Abstract
The startup of uni-axial elongational flow followed by stress relaxation and reversed bi-axial flow has been measured for a branched polystyrene melt with narrow molar mass distribution using the filament stretching rheometer. The branched polystyrene melt was a multiarm A(q)-C-C-A(q) pom-pom polystyrene with an estimated average number of arms of q=2.5. The molar mass of each arm is about 28 kg/mole with an overall molar mass of M-w=280 kg/mole. An integral molecular stress function constitutive formulation within the "interchain pressure" concept agrees reasonably well with the experiments.
Original language | English |
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Journal | Journal of Rheology |
Volume | 53 |
Issue number | 2 |
Pages (from-to) | 401-415 |
ISSN | 0148-6055 |
DOIs | |
Publication status | Published - 2009 |
Bibliographical note
Copyright (2009) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.Keywords
- polymer melts
- non-Newtonian flow
- rheology
- plastic flow
- elongation