Microstructure in an immiscible polymer blend consists of the size, shape, and orientation of the phases. Blends exhibit many interesting behaviors, including enhanced elasticity at small strains, drop-size hysteresis, enhanced shear thinning, and stress relaxation curves whose shapes are sensitive to deformation history. These behaviors are directly related to changes in the microstructure, which result from phase deformation, coalescence, retraction, and different types of breakup. These phenomena are reviewed, together with models that describe them. Rheological measurements can probe the microstructure because microstructure contributes directly to stress through interfacial tension. Rheo-optical experiments also provide important insights. Droplet theories explain most of the phenomena for Newtonian phases at low concentrations. Behaviors at high volume fractions or with strongly non-Newtonian phases are less well understood.

Microstructural evolution in polymer blends

Most polymer blends are immiscible and need to be compatibilized. The compatibilization must accomplish: (i) optimization of the interfacial tension; (ii) stabilize the morphology against high stresses during forming; and (iii) enhance adhesion between the phases in the solid state. Compatibilization is accomplished either by addition of a compatibilizer or by reactive processing. This review will focus on the three aspects: description of the interphase, compatibilization by addition and reactive compatibilization.

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Compatibilization of Polymer Blends

Microstructural evolution of viscoelastic emulsions stabilised by sodium caseinate and xanthan gum

A critical review and experimental comparison between different techniques for the determination of interfacial tension are presented for a model polymer pair. Five experimental methods were applie...

Critical Experimental Comparison between Five Techniques for the Determination of Interfacial Tension in Polymer Blends: Model System of Polystyrene/Polyamide-6

Co-continuous morphologies in polymer blends with SEBS block copolymers

Keywords: interfacial tension ; polymer blends ; ellipsoid retraction Reference LTC-ARTICLE-1997-011 URL: http://www3.interscience.wiley.com/cgi-bin/jhome/36698 Record created on 2006-06-26, modified on 2016-08-08

A. Luciani

Papers

Interfacial tension coefficient from the retraction of ellipsoidal drops