Figure 1. The relationship between the corona resistant lifetime and the average electric field intensity from the corona-aging tests of different kinds of nanocomposite films at different temperatures.

The curves are fitted by the least square method with power type and the error bars show the maximum and minimum value among the four repeated tests. (a) Pure PI (0 wt%) films. (b) 2 wt% PI/Al₂O₃ nanocomposite films. (c) 5 wt% PI/Al₂O₃ nanocomposite films.