Comparison of Rheological Properties between DoS and Liquid Dropping Methods in Uniaxial Extensional Flow of Dilute Polymer Aqueous Solutions

The dependence of solution concentration on rheological properties such as relaxation time and elongational viscosity in the uniaxial extensional flow of low-viscosity dilute polymer (PEO) aqueous solutions were investigated by means of Dripping onto Substrate (DoS) and liquid dropping methods. The difference in the extensional rheology between DoS and liquid dropping methods is negligible under the present experimental and analytical conditions, but the difference in rheological properties becomes larger as increasing the solution concentration, since the blocking effect of filament stretching due to the substrate becomes larger.