Modeling the stiffness of polymer/layered silicate nanocomposites: More accurate predictions with consideration of exfoliation ratio as a function of filler content

A micromechanical model for prediction of the elastic modulus of polymer/layered silicate nanocomposites was developed based on the conventional Halpin-Tsai model. The model considers near realistic intercalated and exfoliated structures of nanocomposites. The dependence of exfoliation ratio (the ratio of exfoliated filler content to the total filler content) on the filler concentration has been studied from different viewpoints and an exfoliation ratio function has been proposed. The predictions of the proposed model with variable exfoliation ratio functions were compared with the predictions of the same model with constant exfoliation ratio and the predictions of the Halpin-Tsai model using experimentally obtained results. The results of the proposed model with variable exfoliation ratio functions are in very good agreement with experimental data, particularly taking their nonlinearities into account.