Permanent link: http://hdl.handle.net/1959.3/62785
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- Title
- Rheology of hyperbranched polymer melts undergoing planar Couette flow
- Author(s)
- Le, T. C.; Todd, B. D.; Daivis, Peter J.; Uhlherr, Alfred
- Abstract
- The melt rheology of four hyperbranched polymer structures with different molecular weights has been studied using nonequilibrium molecular dynamics (NEMD). Systems were simulated over a wide range of strain rates to capture the crossover behavior from Newtonian to non-Newtonian regimes. Rheological properties including shear viscosity and first and second normal stress coefficients were computed and the transition to shear thinning was observed at different strain rates for hyperbranched polymers of different sizes. The results were consistent with previous findings from NEMD simulation of linear and dendritic polymers. Flow birefringence was characterized by taking into account both form and intrinsic birefringences, which result from molecular and bond alignment, respectively. The stress optical rule was tested and shown to be valid only in the Newtonian regime and violated in the strong flow regime where the rule does not take into account flow-induced changes of the microstructure.
- Publication Type
- Journal article
- Research Centre
- Swinburne University of Technology. Faculty of Information and Communication Technologies. Centre for Molecular Simulation
- Source
- Journal of Chemical Physics, Vol. 131, no. 4 (Jul 2009)
- Publication Year
- 2009
- FOR Code(s)
- 0202 Atomic, Molecular, Nuclear, Particle and Plasma Physics; 0306 Physical Chemistry (Incl. Structural)
- Keyword(s)
- Birefringence; Couette flow; Flow simulation; Molecular dynamics; Polymer melts; Rheology
- Publisher
- American Institute of Physics
- Publisher URL
- http://dx.doi.org/10.1063/1.3184799
- Copyright
- Copyright © 2009 American Institute of Physics. Published version of this paper reproduced here in accordance with the copyright policy of the publisher.
- ISSN
- 0021-9606
- Full Text
- Peer Reviewed
