3D multiscale modeling to predict the elastic modulus of polymer/nanoclay composites considering realistic interphase property

Abstract

The elastic modulus of a nanocomposite reinforced with nanoclay was studied using the 3D finite-element method. It is widely accepted that interphase between nanoparticle and matrix plays an important role in the performance of the nanocomposite. Thus, a representative volume element (RVE) consisted of three phases (i.e. matrix, interphase and nanoclay) was simulated. In addition, to have a realistic estimation of elastic modulus of the interphase region, the modulus was computed using the available analytical formula. Since the nanoclays have been known as platelets and to investigate the effect of the third dimension, the nanoclay was simulated as a thin cuboid. The effect of various geometrical parameters, such as the change of the nanoclay contact area at a constant volume fraction of nanoclay, the variation of the nanoclay angle in the planes perpendicular and parallel to the loading direction, and the RVE dimensions, on the elastic modulus of a nanocomposite was considered. The results revealed that the increase in contact area of the nanoclay at a constant volume of nanoclay led to an increase in the elastic modulus of the nanocomposite. Furthermore, the change in the angle of nanoclay with respect to the plane parallel to loading direction has considerable effects on the elastic modulus of the nanocomposite, whereas this effect is negligible for the alignment angle perpendicular to the plane of the loading direction. Finally, unlike the previous studies, the results of the finite-element modeling were compared with three-phase theory of Mori–Tanaka.