Thermally stimulated discharge current and DC resistivity of ethylene propylene rubberwith various Pb concentrations
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DC resistivity of extruded ethylene propylene rubber (EPR) samples with various Pb concentration have been measured under wet conditions as a function of electrical field at selected temperatures in a range from 20 to 100°C. The temperature and electrical field coefficients of resistivity have been calculated. Thermally stimulated discharge current (TSDC) has also been measured and a broad positive peak has been observed for three EPR samples. It has been found that the resistivity of EPR is not sensitive to the Pb concentration within the range of 0 to 5 parts per hundred base resin (phr). The results show that the resistivity of EPR varies non-linearly with both temperature and electrical field. The temperature coefficient of resistivity α of EPR has been measured to be ∼0.1 K−1 for all the samples with various Pb concentration. The electrical field coefficient of resistivity β of EPR at room temperature is small and increases with temperature. Increasing Pb content increases slightly the electrical field coefficient β of resistivity. Based on a space charge limited conduction model, the trap depth of EPR has been estimated. TSDC measurements indicate that doping with Pb increases both the density of charge carriers and the number of deep traps simultaneously. The broad TSDC peak reveals that there must be a distribution rather than just a single value of the trap depth.
KeywordsConduction Model Positive Peak Deep Trap Ethylene Propylene Trap Depth
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- 1.R. N. HAMPTON, F. CHANG and S. B. HOBDELL, CIGRE Session 2000, P2-001.Google Scholar
- 2.V. BUCHHOLZ, “Finding the Root Cause of Power Cable Failures” (Electric Energy Publications Inc., 2004) http://www.jaguar-media.com/english.
- 3.R. KARPELES and A. V. GROSSI, “EPDM rubber technology,” Handbook of Elastomers, 2nd edn., edited by A. K. Bhowmick and H. L. Stephens (Marcel Decker, Inc., New York, 2001) p. 845.Google Scholar
- 4.J. A. RIEDEL and R. V. LAAN, “Ethylene Porpylene Rubbers,” The Vanderbilt Rubber Handbook 13th edn. (R.T. Vanderbilt Co., Inc., Norwalk, CT, 1990) p. 123.Google Scholar
- 5.G. V. STRATE, Ethylene Propylene Elastomers, vol. 6 (Encyclopedia of Polymer Science & Engineering, 1986) p. 522.Google Scholar
- 6.N. CHIWATA, “Deterioration characteristics of rubber insulation materials subjected to electrical stress under water immersion,” Nippon Gomu Kyokaishi, 76(4) (2003) 129 (General Review in Japanese).Google Scholar
- 7.L. HARRIMAN, “Environmental, health and safety issues in the coated wire and cable industry,” Technical Report No. 51 April 2002 University of Massachusetts Lowell. Website: http://www.turi.org/content/content/download/913/4501/file/Wire_Cable_TechReport.pdf.
- 8.F. CHANG, Manuscript for the 14th International Symposium on High Voltage Engineering, in preparation.Google Scholar
- 9.B. ALADENIZE, R. COELHO, J. C. ASSIER, H. JANAH and P. MIREBEAU, Jicable'99 (1999) p. 557.Google Scholar
- 10.F. CHANG, R. N. HAMPTON and S. B. HOBDELL, in Jicable'99 (1999) p. 685.Google Scholar
- 11.G. KAMPF, “Characterization of Plastics by Physical Methods” (Hanser Publishers, Munich Vienna, New York, 1986).Google Scholar
- 12.J. C. FOTHERGILL and L. A. DISSADO, in “Electrical Degradation and Breakdown in Polymers” (Peter Perigrinus Publishing, London, 1992).Google Scholar
- 13.C. FANGGAO, G. A. SAUNDERS, E. F. LAMBSON and R. N. HAMPTON, in Proceedings of the International Conference on Electrical, Optical and Acoustic Properties of Polymers EOA III (The institution of Civil Engineers, Great George Street, Westminster, London SW1P, 16–18th September 1992).Google Scholar
- 14.C. FANGGAO, University of Bath M. Phil. thesis (1992).Google Scholar