A novel dielectric elastomer by constructing dual-network structure of carbon nanotubes and rubber nanoparticles in dynamically vulcanized thermoplastic elastomer

Thermoplastic vulcanizates (TPVs), as a special class of high-performance thermoplastic elastomers (TPEs), consist of a high content (60-80 wt%) of crosslinked rubber particles as the dispersed phase and a low content of a thermoplastic as the matrix. In this study, inspired by the special microstructure of TPVs, we prepared carbon nanotubes (CNTs)/TPV dielectric elastomer composites with a high dielectric constant (k) and low dielectric loss by constructing a dual network formed by rubber and CNTs. The rubber network was formed by a high content of agglomerates of rubber nanoparticles in the TPVs, which simultaneously promoted the formation of a CNTs network at a low content of CNTs in the matrix, to increase the value of k, and hindered the direct connection of CNTs with one another, to decrease the dielectric loss. As a result, the CNTs/TPV composites simultaneously possessed a high value of k and low dielectric loss. Moreover, the elasticity of the composites was improved by the CNTs because of the nanosprings of CNTs. This study provides a new simple and effective strategy for preparing a high-performance dielectric elastomer with a high value of k, low dielectric loss, good mechanical properties, high elasticity, high processability and easy recyclability.