Effect of multi-walled carbon nanotubes on morphology, mechanical and thermal properties of poly(ethylene terephthalate) nanocomposites

Poly (ethylene terephthalate)/modified multi-walled carbon nanotubes (PET/c-MWCNTs) nanocomposites with different c-MWCNTs loadings were prepared by melt compounding in a twin-screw extruder. The influence of the addition of c-MWCNTs on the morphology, mechanical and thermal properties of the nanocomposites was investigated. From scanning electronic microscopy (SEM) images of nanocomposites, it can be clearly seen that the PET/c-MWCNTs nanocomposites with low c-MWCNTs contents (0.25 and 0.50wt%) get better c-MWCNTs dispersion than analogous with high-tube loading (1wt%). Mechanical testing shows that in comparison with neat PET, the tensile modulus and the stress at break of the PET nanocomposites with incorporating 0.5wt% c-MWCNTs are effectively improved by about 15% and 63%, respectively. The presence of c-MWCNTs, which acted as good nucleating agents, enhanced the crystallization of PET through heterogeneous nucleation. The incorporation of a small quantity of c-MWCNTs improved the thermal stability of the PET/c-MWCNT nanocomposites.