(348g) Exploration of the Unique Shear Behavior of Binary Blend

Authors: 
Bunchatheeravate, P., Vertex Pharmaceuticals
Bullard, J. W., Vertex Pharmaceuticals
Curtis, J. S., University of California Davis
Yang, J., University of California Davis
Previous efforts to employ simple mixing rules to predict the flow properties of multi-component systems revealed that in some instances, flow function (FFc) values determined for binary mixtures were lower than those of either of their components. The behavior of these systems could not be described using conventional mixing rules, which necessitate that the properties of a mixture be bound by the values of those same properties exhibited by its constitutive materials. Here we present flow measurements from a series of such systems, and generalize characteristic features of the shift in flow behavior across multiple examples. In annular shear cell measurements of these systems, the shear force necessary to fail the bulk material is greater than that of the individual materials. The interaction of the two components appears to hinder the flow behavior of the bulk material. This effect is observed to be heavily influenced by the relative size and shape of the two components in a given system. The results indicate an approach to understanding the basis of certain cases of the flow behavior of mixtures, and offer an experimental framework for further in silico studes through methods such as DEM.