Synthesis of novel nitrogen-phosphorus flame retardants and their flameproof to flammable polymers

To prepare the efficiently flame retardants (FR) for the highly flammable polymers, the novel nitrogen-phosphorus based FRs (P-N FR) (PN-3, PN-4, PN-5, and PN-6) were prepared via phosphorus halides and amine derivatives with 40- 90 % in yields. The appearance of P-N FRs are lightly white solid. All P-N FRs are water-insoluble and show a melting point above 40oC. The success of the synthesis was confirmed by NMR analysis.