Mechanical behavior of a PP platelet-reinforced nanocomposite: Experimental characterization and two scale modeling of linear and non-linear response

The present study is devoted to the mechanical behavior of a class of nanocomposites made up of polypropylene reinforced by montmorillonite clay nanoplatelets. We first performed uniaxial tensile tests which shown that some mechanical characteristics (Young's modulus, yield stress) of the nanocomposite significantly increase compared to the matrix, even for very low volume fraction (less than 3%). For the elastic regime, it is shown that the Ponte Castañeda and Willis (PCW) bound predicts accurately the impact of nanoplatelets on the moduli, provided that a suitable choice of the aspect ratio is made. The non-linear behavior of the nanocomposites is investigated by means of Hill-type incremental homogenization method combined with PCW bound. Finally, the model predictions are compared to our experimental data.