Investigation of insulation and aging characteristics of high voltage PVC/ ZnO nanocomposites insulation under Electro-UV stresses /

Abstract

Polymers may be degraded by exposure to UV radiation and electrical stress in their operational environments. As PVC cable insulation applications, this study evaluates the performance of novel PVC nanocomposites with ZnO nanoparticles under combined Electro-UV aging conditions. PVC nanocomposites with different concentration of ZnO nanoparticles (0, 1, 3, 5, and 7 wt%) were prepared by using the melt mixing method. Finally, these were compression molded to create 1.5 mm thick circular samples. X-ray diffraction (XRD) was used to further analyze the distribution and dispersion of ZnO fillers in the PVC matrix, including establishing the uniformity and efficiency of filler incorporation. This would be critical for investigating how filler dispersion affects the overall structural, thermal and electrical properties of nanocomposites when subjected to the UV and electrical stresses. The Prepared PVC-ZnO nanocomposite samples were analyzed using a range of techniques including X-Ray Diffraction (XRD), STRI hydrophobicity test, contact angle test, leakage current test and both temperature and frequency dependent properties. The analyses were carried out every 150 hours under UV exposure at 5.11 mW/cm² and 450 hours aging period. The structural, thermal and electrical properties of the nanocomposites were monitored at the 150hour interval to monitor the progress of UV induced degradation. Surface degradation took place on all samples however a increase in leakage current was also seen with increasing age. While the unmodified PVC did not surpass, PVC nanocomposites reinforced with ZnO nanoparticles did. The increased structural integrity, and increase in surface area and energy of the nanoparticles lead to retention of the composite integrity under UV stress, attributed to superior performance of ZnO filled samples. The results here in indicate that the ZnO nanoparticles had increased the nanocomposites' resistance to UV induced degradation, reducing surface degradation and controlling increase of leakage current. The findings will indicate the effectiveness of ZnO as a nanofiller to boost the durability and electrical properties of PVC nanocomposites exposed to severe environmental condition.