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Nanda Mandagi
| Speaker: |
Nanda Mangdagi
|
| Date: |
Wednesday September 20, 2006
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| Title: |
Modeling the
linear viscoeleastic behavior of entangled linear and star polymer
systems (Master's Thesis Presentation)
|
Abstract
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In the
rheological research, it is well known that the viscoelastic properties
of polymers depend on their molecular architectures. The study of this
relationship between the viscoelastic properties of polymers and their
molecular architecture has become of interest for Dow. Nowadays, Dow is
focusing on the enhancement of the existing model for linear polymers
to branched ones. One step forward in this direction is performed by
considering the simplest branched polymers, the star polymers. This
presentation gives an overview of recent work in constructing a model
that is able to predict the linear viscoelastic behavior of entangled
linear and (symmetric or asymmetric) star polymer systems. The
presented model is adapted from existing models in literatures. The
relaxation model of the polymers is derived based on the tube model.
Different architectures of polymers contribute in the relaxation
process of the system in different ways. Depending on the architecture,
polymers can relax either by reptating or retracting. Numerical results
are compared with available experimental data obtained from the
literature, and good correspondence is found. Moreover, it will be
shown how the developed model can be used to analyze the long chain
branching effect in the rheological behavior for polycarbonate systems.
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