Accelerated test procedures for hydrothermal aging

Roggendorf, Christoph; Kessler, Michael R.; Schulte, Sabrina; Schnettler, Armin

doi:10.1109/elinsl.2010.5549754

Cited by 4 publications

(3 citation statements)

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“…Hui et al [8] demonstrated that hydrothermal aging causes the reduction of the electrical performance of the XLPE/silica nanocomposites. Roggendorf et al [9] evaluated the variation of dielectric properties of polyamide as a function of aging times such as dielectric loss factor, dielectric constant and dielectric strength. It was found that higher water absorption in the pressure cooker leads to higher dielectric constant and loss factor and lower dielectric strength.…”

Section: Introductionmentioning

confidence: 99%

Investigation of Hydrothermal Aging on Polyvinyl Chloride (PVC) Used in Medium Voltage Cables

Ouazzou¹,

Nedjar²,

Hocine³

et al. 2022

ACSM

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This investigation deals with the effect of hydrothermal aging on the electrical insulating properties of polyvinyl chloride used in medium voltage cables. The evolution of dielectric properties (dielectric loss factor, dielectric constant, dielectric strength and volume resistivity) as a function of aging time and temperature has been studied. After that, the mechanical characteristics (elongation at break and tensile strength) were also determined. Physico-chemical analysis was performed to highlight the structural changes induced by hydrothermal aging. Infrared spectroscopy using the Fourier transform (ATR-FTIR) and thermogravimetric analysis (TGA-DTA) have been performed. The results obtained show that the loss factor and dielectric constant increase gradually with the increase of temperature, while the volume resistivity decreases. At 100℃, the general shape of the curves giving the evolution of dielectric properties as a function of aging time shows that both loss factor and dielectric constant increase while those of volume resistivity and dielectric strength decrease. In the case of 80℃, the loss factor decreases slightly and the dielectric constant remains almost constant with aging time, whereas the volume resistivity and dielectric strength increase. The activation energy varies with aging time. The impact of hydrothermal aging on the properties of the material has been established in this study. At the beginning of aging, the degradation is mainly due to the elimination of molecular HCl. At more advanced stages of aging, the degradation is attributed to the elimination of HCl and double bonds formation followed by a change in color. Other consequences of the degradation like crosslinking and swelling of the samples are also noticed.

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Section: Introductionmentioning

confidence: 99%

Investigation of Hydrothermal Aging on Polyvinyl Chloride (PVC) Used in Medium Voltage Cables

Ouazzou¹,

Nedjar²,

Hocine³

et al. 2022

ACSM

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“…The diffusion and the absorption of water can lead to electrical failure of cables by water treeing as reported by Moreau et al [3] and Dissado and Fothergill [4]. Several researchers reported the degradation of polymers under hydrothermal aging [5][6][7][8][9][10].…”

Section: Introductionmentioning

confidence: 96%

“…Roggendorf et al [8] investigated the effect of hydrothermal aging on the electrical properties of fiber-glass reinforced with polyamide. The study shows a decrease in specific resistivity, and a raise in dielectric constant and dielectric loss factor.…”

Section: Introductionmentioning

confidence: 99%

Electrical Properties of Polyethylene Terephthalate under Hydrothermal Aging

Ait-Saadi¹,

Nedjar²

2023

MMEP

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During the working of rotating machines, dielectric materials are submitted to the action of humidity. At long term, their properties can degrade and the lifetime of devices will be reduced. This paper deals with the influence of hydrothermal aging on the electrical properties of polyethylene terephthalate. The insulation was aged in water at 80℃ and 100℃. The study shows that dielectric loss factor, permittivity, volume resistivity and dielectric strength were affected by aging. The change is attributed to the fact that the aging reduces molecular bonds causing a decrease in the viscosity. Thereby, the free volume and the mean free path raise. This process leads to the raise in the mobility of charge carriers. The evolution of activation energy versus aging time exhibits minimums and maximums resulting to the plasticization and the crosslinking of the material, respectively. The TGA thermograms indicate a variation of onset temperature with aging time. It was highlighted by TGA that the decomposition occurs following one step. The FTIR analysis points out a change in the intensities of the vibrational spectra after aging. The penetration of water within the dielectric induces differential inflations. The physical chemical analysis shows a modification in the molecular conformation of the polymer. The results are analysed and discussed.

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