New developments in the science and applications of polyphosphazenes

Polyphosphazenes constitute the largest class of inorganic-organic polymers. They fall into three categories: open chain polymers; polymers in which small phosphazene rings are linked to an organic polymer chain; and cyclomatrix materials in which phosphazene rings are connected two each other to form a three-dimensional matrix. Recently, a new synthetic route to the polymers within the first category was developed which involves an ambient temperature living cationic condensation of phosphoranimines. In addition, the ring opening metathesis reaction has also been utilized for the preparation of polymers of within second category. Both these approaches widens considerably the opportunities to develop new phosphazenes and additional uses.