Abstract
It has been reported that the stretch/orientation-induced reduction of friction (SORF) has the significant effect on polymer dynamics under fast elongational flows. Although the construction of SORF suggests some effects of the flow field, the earlier studies have made exclusively for uniaxial elongational flows. In this study, for the first time we examined the effect of SORF under equi-biaxial elongation by means of the primitive chain network simulation. As reported for uniaxial elongation, the simulation fairly captured the literature data for transient biaxial elongational viscosity for a polystyrene melt. On the pretext of the reproducibility, the simulation was performed up to large strains at which the viscosity exhibits steady state. The results showed that the effect of SORF is essentially insensitive to the difference of the flow field. As a consequence, the strain hardening behavior is similar to each other for uniaxial and biaxial deformations given that the strain rate is common with respect to the Rouse relaxation time.
