可膨胀石墨阻燃EVA燃烧性能及热失重行为的研究

用粒径为37、48及75μm的可膨胀石墨(EG)阻燃EVA,用锥形量热仪探讨了不同粒径的EG对EVA的阻燃作用,利用热失重分析仪研究了EVA/EG体系的热稳定性。结果表明:经过锥形量热仪测试表明,EVA/EG的热释放速率曲线呈现前单峰型,体现了典型的凝聚相阻燃机理;30 g EG的加入可以明显降低热释放速率,且粒径越大,阻燃效果越好;通过TG考察EG/EVA阻燃体系的热降解行为,在空气气氛下,EG膨胀炭层负载催化EVA交联成炭;相比于75μm EG,48μmEG形成炭层紧密,成炭量超过2.2%,形成的炭层稳定,在850℃也不会分解。

Study on Combustion Performance and Thermal Weight Loss Behavior of Expandable Graphite Flame Retarded EVA

Flame retardant EVA was prepared by using expandable graphite(EG) with different particle size of 37 μm,48 μm,and 75 μm as flame retardant agent respectively.The flame retarding effects of EG with different particle size on EVA were researched by CONE and the thermal stability of EVA/ EG was also studied by TG.The results show that: the shape of heat release rate(HRR) curves of flame retardant EVA by EG is front peak type,which indicates a kind of typical condensed phase flame-retardant mechanism;the HRR of EVA/EG decreases with 30 g of EG,and the flame retarding effect is better with the increase of particle size.The thermal degradation behavior of the EG/EVA was investigated by TG.The results show that: in air atmosphere,the load catalyzing effect of EG char layer accelerates char crosslinking formation of EVA;comparing to 75 μm,the carbon layer with 48 μm of EG is more tightly,the CR is more than 2.2%,the carbon layer with 48 μm of EG is more stable,and it doesn’t degrade at 850℃.