Influence of single and multiple environmental stresses on tracking and erosion of RTV silicone rubber

Single and multiple effects of UV, corona, thermal, water absorption and acid rain stresses on the tracking and erosion characteristics of room temperature vulcanized silicone rubber (RTV) are investigated. It is shown that corona stress and water absorption stress decrease the tracking and erosion resistance of RTV, while thermal stress and UV stress improve it. Synthetic acid rain, 500/spl times/ stronger than actual rain in Japan, cannot induce the change in the tracking and erosion characteristics. RTV subjected to simultaneous multiple stresses also is evaluated. Significant variations in the tracking and erosion resistance appear. Chemical and morphological analysis for assessing the aging level is carried out by scanning electron microscope (SEM)-energy dispersive X-ray (EDX), attenuated total reflection (ATR)-Fourier transform infrared (FTIR) and differential scanning calorimetry (DSC). In this study, DSC plays an important role to detect boiling and combustion temperatures of byproducts affecting tracking and erosion. Noteworthy results are obtained in that the decrease in the resistance to tracking and erosion is related to the formation of byproducts that burn at low temperature (170 to 275/spl deg/C).

[1]  T. Tokoro,et al.  Effect of water salinity and temperature on the hydrophobicity of ethylene propylene diene monomer insulator , 1996, Proceedings of Conference on Electrical Insulation and Dielectric Phenomena - CEIDP '96.

[2]  R. Hackam,et al.  Role of the size of particles of alumina trihydrate filler on the life of RTV silicone rubber coating , 1995 .

[3]  Polymeric outdoor insulation , 1990 .

[4]  Kang-Sik Park,et al.  Surface degradation of silicone rubber under accelerated aging condition , 1997, IEEE 1997 Annual Report Conference on Electrical Insulation and Dielectric Phenomena.

[5]  R. Gorur,et al.  Surface recovery of silicone rubber used for HV outdoor insulation , 1994 .

[6]  R. Gorur,et al.  A laboratory test for tracking and erosion resistance of HV outdoor insulation , 1997 .

[7]  R. Gorur,et al.  Surface hydrophobicity of polymers used for outdoor insulation , 1990 .

[8]  A. E. Vlastos,et al.  Performance and ageing of polymeric insulators , 1997 .

[9]  George G. Karady,et al.  Aging in silicone rubber used for outdoor insulation , 1992 .

[10]  D. Koenig,et al.  Multifactor-surface-tests of organic insulating materials in the early stage of degradation , 1996, Conference Record of the 1996 IEEE International Symposium on Electrical Insulation.

[11]  R. Chang,et al.  Optimization of tracking resistance, erosion resistance and hydrophobicity for outdoor insulation materials , 1997, Proceedings of 5th International Conference on Properties and Applications of Dielectric Materials.

[12]  M. Shah,et al.  Polymer outdoor insulating materials. Part III-Silicone elastomer considerations , 1997 .

[13]  N. Yoshimura,et al.  Surface hydrophobicity of water-absorbed outdoor polymer insulating materials , 1997, Proceedings of 5th International Conference on Properties and Applications of Dielectric Materials.

[14]  K. Izumi,et al.  Diffusion of low molecular weight siloxane from bulk to surface , 1999 .

[15]  K. Naito,et al.  TIME VARIATION OF HYDROPHOBICITY AND WEIGHT OF SILICONE RUBBER IMMERSED IN WATER , 1997 .

[16]  Seiji Kumagai,et al.  Contamination performances of silicone rubber insulator subjected to acid rain , 1998 .

[17]  R. Hackam,et al.  Thermal characteristics of RTV silicone rubber coatings as a function of filler level , 1992, [Proceedings] 1992 Annual Report: Conference on Electrical Insulation and Dielectric Phenomena.

[18]  R. Hackam,et al.  Chemical changes at the surface of RTV silicone rubber coatings on insulators during dry-band arcing , 1994 .

[19]  Seiji Kumagai,et al.  Research in Japan on the tracking phenomenon of electrical insulating materials , 1997 .

[20]  C. Burns,et al.  Accelerated environmental and electrical aging of polymer insulators , 1996, Proceedings of Conference on Electrical Insulation and Dielectric Phenomena - CEIDP '96.

[21]  S. M. Gubanski,et al.  Properties of silicone rubber housings and coatings , 1992 .

[22]  R. Hackam,et al.  Hydrophobic behavior of insulators coated with RTV silicone rubber , 1991 .

[23]  C. Weschler,et al.  Pyrolysis gas chromatographic-mass spectrometric identification of poly(dimethylsiloxane)s , 1980 .

[24]  A. E. Vlastos,et al.  Surface structural changes of naturally aged silicone and EPDM composite insulators , 1991 .

[25]  M. Nishida,et al.  Tracking resistance of organic insulating materials by merry-go-round test method , 1988, Proceedings., Second International Conference on Properties and Applications of Dielectric Materials.

[26]  Shigeo Kobayashi,et al.  Effects of Sample Temperatures on Tracking Resistance of Organic Insulating Materials , 1996 .

[27]  N. Yoshimura,et al.  Solid residue formation of RTV silicone rubber due to dry-band arcing and thermal decomposition , 1998 .

[28]  M. Ishiwari,et al.  Deterioration of silicone rubber for polymer insulators by corona discharge and effect of fillers , 1998, 1998 Annual Report Conference on Electrical Insulation and Dielectric Phenomena (Cat. No.98CH36257).

[29]  B. Du,et al.  Effects of Atmospheric Pressure on Tracking Failure of Organic Insulating Materials , 1995 .

[30]  B. Du,et al.  Effects of Gamma-rays Irradiation on Tracking Resistance of Organic Insulating Materials , 1996 .

[31]  S. Gubanski,et al.  Wettability of naturally aged silicon and EPDM composite insulators , 1990 .