Plasma-Initiated Polymerization of Chlorophosphazene and Organophospbazene Crystals

Abstract

Hexachlorocyclotriphosphazene (PNCl₂) ₃ crystals were found to polymerize quite easily when exposed to a radio-frequency cold plasma. The polymerization takes place almost simultaneously with the plasma-exposure. The monomer conversion increased with the plasma power as well as the plasma duration. The product was a white, rubber-like material. The IR spectrum of the product showed that the polymer had a chain backbone with a -P=N- structure, indicating occurrence of the ring-opening polymerization. It was also found that postpolymerization took place at elevated temperature following a brief exposure (1-5min) of plasma onto the phosphazene crystals. Attempts to polymerize organophosphazenes by this plasma initiation technique failed to give any elastomeric products.