Facile fabrication of high-performance PA66/MWNT nanocomposite fibers

Carbon nanotubes (CNTs) are promising polymer-strengthening materials; however, it is difficult to achieve the even distribution of CNTs in polymer matrixes and strong interfacial interactions between CNTs and polymeric chains. In the present work, multi-walled carbon nanotubes (MWNTs), carboxylic multi-walled carbon nanotubes (MWNTs-COOH), amino multi-walled carbon nanotubes (MWNTs-NH2), and hydroxylated multi-walled carbon nanotubes (MWNTs-OH) were added as reinforcements to the polyamide 66 (PA66) matrix. CNTs were dispersed in the PA66 matrix by a twin-rotor high-speed mixing extruder at 800 rpm. Chips were melted spun and two-step stretched to fabricate nanocomposite fibers. The microstructure and properties of nanocomposite fibers were investigated. It was found that MWNTs-COOH were well dispersed in the PA66 matrix. PA66/MWNTs-COOH nanocomposite fibers exhibited the best mechanical properties. The tensile strength and Young’s modulus of PA66/0.3 wt% MWNTs-COOH nanocomposite fibers were ~ 907 MPa and ~ 5.92 GPa, respectively, which were 22.2% and 4.8% higher than those of pure PA66 fibers, respectively.