Comparison of how graphite and shungite affect thermal, mechanical, and dielectric properties of dielectric elastomer-based composites

Abstract

The aim of this work involved comparing the effect graphite and shungite have on the properties of dielectric elastomer-based materials. For this reason, dielectric elastomer–Sylgard (S) was filled with 1, 3, 5, 10, and 15 wt.% of graphite (G) and shungite (Sh). The structure of the obtained materials was studied by means of scanning electron microscopy and atomic force microscopy. The influence of the introduced additives on the thermal stability of the obtained composites was evaluated using thermogravimetry. Moreover, the mechanical properties and the dielectric constant of the elastomer with an addition of graphite and shungite were determined. Obtained results allowed us to establish that the presence of graphite as well as shungite significantly influences mechanical as well as dielectric properties. Additionally, the optimum mass of additives, allowing to increase the dielectric constant without the significant decrease of strain at break, was indicated. In the case of materials containing graphite, regardless of the filler content (1–15 wt.%), the mechanical as well as the dielectric properties are improved, while in the case of composites with an addition of shungite exceeding the 5 wt.% of filler content, a reduced tensile strength was observed.