Structure build‐up at rest in polymer nanocomposites: Flow reversal experiments |
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| Authors: | Hassan Eslami Miroslav Grmela Mosto Bousmina |
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| Institution: | 1. Center for Applied Research on Polymers and Composites (CREPEC), Ecole Polytechnique de Montreal, C.P.6079 suc. Centre‐ville, Montreal, H3C 3A7, Quebec, Canada;2. Canada Research Chair on Polymer Physics and Nanotechnology and Center for Applied Research on Polymers and Composites (CREPEC), Department of Chemical Engineering, Laval University, Ste‐Foy, G1K 7P4, Quebec, Canada;3. Hassan II Academy of Sciences and Technology, Rabat, Marocco |
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| Abstract: | Evolution of the microstructure as well as the shear stress and the normal stress difference of polymer/layered silicate nanocomposites prepared by melt mixing of polybutylene succinate‐co‐adipate] and organically modified montmorillonite are investigated in transient forward and reverse start‐up shear flows at different clay loading and different shear rates. Special attention is paid to the structure build‐up at rest and to the amplitude of the overshoots observed during the reverse start‐up test in the shear stress and the normal stress difference. The model that we have developed previously is used to suggest an explanation for the observed phenomena. The model is able to capture observed behavior of the shear stress in both forward and reverse start‐up flows. It fails, however, to predict experimentally observed overshoot in the normal stress difference. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1728–1741, 2009 |
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| Keywords: | clay nanocomposites rheology |
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