Silicone films with high stiffness and increasing permittivity through dipole-grafting

Dielectric elastomer actuators (DEAs) are smart materials that can be optimized by modifying the dielectric or mechanical properties of the electroactive polymer. The incorporation of inorganic particles in silicone elastomers shows a permittivity enhancement and undesired stiffening. We present another concept to obtain comparable properties by dipole grafting. Therefore, the organic dipole N-ally-N-methyl-4-nitroaniline is grafted in competition with the vinyl terminated PDMS to a hydrosilane cross-linker forming the PDMS network. With this procedure PDMS films with up to 25 wt% of the dipole were solvent casted and the chemical, mechanical, electrical, plus electromechanical properties of these novel materials were investigated.