Phosphonitrilic Compounds. VII. High Molecular Weight Poly(diaminophosphazenes)

High molecular weight poly(dichlorophosphazene), (NPCl₂)n, was allowed to react with aniline, dimethylamine, ethylamine, and piperidine to yield poly(diaminophosphazenes), [NP(NRRʹ)₂]n- The characterization and properties of these polymers are described. Reaction of (NPC1₂)n with ammonia or methylamine induced cross-linking of the phosphazene chains, while treatment with diethylamine, methylphenylamine, or diphenylamine did not bring about substitution. An explanation of this behavior in terms of steric hindrance involving the amine is discussed.- The qualitative results are consistent with the concept that replacement of chloro by amino in polyphosphazenes involves a nucleophilic attack by the amine at phosphorus. The poly(diaminophosphazenes) act as polyelectrolytes in acidic media.