Thermal properties of non-covalently functionalized graphene nanosheets and carbon nanotubes for advanced composites

In this work, thermal analysis demonstrates that both graphene nanosheets (G) and carbon nanotubes (CNT) have been successfully modified by π-stacking interactions with a pyrene derivative (PY) to give the functionalized nanofillers G-PY and CNT-PY. Thermogravimetric (TGA) curves show that the noncovalent modification considerably improves the thermal stability of the unfunctionalized G of about 70°C, thus causing an increase in the composite oxidative thermostability since the evolution of CO2 shifts to higher values. Besides, pristine CNT are stable up to about 520°C and, at this temperature, the modified CNT-PY show a weight loss of about 10 wt% attributable to the pyrene degradation and corresponding to the amount of functional groups attached to CNT. This functionalization imparted an overall enhancement of the electrical, mechanical and rheological properties of the nanocomposites.