Role of interface bonding on the elastic properties of epoxy-based nanocomposites with carbon nanotubes using multiscale analysis

The interface bonding between filler and matrix governs the elastic properties of the overall polymer/nanotube nanocomposites and is generally difficult to model. In this work, a cohesive law based on the Lennard-Jones potential was established to describe the van der Waals interactions at the nanotube-polymer interface. The elastic properties of epoxy (RTM6-2)/SWCNT nanocomposites were evaluated through 3D multiscale finite element model of the representative volume element (RVE) of the nanocomposites with imperfect polymer-matrix interface and nanotube-nanotube interactions based on van der Waals force. We evaluated the effect of interface debonding on the elastic properties of the nanocomposites for different values of SWCNT loading and aspect ratio, and compared the results with the case of perfect bonding between polymer and matrix. Results show that the presence of the interface generates significantly lower elastic properties than in the case of perfect bonding due to the decohesion effect, which reduces the load transfer between matrix and filler, such as in real nanocomposite systems.