Abstract
ABSTRACTSilicone elastomers have been heavily investigated as candidates for the flexible insulator material in dielectric elastomer transducers and are as such almost ideal candidates because of their inherent softness and compliance. However, silicone elastomers suffer from low dielectric permittivity. This shortcoming has been attempted optimized through different approaches during recent years. Material optimization with the sole purpose of increasing the dielectric permittivity may lead to the introduction of problematic phenomena such as premature electrical breakdown due to high leakage currents of the thin elastomer film. Within this work, electrical breakdown phenomena of various types of permittivity-enhanced silicone elastomers are investigated. Results showed that different types of polymer backbone chemistries lead to differences in electrical breakdown patterns, which were revealed through SEM imaging. This may pave the way towards a better understanding of electrical breakdown mechanisms of dielectric elastomers and potentially lead to materials with increased electrical breakdown strengths.
Highlights
Silicone elastomers are gaining more and more attention for dielectric elastomer applications, mainly due to their inherent reliability which arises from the covalently crosslinked silicone polymer chains
Results showed that different types of polymer backbone chemistries lead to differences in electrical breakdown patterns, which were revealed through scanning electron microscopy (SEM) imaging
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
Summary
Silicone elastomers are gaining more and more attention for dielectric elastomer applications, mainly due to their inherent reliability which arises from the covalently crosslinked silicone polymer chains. Voltage stabilization of silicone elastomers becomes a complex task because it is crucial that the elastomer remains insulating and without conductive zones that could lead to build up of space charge [29] This means, that synthetic approaches to incorporation of additives into the silicone polymer backbone are required and that the final polymer structure must be tailored in such a way that the microscopic phase separation favors voltage stabilization [18] rather than electrical conduction. The chloropropyl-functionalized elastomers are interesting candidates for dielectric elastomer transducers since their overall properties provide great figures of merit [5] This is mainly due to combination of low Young’s modulus, and relatively high dielectric permittivity and electrical breakdown strength, and due to very low dielectric losses. The TGA potentially provides a basis for evaluation of the energies of chemical degradation (i.e. bond cleavage) involved in the electrical breakdown process
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
