The presentation reports a systematic examination on electrostatic charge associated with Lambourn wear testing of non-conductive rubber compounds. Shortly after a wear test, electric surface potential was measured from the worn surface of a specimen in standstill. In comparison to a compound of natural rubber, the corresponding compound of cis-polybutadiene rubber exhibited an obviously faster rate of exponential decay for surface charge in air. With the same specimen of silica-filled polybutadiene compound on the same sandpaper, unexpected charge polarity reversal was observed from repeated wear tests. However, sample torque during a wear test or wear loss of material remained mostly stable.

• Shortly after a wear test at the slip ratio of 8% for 30s, surface potential from the worn surface of a rubber specimen reached ~-1 kV
• On the counter sandpaper surface, surface potential is of low magnitude, which can be partially rationalized with a geometric consideration
• From the worn surface of a rubber specimen the rate of exponential decay for surface potential varied across the compounds examined
• From repeated wear tests with the same silica-filled polybutadiene compound on the same sandpaper, a gradual reversal of charge polarity was observed
• Sample torque during a wear test and volume loss of material from a wear test remained mostly stable, without obvious correlation with surface charge