Electromechanical characterization of titanium-dioxide-filled SiR-EPDM blends

The aim of the research is to prepare a polymer composite material for high-voltage cable insulation purposes. Many researchers have blended a silicone rubber (SiR) and ethylene propylene diene monomer (EPDM) at different ratios to identify the composition which possesses excellent electromechanical properties. SiR-EPDM blends in 90:10 and 10:90 ratios were taken up for this study. To these polymer blends, metallic filler titanium dioxide (TiO ₂ ) with different densities have been used as the filler materials. The electromechanical performance and the physico-chemical behaviour of SiR-EPDM blends with filler addition were compared with SiR-EPDM blends of the same blend ratio without filler. The electromechanical parameters were measured according to the International Electrotechnical Commission (IEC) and ASTM standards. The surface morphology and filler dispersion were examined by the scanning electron microscopy images. The elemental compositions of the samples were obtained from the energy dispersive X-ray analysis. The changes in electromechanical behaviour of the samples were analysed from Fourier-transform infrared spectroscopy results. The investigations reveal that 5 wt% of high-density TiO ₂ -filled SiR-rich blend possesses the best electromechanical performance of all prepared samples.