Mechanical and thermal behavior of nanoclay based polymer nanocomposites using statistical homogenization approach

In the present study, the effects of nanoclay additives on the effective mechanical and thermal properties of polymer/nanoclay composites have been investigated using experimental and simulation analyzes. In this research, we propose the use of strong contrast statistical continuum theory to predict the effective elastic and thermal properties. To validate our modeling approach, we conducted experimental measurements of these properties for polyamide/nanoclay nanocomposites with concentrations of 1, 3 and 5 wt.% of nanoclay particles. Three-dimensional isotropic nanocomposite samples with randomly oriented monolayer nanoclays were computer generated and used to calculate the statistical correlation functions of the realized model. These correlation functions have been exploited to calculate effective thermal and elastic properties of the nanocomposite. The simulation results have shown that effective stiffness can be increased significantly with small amounts of particle concentration for the exfoliated clay monolayers. The predicted effective conductivity and elastic modulus have been compared to our experimental results. Effective thermal conductivity shows satisfactory agreement with experimental data. However, the predicted results for the elastic modulus overestimate the experimental data, which might be due to the increasing intercalated structure for high concentration of nanofiller and to anisotropic properties of the nanoclay. (C) 2011 Elsevier Ltd. All rights reserved.