Dynamics of monodisperse linear entangled polymer melts in extensional flow: The effect of excluded-volume interactions

We present an extension of the Rouse-CCR tube model for linear entangled polymers, by incorporating interchain repulsive excluded-volume interactions, to interpret extensional viscosity data of narrow molecular weight distribution polystyrene melts in strong extensional flows. The expression for the stress tensor is also adapted to account for modifications of the effective tube diameter due to flow-induced chain stretch. Despite its simplicity, the resulting model correctly captures the extensional rheological behavior of linear entangled monodisperse polystyrene melts already published in the literature.