可膨胀石墨在膨胀阻燃体系中协同阻燃作用的研究

Study on Synergistic Effect of Expandable Graphite in Intumescent Flame Retardant Polyethylene

采用氧指数(LOI)、扫描电镜(SEM)、热重分析(TG)等技术手段对可膨胀石墨(EG)与膨胀型阻燃剂(IFR)协同阻燃线性低密度聚乙烯(LLDPE)体系进行了研究.结果表明,EG与IFR复配,体系氧指数明显提高,其热稳定性增强,热降解速率降低,残炭率提高,燃烧炭层连续致密,EG与IFR具有很好的协同阻燃作用.热分析及扫描电镜结果证明,EG与IFR的协同阻燃作用机理的关键在于凝聚相成炭.

The flame retardant synergism of expandable graphite （EG） and intumescent flame retardant （IFR） in linear low density polyethylene （LLDPE） was investigated by means of limiting oxygen index （ LOI）, scanning electron microscopy （SEM） and thermogravimetric analysis （TG）. The results revealed good synergism between EG and IFR which greatly improved LOIs and thermal stability of the system and enhanced the formation of compact char layer, leading to lower thermal degradation rate and more residue left. It was confirmed by TG and SEM that the flame retardant synergistic mechanism of EG and IFR mainlv lies in the condensed phase.