Effects of nanotube helical angle on mechanical properties of carbon nanotube reinforced polymer composites

Carbon nanotubes (CNTs) possess exceptional mechanical properties and are therefore suitable candidates for use as reinforcements in composite materials. The CNTs, however, form complicated shapes and do not usually appear as straight reinforcements when introduced in polymer matrices. This results in a decrease in nanotube effectiveness in enhancing the matrix mechanical properties. In this paper, theory of elasticity of anisotropic materials and finite element method (FEM) are used to investigate the effects of CNT helical angle on effective mechanical properties of nanocomposites. Helical nanotubes with different helical angles are modeled to investigate the effects of nanotube helical angle on nanocomposite effective mechanical properties. In addition, the results of models consisting of helical nanotubes are compared with the effective mechanical properties of nanocomposites reinforced with straight nanotubes. Ultimately, the effects of helical CNT volume fraction on nanocomposite longitudinal modulus are investigated.

► We consider CNT helical angle effects on nanocomposite mechanical properties.
► Straight nanotubes are more effective in increasing the matrix modulus in the longitudinal direction.
► Helical nanotubes are less efficient in strengthening the matrix in the longitudinal direction.
► Helical nanotubes reinforced the polymer also in the transverse direction.
► Nanocomposite longitudinal modulus increased linearly with helical CNT volume fraction.