Mechanics of dielectric polyamide/SiO2 nanocomposite coatings for cryogenic service in superconductor systems

The implementation of high-temperature superconducting (HTS) power transmission has the potential to revolutionize the efficiency of electrical grids and help unlock a fully electric transportation infrastructure. Realizing the benefits of HTS systems has been impeded by a lack of available dielectric insulation materials that can (1) withstand the extreme cryogenic operating environment of superconductors and (2) demonstrate low temperature processing that is compatible with existing superconductor manufacturing methods. In this study, a silicon dioxide reinforced polyamide (PA/SiO2) nanocomposite with exceptional thermal stability has been developed as a solid dielectric coating solution. Thermomechanical characterization of the fabricated nanocomposite is conducted to explore multi-scale material property relationships relevant to the sought applications. The multifunctionality of the processed nanocomposite is demonstrated by an improved thermomechanical performance for cryogenic conditions and low temperature processing without decrements in certain mechanical properties. Additional experiments to investigate the nanoparticle-polymer interfacial mechanics are discussed. Results obtained herein present a viable option to solve the material challenges impeding wider implementation of HTS power transmission.