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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A tube based configuration formalism for entangled linear polymers under flow

Leygue, Adrien 05 July 2005 (has links)
In this thesis, we propose a new microstructural model to describe the rheology of entangled linear polymers. In order to reduce the number of non-linear adjustable parameters, we develop a model capable of predicting both the linear and the non-linear response, using a single set of material parameters. In a first step, a linear differential formulation of the thermal constraint release mechanism is introduced and validated against experimental results for linear polystyrene melts. In a second step, we extend the linear model to the non-linear regime by generalizing the state variables to conformation tensors and accounting for the relevant non-linear relaxation phenomena. The numerical predictions of the resulting model are then compared to experimental data for entangled polymer melts and solutions in different flow regimes. Finally, we show, on a simple reptation model, how the single generator bracket formalism of non-equilibrium thermodynamics can be used for the phenomenological improvement of microstructural constitutive models.
2

Extensional Behavior of Entangled Polymers

Wang, Yangyang 03 December 2010 (has links)
No description available.

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