Abstract: The synergism flame retardant effect of expandable graphite(EG) and intumescent flame retardant(IFR) on road asphalt was investigated by limiting oxygen index(LOI) and the flame retardant mechanism was analyzed by scanning electron microscopy(SEM).The results revealed synergism of EG and IFR has a good flame retardant effect which greatly improved LOIs and enhanced thermal stability by forming inflation homogenous porous carbon layer after combustion. It was confirmed by SEM that flame retardant synergism mechanism of EG and IFR on road asphalt lied in the carbon condensed phase which promoted formation of carbon layer and increased surface expansion rate of asphalt. 

Key words: Expandable graphite,    ,  Intumescent flame retardant,    ,  Limiting oxygen index,    ,  Scanning electron microscopy

摘要： 采用氧指数测定( LO I ) 对道路阻燃沥青中膨胀型阻燃剂( I F R) 、 可膨胀石墨( E G) 以及两者协同体系 ( I F R - E G) 的阻燃效果进行了考察, 同时采用扫描电镜( S EM) 技术手段对阻燃机理进行了分析。结果表明, E G与 I F R体系复配后有很好的协同阻燃效果, 制得的阻燃沥青氧指数明显升高, 热稳定性能增强, 燃烧后形成膨胀多孔均 质碳层。扫描电镜( S EM) 结果表明, 膨胀型阻燃体系在道路沥青中的协同阻燃机理在于凝聚相成炭, 即能促进聚合 物成碳, 沥青表面膨胀率明显提高。

关键词: 阻燃沥青, 可膨胀石墨, 膨胀型阻燃体系, 氧指数测定, 扫描电镜