Polymer and materials synthesis and properties .2. Hybrid phosphazene-organosilicon polymers .1. Background, rationale, and small-molecule model compound chemistry

Most of the polymers that have been synthesized and studied over the past 50 years are organic macromolecules. However, many advantages exist for the development of polymers with inorganic backbones. The first major class of inorganic backbone polymers to be developed widely were the poly(organosiloxanes) (silicones), and these now are the subject of broad industrial and fundamental interest. Polyphosphazenes are a relatively new class of inorganic backbone polymers which rival many organic systems in their molecular structural diversity and property variations. They constitute only the second group of inorganic-organic polymers to be developed extensively. An emerging field of research involves an attempt to create a new area of polymer science at the interface between these two subjects, by the synthesis of hybrid organo-phosphazene-organosilicon systems. This review is a summary of recent progress in this new field.