In-situ synthesis of MXene/polyimide nanocomposite with enhanced thermal and high temperature tribological performance

Polyimide (PI) is well known for its excellent thermal stability and mechanical strength, but its limited thermal conductivity and tribological performance restrict broader applications under harsh conditions. In this work, Ti 3 C 2 T x MXene nanosheets were incorporated into a PI matrix via in-situ polymerization to fabricate high-performance Ti 3 C 2 T x /PI nanocomposites with uniform filler dispersion. The thermal conductivity of the composite reached 1.99 W m −1 K −1 at 20 wt% MXene loading—an increase of 123% over pure PI. The thermal degradation temperature at 10% weight loss (T d10 ) also improved from 577.6 °C to 587.0 °C. Additionally, both storage modulus (E s ) and glass transition temperature (T g ) increased, indicating improved rigidity and thermal resistance. Tribological tests at room temperature and 200 °C revealed that the addition of 5 wt% MXene effectively reduced the coefficient of friction (COF) by 6.52% and 5.37%, respectively. The wear rate was also significantly reduced—by 83.41% at room temperature and 39.66% at 200 °C. These enhancements are attributed to the formation of a continuous and robust transfer film composed of MXene, oxides, and friction-induced organic products. This work provides a promising route for high-performance PI-based composites with improved thermal and tribological functionalities.