Modeling of Stiffening and Strengthening in Nano-Layered Silicate/Epoxy

The aim of this paper is to investigate adhesion property between nano-layered filler and the polymer matrix using a combination of experimental and micromechanical models as well as the changes in yield strength and stiffness of a layered silicate-filled epoxy nanocomposite. The results indicate that addition of intercalated layered silicate particles increased Young’s modulus and yield strength of the epoxy resin, although the increases in stiffness and yield strength are modest, 30% and 4%, respectively. In addition, experimental results were compared with predictive stiffening and strengthening models. The rule of mixtures provides an upper bound for the modulus in these materials, while the Halpin-Tsai model provides a lower bound at low filler contents. The strengthening model used suggests the possibility of presence of a relatively modest adhesion between the intercalated layered silicate and epoxy resin rather than weak adhesion in the intercalated systems.