Interpenetrating polymer networks

Interpenetrating polymer networks (IPNs) composed of two or more chemically distinct networks are not only intrinsically interesting as examples of macromolecular chemical topological isomerism but are in practice useful means of controlling mutual miscibility and phase morphology in crosslinked polymers. We will first review briefly the synthesis and properties of such IPN systems. This will be followed by an outline of a phenomenological theory of the phase stability and linearised theory of spinodal decomposition of binary, chemically quenched, low crosslink density IPNs recently developed by K. Binder and the author. Finally, we will discuss some aspects of the synthesis of ternary IPNs and the thermochromic properties of IPNs containing a crosslinked polydiacetylene.