Elastic Properties of Randomly Dispersed Functionalized Silicon Carbide Nanotubes/Polymer Nanocomposites: Combined Multiscale Molecular Dynamics and Finite Element Modeling

A molecular dynamics (MD)-finite element (FE) modeling scheme is proposed to study the effective Young's modulus of polymer nanocomposites reinforced by functionalized silicon carbide nanotubes (fSiCNTs). By evaluating the tensile and shear properties of the polymer matrix strengthened by hydroxyl (O-H)-, fluorine (F)-, and hydrogen (H)-fSiCNTs (O-, F-, and H-fSiCNT/ polymer) through MD simulations, FE modeling with the consideration of equivalent solid fibers (ESFs) is conducted and the ratio of effective Young's modulus of the unit cell ( E UC) to Young's modulus of the polymer matrix ( E P) is reported. The influence of the chirality, and chemical functionalization of nanotubes along with the effects of the volume fraction of the ESFs, and polymer materials on the E UC are discovered. The results show that the random dispersion of ESFs containing armchair fSiCNTs (ESFs-armchair fSiCNTs) within the polymers (ESFs-armchair fSiCNTs/polymer) instead of the ESFs-pure armchair fSiCNTs leads to reducing the E UC. In every ESFs volume fraction (. f), the reinforcement impact of the ESFs- armchair and zigzag fSiCNTs on the polyethylene (PE) is more significant in comparison with the polypropylene (PP). Using the ESFs-zigzag H- and F-fSiCNTs/PP instead of the ESFs-pure zigzag SiCNTs/PP decreases E UC E P, while at the ESFs'. f over 10%, the E UCE P of the ESFs-zigzag O-fSiCNTs/PP is higher than that of the ESFs-pure zigzag SiCNTs/PP. The ESFs-zigzag H- and F-fSiCNTs/PE as compared to the ESFs-pure zigzag SiCNTs/PE are experienced larger effective elastic moduli, however, only at the ESFs'. f of 50%, the reinforcing impact of the ESFs-zigzag O-fSiCNTs within the PE is more considerable than that of the ESFs-pure zigzag SiCNTs.