Electrical insulation properties of silicone rubber under accelerated corona and thermal aging. Issue 3 (24th December 2020)

• Record Type: Journal Article
• Authors: Belhiteche, El Hadi; Rondot, Sébastien; Moudoud, Mustapha; Dony, Philippe; Jbara, Omar
• Is Part Of: Polymer engineering & science. Volume 61:Issue 3(2021)
• Page Start: 706
• Page End: 715
• Publication Date: 2020-12-24
• Subjects: corona discharge -- electrical properties -- FTIR‐ATR -- silicone rubber -- surface degradation -- thermal aging; Polymer engineering -- Periodicals; Polymers -- Periodicals; 668.9
• DOI: 10.1002/pen.25610
• Languages: English
• ISSNs: 0032-3888

Abstract

Abstract: A contactless method based on energy shift of high‐energy cut‐off of the x‐ray bremsstrahlung, the so‐called Duane Hunt Limit and a conventional low voltage electrical technique (three‐probes technique) is applied on thermal and corona aged silicone rubber (SiR) to measure, respectively, the surface potential, V s, and the surface resistivity, ρ s . The effect of aging on these quantities, representing the dielectric properties, is studied. The results are highly reproducible and highlight a good correlation between V s and ρ s . It was observed that thermal aging combined with electrical aging deteriorates more the electrical properties of the polymer than thermal aging alone. Explanations for electrical characteristics ( V s, ρ s ) change with aging are supported by attenuated total reflection Fourier transform infrared spectroscopy spectra analysis and a chemical mechanism of aging in three steps (i.e., oxidation‐polycondensation, degradation, and thermal cracking). The surface degradation of the polymer is revealed by images of surface morphology obtained by using scanning electron microscopy (SEM). Roughness is greater for combined thermal and corona aging mode compared to thermal aging alone. In addition, the surface degradation of SiR polymer is confirmed by the loss of its hydrophobicity. Abstract : Surface potential and surface resistivity as a function of aging time.