Micromechanical modeling of the biaxial behavior of strain-induced crystallizable polyethylene terephthalate-clay nanocomposites

The present work addresses the question of the quantitative prediction of the biaxial response of polymer–clay nanocomposites experiencing strain-induced crystallization. Polyethylene terephthalate is taken as material model to represent the continuous amorphous phase of nanocomposites. A continuum-based micromechanical model is developed to predict the combined effect of strain-induced phase transformation and nanocomposite structural characteristics on the overall elastic-viscoplastic response. Comparisons with available experimental data are presented to illustrate the capabilities of the model in relation to various loading parameters in terms of loading path, loading rate and loading temperature. The model is used to provide a better understanding of the relationship between nanocomposite structural characteristics, phase transformation, intrinsic properties and loading parameters.