Fabrication and Properties of Polyamide-6,6-functionalized Carboxylic Multi-walled Carbon Nanotube Composite Fibers.

Polyamide-6,6 (PA66)-functionalized carboxylic multi-walled carbon nanotubes (CMWNTs) were fabricated by in situ polymerization. The composite was melt-spun into fibers. The structures and properties of the PA66-functionalized multi-walled carbon nanotubes (PFNTs) were characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), etc. CMWNTs were seen to be uniformly scattered throughout the matrix. Aggregation of CMWNTs was not observed in the fracture surface of the composite fiber. The CMWNTs were not completely pulled out from the matrix, implying strong interactions as a result of functionalization. The incorporation of CMWNTs into PA66 did not have a significant effect on the thermal decomposition temperature of the composites. The effect of CMWNT was on the crystallographic form of the composite. The grain sizes of crystals increased as the CMWNT content increased. The storage modulus significantly increased with the increase in CMWNT content. The tensile strength and modulus of the fibers were significantly improved whereas the strain on the fiber decreased with the increased content of CMWNT. [ABSTRACT FROM PUBLISHER]