A new form of a Halpin–Tsai micromechanical model for characterizing the mechanical properties of carbon nanotube-reinforced polymer nanocomposites

In the present work, a new form of a Halpin–Tsai (H–T) micromechanical model is proposed to characterize the elastic modulus and tensile strength of carbon nanotube (CNT)-reinforced polymer nanocomposites. To this end, three critical factors, including random dispersion, non-straight shape and agglomerated state of the CNTs are appropriately incorporated into the H–T model. A comparison of the model predictions with some experiments on the CNT/polymer nanocomposites serves to verify the applicability of the proposed approach. It is found that the present predictions are in good agreement with the available experimental data. The results clearly reveal that for a more accurate prediction of the mechanical properties of the CNT/polymer nanocomposites, considering the random orientation, waviness and agglomeration of CNTs into the polymer matrix is critically essential. Also, some parametric studies are carried out to show the effects of volume fraction, non-straight shape, aspect ratio, mechanical characteristics and non-uniform dispersion of CNTs as well as matrix properties on the elastic modulus and tensile strength of CNT/polymer nanocomposites. The results reveal that it is necessary to eliminate the agglomeration and use the straight CNTs if the full potential of CNT reinforcement is to be realized.