SYNTHESIS OF POLYPHOSPHAZENES FROM PHOSPHORANIMINES AND PHOSPHINE AZIDES

A number of phosphoranimines were prepared via the Staudinger coupling of the suitably substituted phosphite with trimethylsilyl azide. Thes e compounds were polymerized under various conditions using fluoride i nitiators and then characterized by H-1 and P-31 nuclear magnetic reso nance, size exclusion chromatography vel sus polystyrene standards, an d differential scanning calorimetry. The condensation by-products of t he polymerization were analysed by gas chromatography-mass spectrometr y. Mechanistic details of these polymerizations are also discussed. N- Blocked phosphoranimines were prepared and used as chain terminators t o control the molecular weights of these polymers. Several random copo lymers were produced by the simultaneous polymerization of two phospho ranimines, and the first reported block copolymers were synthesized by the homopolymerization of one monomer followed by the subsequent addi tion of a second. The synthesis of the first soluble aryl-substituted polyphosphazenes via the phosphine azide route is also discussed.