after thermal aging. After 20 days thermal aging, all three kinds of silicone rubber experience decrease of conductivity current. For further aging of 40 days, the conductivity current of pure silicon rubber increases while that of Nano-Al
2
O
3
and Nano-MgO almost remain the same as the conductivity of 20 days aging. After 20 days thermal aging, the electric breakdown field of all three kinds of silicone rubber increase. As the thermal aging continues to 40 days, the electric breakdown field of pure silicone rubber decrease from 107 kV/mm to 92 kV/mm, while that of Nano-Al
2
O
3
, Nano-MgO silicone rubber only decrease by 3 kV/mm and 5 kV/mm respectively. We believe that the decrease of conductivity current and increase of electric breakdown field of all three kinds of silicone rubber during the beginning of thermal aging are due to the further vulcanization. The reason that Nano-Al
2
O
3
and Nano-MgO silicone rubber shows better anti-aging properties in the further thermal aging period can be contributed to the better heat-conducting property which results in better heat dispersion