Analysis of Polymer Blends by Rheological Techniques

Abstract

There is a growing commercial and academic interest in polymer blends and alloys. For these materials, the properties depend strongly on the flow induced morphology and on the distribution of residual stresses. To optimize the pro cessing and properties, it is important to know both the melt rheology and the orientation of the dispersed phase. This presentation concentrates on the first aspect. It would be impossible to understand the rheology of polymer blends without comparing their behavior to that of simpler, better known systems: solution, emulsion, foam, suspension or even polymer composites. The follow ing themes are discussed here: influence of equilibrium thermodynamics on rheology of homologous or miscible blends; effects of stress, strain and composi tions on flow morphology; effects of the interphase; correlations between rheological functions; yield phenomena; and extrudate swell.