RTV silicone rubber hydrophobicity loss and recovery character under AC corona

Abstract

In this paper, the effect of AC Corona on the hydrophobicity of room temperature vulcanizing (RTV) silicone rubber materials is studied with a pin-plate electrode corona accelerate aging model. Experiments show that AC corona can make the RTV specimen hydrophobicity lose rapidly, further, the hydrophobicity recovery character of RTV specimen is also researched through a long time of corona test, as a result, it is found that the RTV specimen hydrophobicity recovery speed is not continuous, but having an alternate process of "speed up" and "slow down". After corona time reaches a certain time, the hydrophobicity recovery time dramatically becomes longer but it still can not fully restore to the initial value in the end. meanwhile research find that when the corona time is in a certain range, after the hydrophobicity recovery, the final static contact angle is much larger than the initial value before the corona.

Self-Healing Silicones for Outdoor High Voltage Insulation: Mechanism, Applications and Measurements

“…It is worth mentioning that the hydrophobicity recovery speed depends on corona exposure time and physical and chemical variations on silicone rubber surface [41,63]. It has been found that recovery speed in a long-corona aging test is not continuous and differs with corona aging time [64,65]. In addition, the hydrophobicity recovery becomes accelerated during the early stage of corona aging, possibly due to the increased production of LMW siloxanes.…”