Phase Diagrams in Polymer Blends Broad Definition

6 PHASE DIAGRAMS IN POLYMER BLENDS (BROAD DEFINITION) 

Section 4.3 delineated some of the basic notions of polymer blend phase diagrams. Principally due to the very small entropy of mixing and usually positive heats of mixing, two polymers will be immiscible unless some strong interaction such as hydrogen bonding exists between them. Since the number of mer-sized holes in a polymer depends on the interactions between the attractive forces and molecular motion of the polymer chains, lower critical solution temperatures are usually observed. 

Classical composition-temperature phase diagrams cannot, however, be obtained for block copolymers because the chain segments (blocks) are attached to each other. Hence the volume fraction and the molecular weights of the blocks cannot be independently varied. However, people use the term 

In a more detailed calculation the self-consistent mean field theory reduces the problem of calculating the interactions among polymer chains to that of a single noninteracting polymer chain placed in an external field self-consistent with the composition profiles (26). Again, the primary objective is to compute the free energy and polymer distribution functions near the order-disorder transition. 

Originally three main phase morphologies were known spheres, cylinders, and alternating lamellae see Section 4.3.9. More recently several other 

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