Extensional rheometry of model liquids: Simulations of filament stretching

Polymeric liquid bridges are known to fail during extension. This phenomenon of failure seemingly calls into question the operating principle filament stretching rheometers. In these devices, a polymeric sample is initially placed between two plates. The then stretched bridge by moving plates apart in specified way. We here show that steady extensional viscosity can be measured if separated such way stretch rate symmetry plane kept constant, even for liquids highly prone instability. Moreover, reliable measurements stress relaxation phase obtained as well. conclusions based on simulations number constitutive equations, including Newtonian liquid, Oldroyd-B model, differential non-stretch Rolie–Poly and integral Doi–Edwards model with without associated dynamics.