Development of Hashin-Shtrikman model to determine the roles and properties of interphases in clay/CaCO₃/PP ternary nanocomposite

The Hashin-Shtrikman model underpredicts the bulk, shear and Young's moduli of the prepared clay/CaCO₃/PP ternary polymer nanocomposite (TPN) by ignoring the interphase between polymer matrix and nanoparticles. In this study, the Hashin-Shtrikman model was developed assuming the thickness and strength of interphases. Also, the thickness and strength of interphases in the ternary samples could be calculated by the developed Hashin-Shtrikman and Pukanszky models, respectively using the experimental results of mechanical properties. The predictions of the developed model showed good agreement with the experimental data at different Mt and CaCO₃ contents assuming the interphase role which validate the current approach. According to the calculations, the strong and thick interphases were formed in the TPN at low nanofiller concentrations. This occurrence for the present samples was explained by the material and processing parameters. However, the thickness and strength of interphases weakened by increasing in clay content, probably due to the poor dispersion of nanoparticles and reduced interfacial area/adhesion at this condition.