Enhancement of fracture properties of polymer composites reinforced by carbon nanotubes: A molecular dynamics study

Molecular cross-linked models of pure epoxy matrix and carbon nanotubes reinforced epoxy composites with initial single edged crack are developed. Tensile processes are conducted by applying the constant strain method to examine the enhanced fracture behaviors of the epoxy composites by introduction of carbon nanotubes as reinforcements. The results showed that increases of 24.8% and 34.3% in the tensile strength and elongation at break of the carbon nanotubes/epoxy composites can be obtained. The J-integral expressions are derived and an increase of 35.7% in the energy release rate of the carbon nanotubes/epoxy composites is achieved. The mechanisms of the enhanced fracture properties and crack growth behaviors of the epoxy composites are explored and interpreted from an atomic view by monitoring the variations of the non-bond interaction energy and radius distribution function between carbon nanotubes and epoxy matrix. (C) 2017 Elsevier Ltd. All rights reserved.