Highly Stretchable Poly(thiocarbonate)/Graphene Oxide Dielectric Composites toward a High Dielectric Constant and Low Dielectric Loss

Dielectric elastomers (DEs) have attracted much attention due to their application prospects in biomimetic actuated devices, it is still a big challenge to prepare DEs with high dielectric constants (ε′) and low dielectric losses (tan δ). This work reports highly stretchable poly(propylene-monothiocarbonate)/graphene oxide (PPMTC/GO) dielectric composites with high ε′ and low tan δ via a simple solution-mixing process. The PPMTC with repeated thiocarbonate units enhances the interfacial polarizations with GO, leading to a high ε′ (up to 12). Meanwhile, the hydrogen bonding interactions of PPMTC and GO improve the dispersion of GO in the polymer matrix and thus decrease tan δ (∼0.07). Interestingly, the PPMTC/GO composites also possess excellent shape-memory performance, especially under large deformations (about 50%), with both the fixing ratio (Rf) and recovery ratio (Rr) more than 90%. In addition, the ultimate tensile strength is about 6.5 MPa for the neat PPMTC and over 7.0 MPa for its composites, and the elongation at break for all the samples is over 700%. Thus, it provides an alternative method to the fabrication of DEs.