聚磷酸三聚氰胺阻燃玻纤增强PA66和PA6的区别

Differences in Flame Retardancy of Melamine Polyphosphate Between Fiberglass Reinforced PA66 and PA6

采用聚磷酸三聚氰胺(MPP)分别对玻纤增强的PA66和PA6进行了阻燃.发现MPP在PA66中的阻燃效果明显优于PA6.添加质量分数为25%的MPP,能使玻纤增强PA66的氧指数由20.4%提高到38.0%,且能通过UL94V-0阻燃级;但对玻纤增强的PA6阻燃效果则不显著,氧指数只提高了5.5%,垂直燃烧性能没有改善.对两组样品分别进行了热失重分析,发现MPP对PA6和PA66的热降解过程的影响是不同的.对600℃处理后所得的残炭进行了扫描电镜分析,发现所形成的炭层结构的不同导致了阻燃效果的差别.

Flame retarded fiberglass reinforced PA66 and PA6 were prepared by adding melamine polyphosphate (MPP). The experimental results show that the effectiveness of melamine polyphosphate is distinctly higher in the fiberglass reinforced PA66 than PA6 in spite of the fact that the elemental composition of PA66 and PA6 remains all the same. By adding 25% MPP to fiberglass reinforced PA66, the LOI was improved from 20.4% to 38.0% and the vertical flammability test of UL94 could reach V-0 class; but the flame retardancy of fiber reinforced PA6 was not distinctive. The increase of LOI was only 5.5% and the vertical flammability performance was not improved. Thermal degradation behavior of the specimen was studied by thermal gravimetric analysis (TGA). It was discovered that the thermal degradation behaviors were different between PA6 and PA66 by adding MPP. The residual char was formed by heating the materials to 600℃ and its structure was observed by scanning electron microscopy (SEM).The test resuls show that it is the difference in the char structure that leads to the difference in flame retardancy.