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The thermal stability and non-isothermal degradation kinetics of high-density polyethylene (HDPE)/multi-wall carbon nanotube (MWNT) nanocomposites were studied by thermogravimetric and derivative thermogravimetric analyses using multiple heating rates (5, 10, 15, 20°C min -1 ) under nitrogen gas atmosphere. A series of HDPE/MWNT composites of various vol% concentration of nanotubes were fabricated using melt mixing process. The morphology and nanostructure of prepared nanocomposites was examined by field emission scanning electron microscopy (FESEM). The kinetic parameters were evaluated using multiple heating rate-based four different ''model-free'' methods (viz., Kissinger, Friedman, Flynn-Wall-Ozawa, and Kissinger-Akhaira-Sunose) and single heating rate-based one ''model-fitting'' method (Tang approach), and 18 kinetic model equations were used. FESEM images confirmed that the dispersion and distribution of the MWNTs in the HDPE polymer matrix was homogeneous. The kinetic parameters [E a , A, n, and k (Arrhenius constant at 600°C)] for all the samples studied were calculated. The highest values of E a , A, and n were found for the composites filled with 0.25 vol% MWNTs. For various vol% concentrations of HDPE/ MWNT nanocomposites, the dependence of the apparent activation energy (E a ) on fractional conversion (a) showed two-stage decomposition process, within the conversion window (0.05 B a B 0.95). Invariant kinetic parameter method (IKP) has been employed for all investigated nanocomposite system. A linear dependence between ln(A i ) and E a,i was observed, making use of so-called compensation effect. Using IKP method, the values of the artificial isokinetic temperature ''T iso '' and artificial isokinetic rate constant ''k iso '' have been also estimated for all heating rates and found increases with increase in the heating rate (b). In addition, the dependence of lnA a on a was evaluated, and it was found that the lnA a revealed the same dependence on a as the apparent activation energies (E a ) versus a plot shown. In order to estimate the kinetic degradation mechanism(s) of investigated system, Criado method was employed. The thermal decomposition kinetics of HDPE/MWNT composites were found to be best described by kinetic equations of n th order (AnFn and Dn mechanisms) to be more precise A1F1 ? D1 ? D2 kinetic models.

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