Abstract
The shear stress σ and normal stress difference ν3, the sum of the first and the second normal stress differences, were measured for a concentrated polystyrene solution in double‐step shear deformations: a shear strain γ1 was applied at time t=−t1, another shear strain γ2 was added at t=0, and the stresses were measured for t>0. When t1 and t were larger than a certain characteristic time τk, the observed results for σ and ν3 were in accord with the prediction of the tube‐model theory of Doi and Edwards for various combinations of γ1 and γ2. Here the characteristic time τk, previously determined from the strain‐dependent relaxation modulus, gives the measure of the equilibration time of the contour length of polymer chain. The results for t>τk≫t1 were well described with the phenomenological BKZ model. The success of this model for t>τk≫t1 can be accounted for with the concept of tube model.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
