Synthesis of N,N′-bis [(dialkoxyphosphinyl) methyl]-1,4-benzenediamines and the corresponding polymers

The title diamines were synthesized by condensation of 1,4-phenylenediamine with paraformaldehyde and a suitable phosphorus acid triester. The N,N′-dibenzoyl derivatives of the above compounds were also prepared. New flame-retardant polyamides were synthesized under various experimental conditions by condensation of these diamines with terephthaloyl dichloride. The polyamides produced have low viscosities. Blends with polystyrene (PS) have been made and their flammabilities determined.