Tracking and erosion resistance stability of highly filled silicone and alloy materials against electrical and environmental stresses

Tracking and erosion resistances of highly filled silicone rubbers (SIRs) and of polymer alloys made from SIR and ethylene vinyl acetate copolymer (EVA) were evaluated after being aged by the stress of acid rain, UV, corona or water absorption. It was demonstrated whether or not high-level fillers could sufficiently protect tracking and erosion resistances against ageing. Acid rain dissolved alumina trihydrate filler at the surface layers of various polymers tested, thereby reducing the tracking and erosion resistances of those polymers. UV and corona stresses affected the basic polymers rather than the fillers, decreasing the polymers´ resistances to tracking and erosion, while highly filled SIR and alloys maintained their tracking and erosion resistances after absorbing large amounts of water.