Enhancing the strength of polypropylene fibers with carbon nanotubes

Abstract

Single-walled carbon nanotubes were added to two different grades of polypropylene to produce composites. The composites were then melt-spun into fibers, and the fibers were tested with both a conventional tensile pull tester and dynamic mechanical analysis. The changes in tensile properties were related to the grade of polypropylene used. In addition to fibers being made from the mixes, coarse extrudates (i.e., undrawn, gravity-spun filaments) were also produced. Density measurements on these extrudatesshowed that the addition of nanotubes increased the composite density in a highly nonlinear manner, which suggested interaction between the polypropylene and the carbon nanotubes.

3D RVE Models Able to Capture and Quantify the Dispersion, Agglomeration, and Orientation State of CNT in CNT/PP Nanocomposites

“…The stress decrease after yield corresponds to the intrinsic softening of the polymer. Similar behavior of CNT/PP fibers is reported elsewhere (Moore et al, 2004). The elongation at the break of the PP fiber is also higher than that of the bulk PP specimen (see Figure 4A), which is due to the higher degree of alignment of amorphous chains in case of fibers during tensile stretching.…”

“…It is noted that addition of CNT results in significant improvement in the tensile properties of the fibers and lower elongation at break. The modulus and the strength of CNT/PP fiber composites are approximately twice and eight times the modulus and strength of the bulk CNT/ PP composites, respectively, for the same CNT content that is attributed to the alignment of CNT and polymer chains along the applied load direction and the increased crystallinity of the polymers due to the addition of CNT (Moore et al, 2004). Similar trends have been observed when bulk PP specimens are compared to neat PP fiber, as a result of the orientation of polymer chains along the draw direction and the strain-induced crystallization within the amorphous region in case of the fibers (Dabrowska et al, 2015).…”

Mechanical Reinforcement of Polymers Using Carbon Nanotubes

“…[98] In both cases, increases in modulus were observed, with reinforcements of ∼ 179 and ∼ 285 GPa for the LMFR and HMFR PP, respectively. However, while increases in strength, toughness, and ductility were observed for the LMFR polymer, the opposite was true for the HMFR material.…”

Morphological features and melting behavior of nanocomposites based on isotactic polypropylene and multiwalled carbon nanotubes

“…There have been several studies regarding mechanical performance, 7,8 electrical properties, 9,10 and decomposition 11,12 of this polymeric system, although the experimental results fall short from theoretical predictions. It is also well known that the physical properties of polymers are intimately linked to the morphology, which is developed after thermal and mechanical treatments.…”