NÓBREGA, R. B.; http://lattes.cnpq.br/8566102268241861; NÓBREGA, Raphael Borges da.
Resumo:
In this research the performance of polymeric coatings applied to suspension glass
insulator was evaluated. The coatings were composed of Silicone Rubber at Room
Temperature Vulcanized added to alumina trihydrate and a new filler at different mass
proportions. The new filler was electrically characterized by measuring of this dielectric
constant and loss tangent. Insulators samples coated with various compositions were
subjected to cyclic salt fog tests whose purpose was to degrade the insulation. The
performance of the coatings was evaluated from leakage current measurements,
harmonic analysis and monitoring recovery of hydrophobicity. The dielectric constant
of the new filler was approximately 3,0 over wide frequency range and loss tangent
around 10-3. The evaluation of leakage current peak values showed that the addition of
low concentrations of new filler to Silicone Rubber provided good performance
isolation. Analysis of Total Harmonic Distortion and the ratio between 3rd and 5th
harmonics showed the aging of samples during the test. Monitoring of hydrophobicity,
after execution the cyclic salt fog test indicated that the coatings showed partial or total
recovery of hydrophobicity. In general, the best results were obtained for the coatings
that contained 5 wt% of the new filler.