Özet
Entangled polymer melts exhibit a variety of flow instabilities that limit production rates in industrial applications. We present both experimental and computational findings, using flow of monodisperse linear polystyrenes in a contraction-expansion geometry, which illustrate the formation and development of one such flow instability. This viscoelastic disturbance is observed at the slit outlet and subsequently produces large-scale fluid motions upstream. A numerical linear stability study using the molecular structure based Rolie-Poly model confirms the instability and identifies important parameters within the model, which gives physical insight into the underlying mechanism. Chain stretch was found to play a critical role in the instability mechanism, which partially explains the effectiveness of introducing a low-molecular weight tail into a polymer blend to increase its processability.
Orijinal dil | İngilizce |
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Makale numarası | 050801 |
Dergi | Physical Review E |
Hacim | 77 |
Basın numarası | 5 |
DOI'lar | |
Yayın durumu | Yayınlandı - 19 May 2008 |
Harici olarak yayınlandı | Evet |