The stress–strain behavior of polymer–nanotube composites from molecular dynamics simulation

Stress–strain curves of polymer–carbon nanotube composites generated from molecular dynamics simulations of a single-walled carbon nanotube embedded in polyethylene are presented. A comparison is made between the response to mechanical loading of a composite with a long, continuous nanotube (replicated via periodic boundary conditions) and the response of a composite with a short, discontinuous nanotube. Both composites are mechanically loaded in the direction of, and transverse to, the nanotube axis. The long-nanotube composite shows an increase in the stiffness relative to the polymer and behaves anisotropically under the different loading conditions considered. The short-nanotube composite shows no enhancement relative to the polymer, most probably because of its low aspect ratio. The stress–strain curves from molecular dynamics simulations are compared with corresponding rule-of-mixtures predictions.