ABSTRACT
Polyphosphazenes are unique in the field of polymer synthesis, since, in theory, an infinite number of polymers having various properties may be derived from a common polymeric intermediate, polydichlorophosphazene, designated by the structure (PNCh)n, by replacing the chlorines with different organic nucleophiles. If a polydichlorophosphazene precursor is reacted with the sodium salts of trifluoroethanol and a mixed fluorotelomer alcohol, a polyfluoroalkoxyphosphazene elastomer, referred to hereafter by the generic designation FZ (as per ASTM D1418), is obtained that has a unique set of properties including a wide service-temperature range (- 65 to 175°C), fuel and oil resistance, and excellent flex fatigue and damping characteristics. Replacement of the chlorine atoms of the polydichlorophosphazene with phenoxy and p-ethylphenoxy groups yields a polyaryloxyphosphazene, hereafter referred to by the generic designation PZ (as per ASTM D 1418), a nonhalogenated, flame-resistant, low-smoke-producing elastomer suitable for use as wire and cable insulation and insulating foams.
