A novel bridged 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) derivative (PN-DOPO) was used to fabricate a flame-retardant glass fiber-reinforced polyamide 6T (GFPA6T). The effects of PN-DOPO on the flame retardancy, thermal decomposition, and pyrolysis behavior of GFPA6T was systematically investigated, compared to neat GFPA6T and its composite flames retarded by aluminium diethylphosphinate (OP1230). The flame retardancy, thermal stabilities, and burning behaviors of the composites were evaluated by vertical burning test (UL-94), limiting oxygen index (LOI), thermogravimetric analysis (TGA), and cone calorimeter test. Moreover, the flame-retardant mechanism was analyzed by pyrolysis-gas chromatograph/mass spectrometer (Py-GC/MS), Fourier transform infrared coupled with the thermogravimetric analyzer (TG-FTIR), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. Results reveal that the modified GFPA6T, with the addition of 15 wt% PN-DOPO, achieves a V-0 rating and LOI value of 28.9%, whereas introducing OP1230 at levels up to 17.5 wt% can achieve a V-0 rating and LOI value of 40.1%. The superior flame retardancy for GFPA6T/PN-DOPO system can be attributed to two factors as follows: the release of pyrolytic gases containing phosphorus-based aromatic structures and nonflammable gases at the early stage, thereby playing an important role in the gas phase, and the formation of char layer consisting of phosphorus-containing char layer and polyaromatic structures in the condensed phase. In comparison, diethyl-phosphorus oxides and their derivatives are detected in the gas phase for GFPA6T/OP1230 samples, and the residues consist of aluminum phosphorus oxides, polyphosphates, and a slight amount of charred polymer.

一种新型的9,10-二氢-9-氧杂-10-菲菲-10桥接（DOPO）衍生物（PN-DOPO）被用于制造阻燃玻璃纤维增​​强聚酰胺6T（GFPA6T）。与纯净的GFPA6T及其复合火焰被二乙基次膦酸铝（OP1230）阻滞相比，系统地研究了PN-DOPO对GFPA6T的阻燃性，热分解和热解行为的影响。通过垂直燃烧测试（UL-94），极限氧指数（LOI），热重分析（TGA）和锥形量热仪测试来评估复合材料的阻燃性，热稳定性和燃烧行为。此外，通过热解气相色谱/质谱仪（Py-GC / MS），傅立叶变换红外光谱仪和热重分析仪（TG-FTIR）来分析阻燃机理。扫描电子显微镜（SEM），X射线光电子能谱（XPS）和拉曼光谱。结果显示，添加15 wt％PN-DOPO的修饰的GFPA6T达到了V-0等级和28.9％的LOI值，而以最高17.5 wt％的水平引入OP1230可以达到V-0等级和LOI价值的40.1％。GFPA6T / PN-DOPO系统优异的阻燃性可归因于以下两个因素：早期释放出含磷基芳香结构的热解气体和不易燃气体，从而在气相中起重要作用；以及在冷凝相中形成由含磷炭层和多芳族结构组成的炭层。相比之下，GFPA6T / OP1230样品在气相中检测到二乙基磷氧化物及其衍生物，