To What Extent Can Hyperelastic Models Make Sense the Effect of Clay Surface Treatment on the Mechanical Properties of Elastomeric Nanocomposites?

The poor knowledge about nonlinear mechanical behavior of elastomer nanocomposites arises from the incomplete information on the interface. Application of hyperelastic models provides more insights into the nature and the situation of interaction between the elastomeric matrix and nanofillers. The current work seeks to address the effect of interphase strength on tensile properties of the elastomer nanocomposites under large deformations. Acrylonitrile butadiene rubber (NBR)/clay nanocomposite is selected for modeling on account of complexities associated with exfoliation/intercalation of clay platelets. In particular, it is aimed to specify to what extent hyperelastic models can capture the effect of clay surface functionalization on the mechanical behavior of nanocomposites. Attachment of silane functional groups to the clay surface is confirmed by Fourier transform infrared spectroscopy, wide-angle X-ray diffraction, and thermogravimetric analyses. Different hyperelastic models are examined to detect the characteristic of NBR/clay nanocomposites. The powerfulness/weakness of the used models are featured by calculating the strain energy functions and material parameters, meanwhile, by comparing model outputs with experimental data of tensile tests.