Polyester and multiwalled carbon nanotube composites: characterization, electrical conductivity and antibacterial activity

Poly(butylene terephthalate) (PBT) composites containing multiwalled carbon nanotubes (MWCNTs) were prepared using a melt‐blending process and used to examine the effects on the composite structure and properties of replacing PBT with acrylic acid‐grafted PBT (PBT‐g‐AA). PBT‐g‐AA and multihydroxyl‐functionalized MWCNTs (MWCNTs‐OH) were used to improve the compatibility and dispersibility of the MWCNTs within the PBT matrix. The composites were characterized morphologically using transmission electron microscopy, and chemically using Fourier transform infrared, solid‐state 13C NMR and UV‐visible absorption spectroscopy. The antibacterial and electrical conductivity properties of the composites were also evaluated. MWCNTs or MWCNTs‐OH enhanced the antibacterial activity and electrical conductivity of the PBT/MWCNT or PBT‐g‐AA/MWCNTs‐OH composites. The functionalized PBT‐g‐AA/MWCNTs‐OH composites showed markedly enhanced antibacterial properties and electrical conductivity due to the formation of ester bonds from the condensation of the carboxylic acid groups of PBT‐g‐AA with the hydroxyl groups of MWCNTs‐OH. The optimal proportion of MWCNTs‐OH in the composites was 1 wt%; in excess of this amount, the compatibility between the organic and inorganic phases was compromised.