Processing and properties of surface-localized nanocomposites as functional materials for space applications

Thermoplastic polymers are a compelling class of materials for space exploration applications due to their versatile mechanical properties and compatibility with various processing methods, including additive manufacturing. However, their low electrical conductivity limits their use in critical space applications, such as electronic devices and static charge dissipation materials. While electrical conductivity can be introduced through various conductive nanomaterials, dispersion challenges and processing limitations often make implementation difficult. Melt infiltration offers an alternative method to functionalize thermoplastic components by forming highly loaded surface-localized nanocomposites (SLNCs), avoiding some processing constraints of conductive thermoplastic blends. In this work, we developed a process to control the formation of electrically conductive, mechanically robust SLNCs using chemically modified reduced graphene oxide (CMrGO) and a variety of thermoplastic substrates. Fabrication conditions were selected based on each substrate’s thermal characteristics (glass transition or melting transition) and SLNCs were processed at temperatures that allow for net shape retention of molded parts. The mechanical and electro-mechanical response of these SLNCs were measured under uniaxial tension. Micromechanical modeling was used to evaluate the reinforcement effectiveness of CMrGO in a variety of polymer chemistries. The SLNCs developed showed promising results as active and passive flexible conductors under lunar application stress conditions, including tension, flexion, and abrasion with lunar simulant. This work highlights a path to robust, functional polymer materials suitable for lunar exploration and other space applications.