Degradation Assessment of Polyethylene-Based Material Through Electrical and Chemical-Physical Analyses

Abstract

The usability of any material hinges upon its stability over time. One of the major concerns, focusing on polymeric materials, is the degradation they face during their service life. The degradation mechanisms are deeply influenced by the aging temperature to which the material is subjected. In this paper, low-density polyethylene (LDPE) flat specimens were thermally aged under two different temperatures (90 °C and 110 °C) and analyzed. Specimens were characterized through both the most common mechanical and chemical measurements techniques (e.g., tensile stress, thermal analyses, oxidation induction time) and electrical measurements (dielectric spectroscopy, in particular), which are examples of non-destructive techniques. As a result, a very spread characterization of the polyethylene-based materials was obtained and a very good correlation was found to exist between these different techniques, highlighting the possibility of following the aging degradation development of polymers through electrical non-destructive techniques.

Life modeling analysis of Silane crosslinked polyethylene cables for nuclear applications

“…where ε' is the real part of permittivity defined as the dielectric constant of the material, ε'' is the imaginary part of permittivity related to the dielectric losses of the material, ω is the angular frequency of the wave and σ is the conductivity of the material [3][4][5][6].…”

“…In the recent years, electrical properties, in particular dissipation factor (Tanδ), gained more and more interest by some researchers since they appeared to be suitable for the evaluation of health condition of the cable with aging in a nondestructive way [3,6].…”

Aging Modeling of Low-Voltage Cables Subjected to Radio-Chemical Aging

“…This latter reasoning raised the possibility to explore other condition monitoring techniques which can overcome the EaB limitations. Among the different techniques, dielectric spectroscopy has been gaining more and more interest due to its numerous advantages, i.e., it is a nondestructive technique, it refers to the entire cable insulation and it has been successfully correlated to the aging development of the cable properties at various scales [3], [16][17][18][19][20]. However, the use of the tensile stress technique over many years allowed the development of a copious number of modelling approaches aiming at predicting the life of the LV cables through EaB [12].…”

Comparison of Mechanical and Low-Frequency Dielectric Properties of Thermally and Thermo-Mechanically Aged Low Voltage CSPE/XLPE Nuclear Power Plant Cables

“…During operation in the NPP environment, these LV cables are exposed to numerous stresses, thermal, radiation, electrical, and mechanical, which cause degradation in these polymeric materials [10]. The electrical and thermal stresses are the prominent aging factors for the high-voltage (HV) and medium-voltage (MV) cables [11]. For the LV cables, elevated temperature and radiation could be the major factors, along with the chemical contamination and mechanical stresses in some cases [10,12].…”

“…The reason for the application of this technique in this study is that dielectric spectroscopy as condition monitoring for NPP cables has recently become a focus of interest because of its non-destructivity. Several studies show promising results, and their future expansion is likely [11,12,[24][25][26][27][28][29][30][31]. From the results of dielectric spectroscopy measurement, deducted quantities were introduced because assigning one measure to the whole low-frequency spectrum makes it easier to analyze the changing of the dielectric spectrum with aging.…”