Controlling dielectric permittivity and dielectric loss by starch-coated silver nanoparticles in ethylene-propylene rubber

In this study, the effects of silver nanoparticles (AgNP) and starch‐coated ones (AgNP/starch) on dielectric properties of ethylene–propylene rubber (EPR) composites were compared. The dielectric permittivity of AgNP/EPR with 8 vol% of AgNP achieved 336 at 1 kHz which specifies the percolation threshold. AgNP/EPR composite with 6 vol% of filler as a near‐percolation sample was chosen to study the contribution of starch on dielectric properties. The AgNP/EPR composite showed relatively high dielectric permittivity and loss tangent ( , at 1 kHz), whereas AgNP/starch/EPR composite showed lower permittivity and loss ( , at 1 kHz), but with the advantage of more reduction in dielectric loss than dielectric permittivity. Moreover, better compatibility was observed between EPR and AgNP/starch particles, resulting in better dispersion of this coated filler, compared to AgNP. POLYM. COMPOS., 39:1303–1310, 2018. © 2016 Society of Plastics Engineers