The improved viscoelastic properties of long‐length carbon nanotubes reinforced polyamide‐6 composites

Abstract The semi‐crystallinity, thermoplasticity, high toughness, and light weight of polyamide‐6 (PA6) when reinforced with carbon nanotubes (CNTs) provide outstanding physical properties to the nanocomposites by combining the physical properties of both components. The processing difficulties arising due to the high toughness and abrasion resistance of PA6 and the agglomeration of in‐house synthesized long‐length CNTs can be tackled by melt‐mixing the components inside a twin‐screw extruder with a back‐flow channel. The 0.1–7 parts per hundred ratios (phr) of CNTs reinforced PA6 composites were characterized for their viscoelastic properties through oscillatory rheometry and dynamic mechanical analysis (DMA) at fixed operating conditions. The outcomes showed continuous shiftings in storage and loss modulus values with increasing reinforcements along with a viscoelastic transition at 3 phr CNTs reinforcements observed in DMA. A 19°C rise in glass transition temperature (T_g) was observed in DMA with 0.1 phr CNTs reinforcement, which showed further improvements with increasing CNTs content. The interactions among PA6 and CNTs were further confirmed by X‐ray diffraction (XRD) and Raman spectroscopy curves. These nanocomposites promise mechanical applications in the equipments of automobiles, aerospace, defense, biomedical, bio‐sensors, etc. Highlights Viscoelastic properties study for CNTs/PA6 composites Uniform intermixing of CNTs within PA6 via extrusion with back‐flow channel Detailed analysis of rheometry and DMA of the composites CNTs‐PA6 interactions estimated from rising intensity peaks in Raman spectra and X‐ray diffraction (XRD) Potential candidates for components in automobiles, aircraft, biomedicals, and sports industry