Evaluation thermal degradation kinetics of ionic liquid assisted polyetheretherketone-multiwalled carbon nanotubes composites

The incorporation of multiwalled carbon nanotubes (MWCNT) into polyetheretherketone (PEEK) composites has emerged as a promising strategy for enhancing the thermomechanical characteristics of PEEK composite materials. This study investigates the thermal behavior and kinetics prediction of PEEK/MWCNT composites comprising different ionic liquids (ILs), namely 1-butyl-3-methylimidazolium hydrogen sulfate ([BMIM]HSO₄), 1-butyl-3-methylimidazolium acetate ([BMIM]Ac), 1-ethyl-3-methylimidazolium acetate ([EMIM]Ac) and 1-ethyl-3-methylimidazolium hydrogen sulfate ([EMIM]HSO₄). Three non-isothermal methods Coats-Redfern, Broido, and Horowitz-Metzger, were employed to model the thermal decomposition profiles of fabricated composites to calculate the activation energy. The highest decomposition temperature (580°C) was obtained for [BMIM]HSO₄-based PEEK/MWCNT composites. Moreover, a 3%–8% increase in the activation energy was obtained compared to PEEK/MWCNT manufactured without ILs. The Coats-Redfern model was superior to Broido and Horowitz-Metzger models in modeling the thermal degradation of developed composites, as evidenced from the higher value of the coefficient of determination (R² ≥ 0.9899). By determining the Root Mean Square Error (RMSE) and R² for the thermal degradation kinetics data, the artificial neural network (ANN) model was employed. The ANN model accurately predicted the mass loss curves, exhibiting R² ≥ 0.9815 for the designed model. These findings can assist in establishing an IL-assisted benign approach for PEEK/MWCNT/IL composites with superior thermal characteristics.