Influence of the spinning conditions on the structure and properties of polyamide 12/carbon nanotube composite fibers

The inclusion of nanoparticles in polymer fibers is potentially useful for improving or bringing new properties such as mechanical strength, electrical conductivity, piezoresistivity, and flame retardancy. In this study, composite fibers made of polyamide 12 and multiwall carbon nanotubes were investigated. The fibers were spun via a melt-spinning process and stretched at different draw ratios. The influence of several spinning factors, including spinning speed, extrusion rate, and draw ratio were investigated and correlated to the structure and properties of the fibers. X-ray diffraction analyses and mechanical tests indicated that the spinning speed barely affected the structure and mechanical properties of the fibers under tension. The spinning speed, however, is critical for future industrial applications because it determines the possible production rates. By contrast, drawing during spinning or after spinning strongly affected the polymer chain alignment and fiber mechanical properties.