corona resistant
1.The construction of Dupont corona-resistant polyimide film was analyzed by means of SEM and AFM, and the surface morphology of the original film and the corona- resistant film were compared with each other after aged.
2.In order to study the partial discharge mechanism of polyimide film used in frequency control motor, the electrical conduction current of both DuPont common polyimide film (100HN) and corona-resistant polyimide film (100CR) was measured before and after 8 hours corona-discharge aging under 10 kV/mm and 20 kV/mm. The results show that the electrical conduction current of 100CR is about one order of magnitude larger than that of 100HN.
3.The effect of alumina addition on dielectric properties of the composites was studied; the results show that the corona-resistant lifespan of PI film with 23% amount of alumina(counting as Al2O3) was more than 120 hours,about 30 times longer than pure PI film in the condition of 90 MV/m,50 Hz,0.1 mm air gap on the rod-plate electrode system which was made by us.
