改性纳米二氧化硅协效二乙基次磷酸铝阻燃尼龙6

Modified Nano-Silica Synergistic Aluminum Diethylphosphinate Flame Retardant Nylon 6

使用有机无机杂化纳米二氧化硅(DNS-M)和可反应性纳米二氧化硅(RNS-A)分别协效二乙基次磷酸铝(ADP)用于阻燃尼龙6(PA6)。研究发现,DNS-M和RNS-A都是以促进气相阻燃为主、凝聚相阻燃为辅的作用机制。当ADP添加量为9%(质量分数,下同),DNS-M和RNS-A的添加量均为1%时,复合材料的垂直燃烧等级均可达到V-0级,热释放速率峰值分别下降到309.5 kW/m^(2)和239.1 kW/m^(2)。对比总热释放量(THR)和热释放速率峰值(PkHRR)可以发现,RNS-A体系的阻燃效果优于DNS-M体系。RNS-A体系的THR和PkHRR相比DNS-M体系分别降低了11.1%和22.7%,并且由于RNS-A表面具有可反应的氨基,可提高阻燃填料与基体之间的相互作用,改善其在基体中的分散性和相容性,因而相比DNS-M体系,RNS-A体系的拉伸强度和冲击强度分别提高了2.3%和39.4%。

Flame retardant PA6 composites were prepared using organic-inorganic hybrid nano-silica(DNS-M)and reactive nano-silica(RNS-A)as synergist respectively compounded with aluminum diethylphosphinate(ADP).The study found that the mechanism of DNS-M and RNS-A are both mainly to promote gas phase flame retardancy,supplemented by condensed phase.When the addition of DNS-M and RNS-A are both 1%combined with 9%ADP(mass fraction,the same below),the vertical burning test of the composites can reach the V-0 level,their peak heat release rate dropped to 309.5 kW/m^(2)and 239.1 kW/m^(2).Comparing the total heat release(THR)and the peak heat release rate(PkHRR),it can be found that the flame retardant effect of RNS-A system is better than that of DNS-M system and the THR and PkHRR of the RNS-A system are reduced by 11.1%and 22.7%respectively.Moreover,the reactive amino groups on the surface of RNS-A can enhance the interaction between the flame retardant filler and the matrix,improving the dispersibility and compatibility.Therefore,the bending strength and impact strength of the RNS-A system are increased by 2.3%and 39.4%,respectively.