Interpenetration control/blocking

Ideally, a simultaneous interpenetrating network should have extensive mixing at the molecular level, even to the extent of forming one uniform phase. As with other polymer blends, blocks, and grafts, SIN s exhibit phase separation attributed to the low entropy of mixing of two polymers which limits interpenetration in the real case. Thus there is an apparent discrepancy between theory and practice however, the pursuit of the ideal has led to a new understanding of the ways that super-molecular structure can be controlled, and new understanding of the relationship between polymer structure and properties. 

The second part, Chapters 2-9, is concerned with polymer blends, including mechanical blends, graft copolymers, block copolymers, ionomers, and interpenetrating polymer networks. The development of most chapters proceeds from synthesis to morphology, and then shows how morphology affects or controls the physical and mechanical behavior of the finished material. The most exciting development of the past decade, the electron microscope studies of the details of phase separation, is emphasized. 

A polymer mixture forms domains to give a dispersion of particles in a polymer matrix or a mixture of domains which are partly interpenetrated with each other. The control of size of particle or domain is an important item. A block copolymer is widely used as a compatibilizer for a polymer blend to obtain good dispersion. 

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