Elongational Deformation of Dilute Polymer Solutions in Filament Stretching Rheometer

摘要

We examined an elongational viscosity for dilute polymer solutions by a filament stretching rheometer. The two aqueous solutions of PAA (Polyacrylamide) with different concentrations were used as test fluids. An elongational force acting on liquid in stretch deformation was estimated by a pressure transducer. In images of liquid filament for 0.005wt%PAA solution, the asymmetry of diameter profile with respect to the midpoint of filament were appeared. It was found that the response of pressure to the elongational deformation was closely connected to the transition of filament configuration. However, developing the stretch deformation with time, the necking of filament occurred at a certain time. After the occurrence of filament necking, it was confirmed that the elongational viscosity suddenly increased.