Understanding the impact of gamma irradiation on electrical and mechanical properties of epoxy nanocomposites

Abstract

In this work, the influences of gamma irradiation on the electrical and mechanical properties of the epoxy nanocomposites were studied. The exfoliation characteristics of epoxy nanocomposite material analyzed through TEM studies. It is shown that the impact and flexural strength of the material is high with epoxy nanocomposites and gets reduced with the gamma‐irradiated specimen. The AC breakdown strength of the epoxy nanocomposites is high compared with the base epoxy resin. It is also observed that a reduction in permittivity and tan(δ) of epoxy resin added with 1 wt % of nanoclay. Increase in percentage of clay shows increase in permittivity and tan(δ). Gamma irradiation of epoxy nanocomposite material shows increase in permittivity. The volume resistivity of the material is high with epoxy nanocomposite and is less with gamma‐irradiated specimen compared with virgin specimen. The impact strength and flexural strength indicates correlation with breakdown strength of the material. It is observed that the increase in applied voltage shows an increase in magnitude of the charge density in the insulation structure. With the gamma‐irradiated specimen, the charge density (for the applied electric field) is less compared with the virgin specimen. Electric field analysis indicates that the electric field is uniform in the bulk volume of the epoxy nanocomposite material. The rate of charge decay is high with gamma‐irradiated specimen compared with virgin specimen. It is realized that material with lower resistivity has faster decay of stored charge. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Effect of chemical corrosion on charge transport behaviour in epoxy/Al 2 O 3 nanocomposite irradiated by gamma ray

“…With the addition of nanoparticle, the charge transport behaviour changes, which is in agreement with previous studies [6,18]. The depth of traps for nanocomposite is deeper than that for ER samples.…”

“…The structure changes of ER and its nanocomposites before and after acid/alkaline corrosion at different temperatures are shown in Figures 3-5. The corrosion mechanism has been mainly studied, rather than the influence of nanoparticle content on ER-based samples in physical and chemical structures, which has been discussed in previous studies [6,18]. In order to clearly show the effect of chemical corrosion on the structure of samples, the typical results are presented in this section.…”

“…Over the past decades, the method of adding nanoparticles to ER has been extensively reported to improve its insulation performance under irradiation [6][7][8][9]. R. Karpagam et al prepared ER/clay nanocomposites with different nano-filler contents (1-10 wt%) to investigate the effect of gamma-ray irradiation on the breakdown strength; the results showed that the breakdown strength of the composite containing 1-wt % nano-clay at an irradiation total dose of 20 kGy increased by approximately 25.8% [6]. Y.…”

“…R. Karpagam et al. prepared ER/clay nanocomposites with different nano‐filler contents (1–10 wt%) to investigate the effect of gamma‐ray irradiation on the breakdown strength; the results showed that the breakdown strength of the composite containing 1‐wt% nano‐clay at an irradiation total dose of 20 kGy increased by approximately 25.8% [6]. Y. Gao et al.…”

Effect of gamma irradiation on space charge and charge trap characteristics of epoxy–MgO nanocomposites

“…It is noticed that with varying dosage rate, the average amount of accumulated charge differs because of the irradiation induced mechanisms. Karpagam et al studied the impact of gamma irradiation on epoxy–clay nanocomposites and observed less space charge density with gamma‐irradiated specimens [28].…”