New Diamine Phosphonate Monomers as Flame-Retardant Additives for Polymers

Abstract

Three new phosphonate-amine monomers were synthesized in high yields starting from commercially available aldehydes. Complete NMR and FAB-MS mass spectrometry characterization is reported for all compounds, which are useful monomers for the synthesis of phosphorus-containing flame-retardant polymers.

Keywords:

• bis-α-Amino-phoshonate
• characterization
• FAB
• monomers phosphonated
• NMR

Acknowledgments

We thank the Italian Ministry for University and Research (MIUR) for financial support.

Notes

We can exclude, in the room temperature spectra of our samples, the presence of conformers arising from the restricted rotation of the Cbz (carbamate) group because in previous work ¹⁴ dealing with mono benzyl (diphenoxyphosphoryl)(phenyl)methylcarbamate derivative we did not detect any additional complexity signals arising from the presence of this group. Moreover, in the case of bis-Cbz derivatives (3a–c), if restricted rotation is present, more complex NMR spectra should be noticed, due to the presence of (Z,Z), (Z,E), and (E,E) rotamers, and this is not the case for our compounds. Furthermore, the hydrolysis of 3c yields the two expected diasteremers (racemo and meso, Table 2). Thus, all data clearly indicate that the NMR spectra are well explained by the formation of the two possible diastereomers.