Effect of Hybrid Nano and Micron Fillers on the Dielectric Properties of Glass Epoxy Composites

Bommegowda K. B., N. M. Renukappa, J. Sundara Rajan

Epoxy resin, glass woven fabric, dielectric constant, dissipation factor, impedance, nanofillers, micron fillers, hybrid fillers.

Failure of polymer composites in many critical applications has mandated the need for improvements in the electrical, mechanical, and thermal properties using fillers. In this study, different fillers like silicon dioxide, alumina, silicon carbide, molybdenum disulphide, silicon carbide, and graphite have been incorporated into the epoxy matrix which is reinforced with ECR glass woven fabric. The dielectric properties of the hybrid composites namely dielectric constant, dissipation factor, and impedance was determined over a frequency range of 20 Hz to 10 MHz, and at three temperatures namely 25, 50 and 75±2⁰ C. It is observed that the dielectric constant is in the range of 4 to 11and the composite with molybdenum disulphide shows the highest dielectric constant. The composites show higher differences in the dielectric constant in the low-frequency range, but the differences are reduced at higher frequencies. This fact highlights the role of fillers at lower frequencies and the domination of the reinforced epoxy matrix at higher frequencies. The dielectric constant of hybrid fillers is higher than the composites with micron-sized fillers but are minimally lower than the corresponding values of the nanocomposites. In terms of dissipation factor, no significant differences are observed when the performance of hybrid composites when compared with composites with individual nano or micron-sized fillers. The impedance variations of hybrid composites with frequency are identical and it does not change with temperature and minor differences in magnitude are observed.  

https://dx.doi.org/10.31873/IJEAS.8.6.08