Network of Phase-Lines fluctuating with frequency w'
(to see the activation of the phase-lines see my blog of January 2012)
At the end of “the Great Myths of Polymer Melt Rheology,
Part I: Comparison of Experiments and Current Theory” ( http://dx.doi.org/10.1080/00222340903275529)
I wrote:
“The Rouse’s or reptation models (de Gennes,
Doi-Edwards), based on such a spectrum of relaxation times, are probably
not describing at all the basic deformation process giving rise to
viscoelastic effects (shear-thinning, normal stresses, extensional flow and the numerous other
phenomena observed in non-linear deformation) at very high shear rate, or at
high amplitude of strain, causing melt yielding, melt fracture and astonishing memory
effects. The models’ shortcoming is probably deeply rooted in the
misunderstanding of the concept of chain entanglement, and of the entropy of the melt deformation
process. “
Like my grandmother used to tell: “don’t criticize unless you
have something else to say, and only say it when it is clear to you”.
The Great Myths of Rheology, Part III (accepted for
publication in 2012) is the proof that I listened to my grandmother. I waited
to publish until it became clear to me that the new views on polymer entropy of
deformation and on entanglement could address all the issues of viscoelasticity.
Of course, like a painting which is never going to be
finished, I still have work to do... Yet, here it is, ready for discussion.
