Effect of Filler on the Deformation of Polydimethylsiloxane Composites under an Electric Field

The study considers some aspects of the development of new stimuliresponsive materials capable to reversible deformation under an electric field due to the Maxwell pressure. To increase the response of the material to an external stimulus, an approach of polymer composites formation was chosen. Particles of various nature and shape were considered as fillers: powders of iron, montmorillonite and cellulose. Composite elastomeric materials based on polydimethylsiloxane with a low filler content of 5 wt% have been obtained. The morphology of the filler particles was confirmed by electron microscopy. Mechanical properties of the materials in uniaxial tests were studied. The Young’s modulus and constants for the 3-parameter Yeoh model in the range of deformations up to 800 % were determined. The electrophysical properties of the materials, as well as their response to an electric field at different strengths of 0.84 and 2.5 kV/mm have been studied. The effect of the filler nature on the conductivity and permittivity of composite materials was revealed. The data of mechanical and dielectric studies indicate that the filler concentration is below the percolation threshold for all composites. The composite with cellulose exhibits the greatest response to an external stimulus over the considered materials, which is determined by the balance of two factors: the value of Young’s modulus and the values of electrophysical characteristics. Directions for further research were determined and the prospects for the dielectric elastomers creation with predetermined properties were briefly discussed