Phosphazene cyclomatrix network polymers: Some aspects of the synthesis, characterization, and flame-retardant mechanisms of polymer

• Published in: Journal of applied polymer science 2005-02, Vol.95 (4), p.880-889
• Main Authors: Zhang, Teng, Cai, Qing, Wu, De-Zhen, Jin, Ri-Guang
• Format: Article
• Language: English
• Subjects: Applied sciences; cyclomatrix; Exact sciences and technology; flame retardance; Inorganic and organomineral polymers; Physicochemistry of polymers; polyphosphazenes; Preparation; thermal properties
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.21295

Novel phosphazene cyclomatrix network polymers were synthesized via nucleophilic displacement of activated nitro groups of tri(4‐nitrophenoxy)tri(phenoxy)cyclotriphosphazene and hexa(p‐nitrophenoxy)cyclotriphosphazene with the hydroxyls of bisphenol A. Both the monomers and polymers were characterized by Fourier transform infrared (FTIR) and 1H‐NMR spectroscopy, and their structures were identified. The thermal and flame‐retardant properties of the polymers were investigated with thermogravimetric analysis in air, pyrolysis, and combustion experiments. Both solid and gaseous degradation products were collected in a pyrolysis process and analyzed with FTIR spectroscopy, gas chromatography/mass spectrometry, and scanning electron microscopy. The results demonstrated that the cyclomatrix phosphazene polymer would have excellent thermal stability and flame‐retardant properties if it could form a crosslinked phosphorous oxynitride structure during pyrolysis or combustion. A flame‐retardant mechanism of “intumescent” was proposed to elucidate the pyrolysis and combustion process. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 880–889, 2005