Tribological properties of polyimide coating filled with carbon nanotube at elevated temperatures

This work mainly focuses on the development and characterization of polyimide (PI) based composite coatings filled with multi-walled carbon nanotubes (MWCNT) on a steel substrate. The tribological properties of PI/MWCNT composite coatings at different temperatures ranging from room temperature (RT) to 200 degrees C were investigated. Also, the influence of MWCNT and thermal & mechanical properties of PI composites coatings were measured. The addition of MWCNT could reduce the friction coefficient as well as wear volume at elevated temperatures. The PI/3MWCNT composites coatings show better wear-resistant properties as compared to other composites. Also, the PI/MWCNT composites showed improved mechanical properties such as micro-hardness and nanoindentation. Formation of an organic-inorganic structure due to the inclusion of MWCNT, enhance the mechanical properties and reduce the thermo-degradation of composites coatings. The glass transition temperature (T-g) of the PI/MWCNT composites was improved as the MWCNT content increases from 0.1 to 5 wt%.