Properties of nanofillers/crosslinked polyethylene composites for cable insulation

In this work, we report the effect of nanofillers and filler loading on mechanical, physical, dielectric, and thermal properties of the crosslinked polyethylene (XLPE) matrix. XLPE filled with 0.5-2% of zinc oxide (ZnO), aluminium oxide (Al2O3), and organoclay (OMMT) nanofillers prepared by melt mixing with a single screw extruder followed by hot press moulding. Nanocomposites were tested as per ASTM standard methods and characterized with tensile test, water absorption, linear rate of burning, dielectric breakdown strength, and thermal stability. Scanning electron microscopy (SEM) was used to examine the surface morphology of the nanocomposites. The results showed that addition of nanofillers improved tensile strength, elongation at break, Young's modulus, burning rate, dielectric breakdown strength, and decomposition temperature. However, water absorption increased with time due to the hydrophilic properties of nanofillers. In general, based on the properties measured Al2O3 exhibits the highest properties than those of ZnO and OMMT nanofillers. Addition of 1.5% of Al2O3 in XLPE matrix has led to the improvement in tensile strength, elongation at break, Young's modulus, burning rate, and dielectric breakdown strength as compared to the unfilled polymer. J. VINYL ADDIT. TECHNOL., 25:E147-E154, 2019. (c) 2018 Society of Plastics Engineers