氧气对阻燃复合材料火灾危险性及痕迹特征的影响

Influence of oxygen on the fire hazard and trace characteristics of flame retardant composites

氧气是影响可燃物火灾危险性和残留物痕迹特征的一个重要因素。运用火焰传播量热仪、相机、扫描电镜等研究不同氧气体积分数下阻燃聚氨酯泡沫(FPUF)、阻燃中密度板(MDF)的燃烧性能和残留物痕迹特征等,分析总结了氧气体积分数对其相关性能的影响。研究表明:FPUF和MDF同为阻燃复合材料,但由于材质、阻燃机理等不同,氧气体积分数对二者的火灾危险性影响有较大差异。随着氧气体积分数降低,FPUF的火灾蔓延指数(FGI)显著减小,而MDF的FGI虽然也受氧气体积分数的影响,但与FPUF相比,受影响程度要弱得多。另外,随着氧气体积分数降低,FPUF的燃烧残留量增加,炭层架构完整性提高,黑褐色加深。MDF的残留物颜色整体呈土黄色,宏观上均呈龟裂状,随着氧气体积分数降低,龟裂裂缝增大,黑色炭化物增多,微观纤维化增强。

Oxygen is an important factor affecting the fire hazard and residues trace of combustible materials.In this paper,flame propagation calorimeter,camara,scanning electron microscope and other methods were used to study the combustion performance,residues trace of the flame retardant flexible polyurethane foam(FUPF)and flame retardant medium-density fiberboard(MDF)at different oxygen volume fraction.And the effects of oxygen volume fraction on the related properties of them were analyzed and summarized.The results show that FPUF and MDF were both flame retardant composites,but due to the different materials and flame retardant mechanism,the influence of oxygen volume fraction on the fire risk of them was very different.With the decrease of oxygen concentration,the fire growth index(FGI)of FPUF decreased significantly,while the FGI of MDF also decreased,but the degree of influence was much weaker than that of FPUF.In addition,with the decrease of oxygen volume fraction,the residues amount of FPUF increased,the integrity of the structure was significantly improved and the residues gradually turned black brown.The macroscopic state of MDF earthy-yellow residues was cracked on the macro level.With the decrease of oxygen volume fraction,the cracking crack got wider,with increased black carbonization and enhanced microscopic fibrosis.