Alignment of carbon nanotubes and reinforcing effects in nylon-6 polymer compositefibers

Abstract

Alignment of pristine carbon nanotubes (P-CNTs) and fluorinated carbon nanotubes(F-CNTs) in nylon-6 polymer composite fibers (PCFs) has been achieved using asingle-screw extrusion method. CNTs have been used as filler reinforcements toenhance the mechanical and thermal properties of nylon-6 composite fibers. Thecomposites were fabricated by dry mixing nylon-6 polymer powder with the CNTs asthe first step, then followed by the melt extrusion process of fiber materials in asingle-screw extruder. The extruded fibers were stretched to their maxima and stabilizedusing a godet set-up. Finally, fibers were wound on a Wayne filament windermachine and tested for their tensile and thermal properties. The tests have shown aremarkable change in mechanical and thermal properties of nylon-6 polymer fibers withthe addition of 0.5 wt% F-CNTs and 1.0 wt% of P-CNTs. To draw a comparisonbetween the improvements achieved, the same process has been repeated withneat nylon-6 polymer. As a result, tensile strength has been increased by 230%for PCFs made with 0.5% F-CNTs and 1% P-CNTs as additives. These fibershave been further characterized by DSC, Raman spectroscopy and SEM whichconfirm the alignment of CNTs and interfacial bonding to nylon-6 polymer matrix.