Silicone dielectric elastomers based on radical crosslinked high molecular weight polydimethylsiloxane co-filled with silica and barium titanate

Abstract

A strategy, consisting in the use in tandem of two active fillers in different ratios with complementary effects: silica mainly as a reinforcing agent and barium titanate as dielectric permittivity enhancer, was proposed to optimize the electromechanical properties of the silicone elastomers. A high molecular mass polydimethylsiloxane-α,ω-diol (M w = 642000 g mol−1) was used as a matrix to prepare silicone composites which further were processed as films and crosslinked at high temperature. The morphological, thermal, and moisture behaviors of the films were studied by adequate techniques. The mechanical properties were estimated on the basis of normal and cyclic stress–strain curves. Dielectric spectra were recorded in the frequency range of 1–106 Hz at normal temperature. The voltages generated by a mechanical impulses created by falling of a metal ball of 7.1 g from a height of one hundred millimeters on the surface of the films placed between two electrodes ranged between 28.4 and 157.3 V mm−1.