聚苯乙烯/纳米氢氧化镁复合材料的结构和燃烧行为研究

Study on Structure and Combustion Behavior of PS/Nano-MH Composite

将聚苯乙烯(PS)与表面经过改性的纳米氢氧化镁(nano-MH)进行熔融复合,制备了PS/nano-MH复合材料,采用扫描电镜对复合材料的微观结构进行了分析,用水平燃烧实验、氧指数实验、高温处理实验和锥形量热实验研究了复合材料的燃烧行为。结果表明:nano-MH颗粒表面经过硅烷偶联剂改性后,在PS基体中的团聚减少,分散更加均匀;nano-MH的加入使PS的阻燃性能得到明显改善,随着nano-MH用量的增加,复合材料的发烟和滴落减少,氧指数增大,水平燃烧级别提高,材料燃烧时的热释放速率和质量损失速率显著下降,在高温下更加稳定;nano-MH用量为60phr时复合材料燃烧时不再滴落,100phr时能够自熄,氧指数达到24.1%,水平燃烧级别可达到FH-1级;nano-MH分解产生的氧化镁增强了材料在高温下的热稳定性。

The polystyrene （PS）/nano-magnesium hydroxide （nano-MH） composites were prepared by direct melt compounding PS and surface-modified nano-MH. The microstructure of the composites was studied with SEM. The combustion behavior of the composites was investigated by means of horizontal burning, oxygen index, high temperature treatment and cone calorimetry. The results show that the agglomeration of the nano-MH particles is reduced and their dispersion in the PS matrix becomes more even after surface treatment with silane coupling agent. The addition of nano-MH greatly improves the flame retardancy of PS. With the increase of nano-MH content, both the released smoke and melt dripping of the composites gradually diminish, accompanied with increase of oxygen index and horizontal burning rating, meanwhile, the heat release rate and mass loss rate of the composites decrease, and the thermal endurance of the composites is enhanced remarkably. The melt dripping ceases when the content of nano-MH reaches 60 phr. With the addition of 100 phr nano-MH, self-extinguishing occurs, the oxygen index of the composite reaches 24.1%, and the composite meets FH-1 rating in the horizontal burning test. It is found that MgO produced by degradation of nano-MH enhances the thermal stability of the composites under high temperatures.