Primitive chain network simulations for elongational viscosity of bidisperse polystyrene melts

Background Due to the industrial significance, elongational viscosity of polymeric liquids has been widely investigated. In particular, strain hardening, which is the deviation of the elongational viscosity from the linear viscoelastic envelope, has been of industrial and scientific interest because polymeric liquids exhibiting strain hardening are suitable for processing technologies with elongational flow such as fiber spinning, film blowing, blow molding, foaming, etc. [1, 2]. Münstedt [3] measured the uniaxial viscosity for polystyrene melts to report that the strain hardening is intensified when the molecular weight distribution is broadened. Minegishi et al. [4] demonstrated that the small amount of long chain component added to the short chain matrix effectively enhances the strain hardening. Further, Nielsen et al. [5] performed the experiments for the bidispersed polystyrene melts that are mixture of long and short molecules with narrow molecular weight distribution for each. They showed that the steady state viscosity ηE(ε̇) is significantly larger than the Trouton’s viscosity 3η0 for the bidispersed samples. Abstract