Electrical Property of Polypropylene Films Subjected to Different Temperatures and DC Electric Fields

A polypropylene (PP) film is usually used as a dielectric material in capacitors as well as cables. However, PP films may degrade because of the combined effect of temperature and electric field. In an earlier study, plain PP films and PP films loaded with nano-metric natural clay were studied under sinusoidal (AC) electric fields at power frequency and temperatures above the ambient. To better understand the electrical characteristics of PP film under various conditions, the objective of this study is to determine the time-to-breakdown of the plain PP and PP filled with 2% (wt) natural nano-clay when subjected to time-invariant (DC) electric fields at elevated temperatures. In order to achieve this objective, the effects of uniform as well as non-uniform electric fields were compared at the same temperature for the PP film. In this study, experimental results indicated that the time-to-breakdown of all PP films, plain or filled with nano-clay, decreases with the increase in electric field intensity, non-uniformity of the electric field, and temperature. It was also found that the time-to-breakdown of PP film filled with 2% (wt) natural nano-clay under DC electric field is longer and less sensitive to temperature. Furthermore, when compared with the results under the uniform electric field, PP film filled with 2% (wt) nano-metric natural clay indicates shorter time-to-failure under non-uniform DC electric fields. Finally, the morphology of the samples was observed by digital camera, optical micrography, and SEM, to better understand the mechanism of the breakdown.

Degradation of NanoDielectrics

Type and concentration of nanoparticles inside polymers can help or limit the chain portability and lead to diminishing or expanding electric encasing on connect or cutoff for versatile accuse and the development of charge transporters, especially polymer dielectrics. This chapter sheds light on the degradation of nanodielectrics which handled the electrical degradation and lifetime. The chapter contains also the different nanodielectrics thin films and presents the effect of degradation of nanodielectrics under AC and DC electric fields. It contains details about thermal stability analysis. Finally, this chapter draws attention on the recommendation for investment nanodielectrics technologies.