Flow and Morphology of Two-Component Systems

In Chapter 2, the criteria for phase separation and stability of morphological forms of assorted polymer blends have been reviewed. However, 

When k and X are large, the deformation will tend to be small. VanOene (1974) has estimated values of k for typical polymer melts subjected to a 

The second normal stress function ( 2) relates the stress tensor T ZZ in the direction of flow and the stress tensor T 00 at an angle normal to the plane defined by the direction of flow and the velocity gradient  

It is now of interest to predict under what conditions one will find spheres, ribbons, or fibers in a flowing composite melt. Several predictions can be made, based on equations (9.6) and (9.7), and on the requirement that jij 0 for a droplet to be thermodynamically stable. First, if ( 2)a ( 2)/ phase a will always form droplets (or fibers) in phase p. On the other hand, the converse is not true phase p can form droplets in phase a only if 

Molecular weight and distribution are important. Assuming that ( 2) is proportional to the steady-state shear compliance and that is given by 

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