A novel interphase modeling to estimate the effective mechanical properties of GNP-reinforced polymer nanocomposites

The present work is aimed at interphase modelling by a 3-D analytical high fidelity generalized method of cell (HFGMC) micromechanical model to extract the elastic properties of the polymer nanocomposites reinforced graphene nanoplatelets (GNPs). As a new idea, the GNP and its surrounding interphase are modelled as inclusion into a representative volume element (RVE) of nanocomposite containing two phases including inclusion and polymer matrix. Two mostly real situations-encountered substantial aspects affecting the polymer nanocomposite material behavior including the GNP content and the GNP/polymer interphase region are modelled and effects of these aspects on the nanocomposite properties are taken into account. It is assumed that the stiffness of GNP/polymer matrix interphase region changes gradually in the range of GNP stiffness and the polymer matrix stiffness. The GNP is a transversely isotropic material and both polymer matrix and interphase region are considered elastic with isotropic behavior. To verify the presented micromechanical model, firstly, the results of the micromechanical model compared with the experimental data. At the second step, the effect of various parameters including GNP content, interphase region characterization containing the thickness and adhesion coefficient are studied. Generally, an excellent agreement is found between the result of the present model and available experiment with consideration of the graded interphase.