可膨胀石墨和碳纳米管对PMMA火蔓延特性的影响  

Effects of expanded graphite and carbon nanotubes on fire spread characteristics of PMMA

作　　者：刘珂[1] 张英[1] 张威[1] 吴淑娴[1] 潘文砚 Ke LIU;Ying ZHANG;Wei ZHANG;Shuxian WU;Wenyan PAN(Department of Safety Science and Engineering,Wuhan University of Technology,Wuhan,Hubei 430070,China)

机构地区：[1]武汉理工大学安全科学与应急管理学院,湖北武汉430070

出　　处：《过程工程学报》2021年第9期1054-1063,共10页The Chinese Journal of Process Engineering

基　　金：国家自然科学基金资助项目(编号:51706164)。

摘　　要：通过熔融共混法制备了9种PMMA复合阻燃材料,对其进行小尺寸的水平火蔓延实验研究,对比分析了可膨胀石墨(EG)和碳纳米管(Carbon Nanotube,CNTs)阻燃剂的加入对材料燃烧特性的影响,主要研究了火蔓延速度、火焰形态、固相温度、质量损失速率等火蔓延特性参数变化规律。结果表明,EG能产生阻燃效应,随EG含量增加,复合材料的火蔓延速度、质量损失速率、表面热流密度均有所减小;CNTs表现出拮抗和协同阻燃的复合效应。EG含量较低时,添加1%CNTs反而会使火蔓延速率加快;随着EG含量增加,拮抗作用逐渐消失,最后表现为协同阻燃,原因是CNTs的高热导率、"灯芯效应"促进表面燃烧作用和EG/CNTs体系阻燃性之间存在竞争关系;添加EG和CNTs前后,火蔓延过程中表现出明显不同的燃烧行为,未添加阻燃剂前PMMA会产生熔融滴落物积聚成池火,表现为明显的热塑性材料燃烧特征;加入EG和CNTs后则会形成碳层,表现为明显的可碳化材料燃烧特征。Nine types of PMMA composite flame retardant materials were prepared by the melt blending method,and small-scale horizontal fire spread experiments were conducted on them.The effects of flame retardants of expandable graphite(EG)and carbon nanotube(CNTs)on the combustion characteristics of materials were compared and analyzed.The change rules of fire propagation characteristics parameters,such as fire propagation velocity,flame morphology,solid phase temperature and mass loss rate,were mainly studied.The results showed that EG mainly exhibited flame-retardant effect.With the increase of EG content,the fire propagation velocity,mass loss rate and surface heat flux of the composite material all decreased.CNTs exhibited a compound effect of antagonistic and synergistic flame retardancy.When the content of EG was low,the addition of 1%CNTs accelerated the fire spreading rate.Subsequently,with the increase of EG content,its antagonistic effect gradually disappeared,and finally showed the synergistic flame-retardant effect.The high thermal conductivity of CNTs and the"wick effect"promote combustion,and EG/CNTs system prevented combustion.There was a competitive relationship between them.After adding EG and CNTs,the fire spreading process showed obviously different combustion behavior.Before adding flame retardant,PMMA produced molten drips and accumulate into a pool fire,showing obvious burning characteristics of thermoplastic materials;adding EG and CNTs,a carbon layer formed,showing obvious burning characteristics of carbonizable materials.

关 键 词：聚甲基丙烯酸甲酯 可膨胀石墨 碳纳米管 阻燃材料 水平火蔓延 

分 类 号：TQ325.7[化学工程—合成树脂塑料工业]