Multiwalled-carbon nanotubes/poly (butylene terephthalate) nanofibres: Morphological, mechanical and thermal properties

Poly(butylene terephthalate) (PBT) nanofibres containing functionalized multiwalled-carbon nanotubes (F-MWNTs) were prepared by electrospinning technique. The F-MWNTs were prepared by the introduction of aromatic amine (COC₆H₄-NH₂) groups onto their side wall via Friedel-Crafts acylation. The diameter of neat PBT nanofibres was below 500 nm and had smooth surface. The scanning electron microscopy (SEM) also showed that F-MWNTs/PBT composite nanofibres mat had similar morphology with that of pure PBT and without beads. The surface of the composite nanofibres was also smooth even by adding high quantity of F-MWNTs. The F-MWNTs were embedded within nanofibres and well oriented along the nanofibre axis, as confirmed by transmission electron microscopy (TEM). The mechanical properties (specific tensile strength and moduli) of the PBT nanofibres were significantly enhanced by the incorporation of F-MWNTs. It was also observed that the melt-crystallization temperature (T_c) of PBT nanofibres shifted to a higher temperature (about 10°C) by the incorporation of F-MWNTs which might be due to the nucleating effect of the nanotubes.