A simple method for reducing inevitable dielectric loss in high-permittivity dielectric elastomers

Abstract

Abstract. Commercial viability of dielectric elastomers is currently limited by a few obstacles, including high driving voltages (in the kV range). Driving voltage can be lowered by either decreasing the Young's modulus or increasing the dielectric permittivity of silicone elastomers, or a combination thereof. A decrease in the Young's modulus, however, is often accompanied by a loss in mechanical stability, whereas increases in dielectric permittivity are usually followed by a large increase in dielectric loss followed by a decrease in breakdown strength and thereby the lifetime of the dielectric elastomer. A new soft elastomer matrix, with high dielectric permittivity and a low Young's modulus, aligned with no loss of mechanical stability, was prepared through the use of commercially available chloropropyl-functional silicone oil mixed into a tough commercial LSR silicone elastomer. The addition of chloropropylfunctional silicone oil in concentrations up to 30 phr was found to improve the properties of the silicone elastomer significantly, as dielectric permittivity increased to 4.4, dielectric breakdown increased up to 25% and dielectric losses were reduced. The chloropropyl-functional silicone oil also decreased the dielectric losses of an elastomer containing dielectric permittivity-enhancing TiO2 fillers. Commercially available chloropropyl-functional silicone oil thus constitutes a facile method for improved silicone dielectric elastomers, with very low dielectric losses.

Optimization Techniques for Improving the Performance of Silicone‐Based Dielectric Elastomers

“…[91,97,98] The chloropropyl group was initially introduced solely to allow for further functionalization. [91,97,98] The chloropropyl group was initially introduced solely to allow for further functionalization.…”

“…[97] The mechanism for this is still not understood, but nevertheless, it works for a wide range of composite systems. [97] The mechanism for this is still not understood, but nevertheless, it works for a wide range of composite systems.…”

“…A rather well-investigated system is silicone elastomers with chloropropyl groups covalently grafted to the PDMS backbone, as shown in articles. [91,97,98] The chloropropyl group was initially introduced solely to allow for further functionalization. The dielectric permittivity of the chloropropyl group was considered uninteresting, but measurements performed on this reference system revealed very promising results.…”

Degradation patterns of silicone-based dielectric elastomers in electrical fields

“…Such studies include synthetic incorporation of aromatic compounds [18] and chloropropyl groups [30,31] in the silicone polymer backbone. In this study we investigate the electrical breakdown patterns of two chloropropyl-functionalized silicone elastomers as prepared in Madsen et al [30] which break down electrically in rather different ways and we compare them to a silicone-based reference.…”

Electrical breakdown phenomena of dielectric elastomers

“…dipolar moieties in minute amounts the electrical breakdown strength can be increased. Such studies include incorporation of aromatics 16 and chloro propyl groups 25,26 on the silicone backbone. In this study we focus on the chloro propyl functionalized silicone elastomers prepared in Madsen et al 25 and investigate the electrical breakdown patterns of two similar chloro propyl functionalized silicone elastomers which break down electrically in a rather different way as well as we compare them to a silicone based reference.…”