Effect Of Temperature and Water on the Insulation Characteristics of Novel High Voltage Polyamide Nanocomposite Insulators /

Abstract

Polyamide and its nanocomposites have shown remarkable properties to be used for electrical applications, especially in high voltage cables or motor insulation applications. However, in these environments the insulation materials are exposed to humid and high temperature conditions which deteriorates the structure of polyamide-based insulators hence degrades its electrical properties. To analyze the effect of temperature and humidity on dielectric properties, neat polyamide (nPA/PA-0), 1wt.% polyamide ZnO nanocomposite (PA-1), 3wt.% polyamide ZnO nanocomposite (PA-3), 5wt.% polyamide ZnO nanocomposite (PA-5) and 7wt.% polyamide ZnO nanocomposite (PA-7) were prepared. These composites were then subjected to accelerated conditions of humidity and temperature (85°C & 85% RH) in a hydrothermal aging chamber for 300 hours. The relative permittivity and tan δ depending on temperature and frequency of each sample were analyzed after every 100 hours. The analyses showed that increase in temperature results in high relative permittivity and loss factor and among all the nanocomposites PA3 performed better. The investigation for frequency dependency of dielectric properties

showed

that relative permittivity and dissipation factor decrease with increase in frequency for which PA-1 performed better. The effect of elevated temperature conditions was significant as the aged composites showed an increase in the values compared to unaged composites but they were in acceptable limit required for a good insulating material. The effect of addition of ZnO was also observed as nanocomposites performed better than the neat polyamide and nano filler performed even better due to intactness of composite structure or greater surface area and surface energy.