Poly(butylene succinate) (PBS) was grafted on the surface of TEMPO (2,2,6,6‐tetramethyl‐1‐piperidinyloxy) modified multi‐walled carbon nanotubes (MWCNTs) via a nitroxide radical coupling reaction. TEMPO functionalized MWCNTs (MWCNTs‐g‐TEMPO) were synthesized using the Cu(I)‐catalyzed azide/alkyne click chemistry approach and the covalent bond of the nitroxide moieties onto the MWCNTs was confirmed via electron paramagnetic resonance (EPR) spectroscopy. The PBS grafting on the sidewalls of MWCNTs was carried out in solution via peroxide‐induced formation of macroradicals and it was confirmed by EPR and attenuated total reflectance Fourier transform infrared analysis. Preliminary rheological and calorimetric analyses revealed that the grafting improves both the quality of stress transfer across the polymer − nanotube interface and the degree of dispersion of the filler, which also …