Bicomponent melt spinning of polyamide 6/carbon nanotube/carbon black filaments: Investigation of effect of melt mass-flow rate on electrical conductivity

Combining the several mixed phase structures and property profiles with a conductive, high aspect ratios nanofiller such as carbon nanotubes, graphene, and carbon black, specific morphological structures in melt spinning can be reached that offer much more potential for developing new functional fibers. Thus, understanding and controlling filler localization inside the developing phase morphology during melt spinning are the keys to the necessary structures. This work aimed to offer the possibility of producing fibers from electrically conductive polymer composites with a high filler concentration. First, the influence of different commercially available nanofillers, such as multi-wall carbon nanotubes (MWCNTs), graphene and carbon black on Polyamide 6 (PA6)-based nanocomposite melt-spun fibers were examined. Following the lab-scale melt spinning experiments, PA6/MWCNT-CB nanocomposite filaments containing 10 wt% nanofiller (each 5 wt%), were chosen for a pilot-scale bicomponent melt spinning process to investigate the influence of the nanocomposite core material feeding parameters on the properties of melt-spun fibers. The electrical conductivity decreased by half (from 3.13E-02 to 6.72E-03) when melt flow rate was increased from 3 g/min to 6 g/min. Scanning electron microscopy micrographs and thermal gravimetric analysis thermograms showed that the change in MFR values significantly affected the nanocomposite filaments’ surface properties.