Etude rheologique sur de suspensions concentrees de latex de poly(styrene-butadiene)

The main objective of this project was to characterize the rheological behavior of latex suspensions. We used oscillatory tests, along with the continuous shear tests to obtain information about the steady shear viscosity and the concentration of electrolyte. The ionic strength was varied in order to modify the electrical interparticle forces. As second objective, the rheological results were interpreted in the view of the DLVO theory (Derjaguin, Landau, Vervey and Overbeek). Finally, the third objective was to use the structural model proposed by Yziquel et al. (1999) for predicting the rheological behavior of the studied systems.;We were interested in this work to observe the rheology of suspensions made of particles that present repulsive interactions, other than the hydrodynamic forces, but that can still be considered as model particles. For the simplest suspension, the particle shape must not influence the rheology and the suspending medium must be Newtonian. We considered therefore spherical particles into a medium with almost the same density as the particles, to avoid sedimentation or flotation problems. The suspension chosen consists of colloidal latex particles of poly(styrene-butadiene) in water. (Abstract shortened by UMI.)...