Viscoelastic modeling of extrudate swell of Acrylonitrile-Butadiene-Styrene/Clay nanocomposite

The aim of the present work was to predict the extrudate swelling behavior of organoclay containing Acrylonitrile- Butadiene-Styrene (ABS) nanocomposite. The modeling was performed on the basis of unconstrained recovery concept originally introduced by Tanner but employing Wagner viscoelastic model with generalized Wagner damping function which is believed to be capable of taking into account the effect of organoclay on viscoelastic properties of nanocomposite sample. This approach enabled us to evaluate the effect of organoclay on extrudate swell in terms of disentanglement kinetics and chain relaxation behavior. In our modeling, the effect of die entrance region on the extent of extrudate swelling was also considered. In order to evaluate the validity of our modeling, the extrudate swell was measured as a function of wall shear stress for samples varying in organoclay content. The results predicted from the model were found to be in relatively good agreement with the experimental results.