Zhang Haoyang, He Jiyu, Li Xiangmei
School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China.
National Engineering Research Center of Flame Retardant Materials, Beijing 100081, China.
Polymers (Basel). 2025 May 31;17(11):1537. doi: 10.3390/polym17111537.
PA66 is a widely used engineering plastic, but its flammability reduces safety during application. The 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO) and its derivatives are a class of flame retardants with excellent flame-retardant efficiency, which can significantly improve the flame retardancy of PA66. This work synthesized a DOPO derivative flame retardant, DT, containing multiple P/N elements and comprehensively characterized its structure using FTIR and NMR. Flame-retardant PA66 materials were prepared by twin-screw extrusion blending with PA66, and their thermal stability, crystallization properties, flame retardancy, and mechanical properties were investigated. When the DT content reached 15%, the vertical burning classification test achieved the UL-94 V-0, and the limiting oxygen index (LOI) rose up 27.2%. In the cone calorimeter test, the peak of heat release rate (PHRR) and total heat release (THR) of the material decreased significantly, and a distinct char layer formed, increasing NH release and decreasing the C-H structure after combustion, improving PA66 flame-retardant properties.
聚酰胺66（PA66）是一种广泛使用的工程塑料，但其可燃性会降低应用过程中的安全性。9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物（DOPO）及其衍生物是一类具有优异阻燃效率的阻燃剂，能够显著提高PA66的阻燃性。本工作合成了一种含多个P/N元素的DOPO衍生物阻燃剂DT，并通过傅里叶变换红外光谱（FTIR）和核磁共振（NMR）对其结构进行了全面表征。采用双螺杆挤出共混法将其与PA66制备成阻燃PA66材料，并对其热稳定性、结晶性能、阻燃性和力学性能进行了研究。当DT含量达到15%时，垂直燃烧分级试验达到UL-94 V-0级，极限氧指数（LOI）提高了27.2%。在锥形量热仪试验中，材料的热释放速率峰值（PHRR）和总热释放量（THR）显著降低，并形成了明显的炭层，燃烧后NH释放增加，C-H结构减少，提高了PA66的阻燃性能。
