Evaluation of the electrical properties and mechanical behavior of insulator’s composite core in harsh environments

Abstract

Recent developments in applying composites in different industries result in replacing traditional materials with them. Polymer matrix composites have become one of the most popular advanced materials in the industries due to their peculiar properties, appropriate cost, and various and easy manufacturing methods. In this project, electrical, physical and mechanical properties of glass fiber reinforced polymer (GFRP) composites including acid absorption, breakdown voltage, and tensile strength have been investigated in order to be used as insulators in power transmission lines. In order to identify the chemical structure of neat resins and their composites, and also determining the possibility of bonding between polymer and glass, Fourier Transform Infrared Spectroscopic (FTIR) test was conducted. Regarding high voltage tests, a direct correlation was found between the amount of absorbed moisture by the specimens and the amount of breakdown voltage. The composites were degraded because of exposing, and this behavior was verified by Scanning Electron Microscopy (SEM) and Atomic Absorption Spectrometry (AAS) analysis. The results indicated a drop of 2.53% and 2.83% in tensile strength for E-glass epoxy and polyester composites with acid aging, respectively. Also, the breakdown voltage declined to 32 and 21 kV mm−1 after the moisture content reached 0.1% and 0.27% for E-glass epoxy and polyester composites, respectively. It can be concluded that epoxy matrix composite is more resistant to acid exposure compared to polyester matrix composite and is more suitable to be used in power transmission lines.