A molecular dynamics simulations study was performed on Thrower-Stone-Wales defected carbon nanotube/polypropylene composites. Degradation of the carbon nanotube and the improvement of the interfacial adhesion between the defected carbon nanotubes and polypropylene molecules, considering different carbon nanotubes with different numbers of Thrower-Stone-Wales defects, was identified. By embedding the carbon nanotubes into a polypropylene matrix, the effect of the Thrower-Stone-Wales defects on the transversely isotropic elastic stiffness of polymer composites was calculated by molecular dynamics simulations. Even if the Thrower-Stone-Wales defects degraded the elastic properties of the carbon nanotubes, the transverse Young’s modulus and the transverse and longitudinal shear moduli of the composites increase due to the stronger interfacial adhesion between the defected carbon nanotubes and matrix, whereas the longitudinal Young’s modulus of the composites decreased. To elucidate the improved interfacial load transfer between the carbon nanotubes and the matrix, random polymer chain crystallization onto the surface of carbon nanotubes was simulated. The simulation showed that polypropylene chains were wrapped more uniformly onto the surfaces of defected carbon nanotubes than onto the pristine carbon nanotube. The non-bond adhesion energy between the polypropylene chains and the defected carbon nanotubes was greater than that between the polypropylene chains and the pristine carbon nanotube.

Influence of Thrower-Stone-Wales Defects on the Interfacial Properties of Carbon Nanotube/Polypropylene Composites by a Molecular Dynamics Approach. S.Yang, S.Yu, M.Cho: Carbon, 2013, 55, 133-43