Stress relaxation in linear polymer solutions after stepwise decrease of shear rate

1987 ◽  
Vol 20 (1) ◽  
pp. 153-156 ◽  
Author(s):  
Yoshiaki Takahashi ◽  
Yoshinobu Isono ◽  
Ichiro Noda ◽  
Mitsuru Nagasawa
Keyword(s):  
Shear Rate ◽  
Stress Relaxation ◽  
Polymer Solutions ◽  
Linear Polymer

Surface-tension-driven breakup of viscoelastic liquid threads

1982 ◽  
Vol 120 ◽  
pp. 245-266 ◽  
Author(s):  
Simon L. Goren ◽  
Moshe Gottlieb
Keyword(s):  
Relaxation Time ◽  
Stress Relaxation ◽  
Polymer Solutions ◽  
Small Diameter ◽  
Shear Thinning ◽  
Prior History ◽  
Axial Tension ◽  
Dilute Polymer Solutions ◽  
Linearized Stability ◽  
Newtonian Liquids

A linearized stability analysis is carried out for the breakup of small-diameter liquid filaments of dilute polymer solutions into droplets. Oldroyd's 8-constant model expressed in a corotational reference frame is used as the rheological equation of state. The crucial idea in this theory is the recognition that the liquid may be subject to an unrelaxed axial tension due to its prior history. If the tension is zero, the present analysis predicts that jets of shear-thinning liquids are less stable than comparable jets of Newtonian liquids; this is in agreement with previous analyses. However, when the axial tension is not zero, and provided the stress relaxation time constant is sufficiently large, the new theory predicts that the axial elastic tension can be a significant stabilizing influence. With reasonable values for the tension and stress relaxation time the theory explains the great stability observed for jets of some shear- thinning, dilute polymer solutions. The theory explains why drops produced from jets of such liquids are larger than drops from corresponding Newtonian liquids. The theory also appears capable of explaining the sudden appearance of irregularly spaced bulges on jets after long distances of t,ravel with little amplification of disturbances.

Thermodynamic and Hydrodynamic Properties of Linear Polymer Solutions. II. Limiting Viscosity Number of Monodisperse Poly(α-methylstyrene)

1970 ◽  
Vol 3 (6) ◽  
pp. 787-794 ◽  
Author(s):  
I. Noda ◽  
K. Mizutani ◽  
T. Kato ◽  
T. Fujimoto ◽  
M. Nagasawa
Keyword(s):  
Polymer Solutions ◽  
Linear Polymer ◽  
Hydrodynamic Properties
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