THE LOSS AND RECOVERY OF HYDROPHOBICITY OF RTV SILICONE-RUBBER INSULATOR COATINGS

The results of a study on the loss and recovery of hydrophobicity of room temperature vulcanizing (RTV) silicone rubber insulator coatings in a salt-fog chamber are reported. These new results complement those previously reported on the ability of the coatings to suppress leakage current and insulator flashover. The temporary loss of hydrophobicity caused by dry band arcing and the recovery of hydrophobicity which follows is studied in depth. The gradual loss of hydrophobicity as determined from the leakage current and the contact angle measurements is shown to be related to the physical changes to the coating brought about by dry-band arcing. © 1990 IEEE