Predicting the Young's modulus of intercalated and exfoliated polymer/clay nanocomposites

The Halpin-Tsai equations were used for the composites with low level content of reinforcements, which contain lamellar shape, high modulus and high aspect ratio. These characteristics of reinforcements were taken into consideration to simplify the Halpin-Tsai equations. The effect of different parameters on the longitudinal Young's modulus of well aligned polymer/clay nanocomposites was investigated for both exfoliated and intercalated microstructures. It was shown that the applied simplification had negligible effect on the prediction of the Halpin-Tsai model. For the intercalated structures with a high number of platelets per stack (n), increase in the gallery spacing did not influence the predicted modulus values. In an intercalated structure, the surface area of a stack, as the interface of filler-matrix, is n times lower than that of the exfoliated state. By considering the effect of the degree of exfoliation in the proposed model, a new equation was developed to predict the modulus enhancement in the nanocomposites filled with Montmorillonite (MMT). The theoretical predictions were supported by the experimental results.