碳纤维、玻璃纤维/环氧树脂热解及燃烧特性对比

Comparison of pyrolysis and combustion characteristics of carbon fiber,glass fiber/epoxy resin

民用飞机内饰壁板材料主要是纤维/树脂复合材料,该类复合材料具有一定的火灾危险性,因此研究其热稳定性和燃烧特性对于飞机防火具有重要意义。采用热重分析仪研究了不同升温速率对碳纤维/环氧树脂和玻璃纤维/环氧树脂两种典型飞机壁板材料热解的影响,并使用Kissinger法得到了分解阶段的表观活化能和指前因子;采用锥形量热仪研究了两种预浸料在不同火灾环境下的燃烧特性,并选取火势蔓延指数(δFGI)、火险潜在指数(δFPI)、放热指数(δTHRI)、发烟指数(δTSPI)4种评价指标评估其火灾危险性;进而分析两种纤维在树脂复合材料热解、燃烧过程中的影响。结果表明:在空气气氛下,升温速率对两种预浸料的热解影响都较大,碳纤维在556℃以上发生分解,玻璃纤维未发生分解。在热解时玻璃纤维预浸料前两阶段的活化能明显高于碳纤维预浸料,表明玻璃纤维预浸料具有更高的热稳定性。碳纤维预浸料的热释放速率、产烟速率、总产热量、总产烟量均大于玻璃纤维预浸料,随着热辐射强度的增加,两种预浸料这些参数之间的差值都不断变大,碳纤维预浸料的δFGI、δTHRI、δTSPI均大于玻璃纤维预浸料,δFPI值则相反。分析发现,两种纤维都对复合材料的热解有一定的抑制作用,但玻璃纤维抑制作用更明显,碳纤维/环氧复合材料火灾危险性更大。

Civilian aircraft interior wall panel materials are mainly fibre/resin composites,which have a certain fire hazard,so the study of their thermal stability and combustion characteristics is of great significance for aircraft fire protection.A thermogravimetric analyzer was used to study the influence of different heating rates on the pyrolysis of two typical aircraft siding materials:Carbon fiber/epoxy resin and glass fiber/epoxy resin,and the apparent activation energy and pre-digital factor of the decomposition stage were obtained using the Kissinger method.The cone calorimeter was used to study the combustion characteristics of two prepregs in different fire environments,and four evaluation indicators of fire growth index(δFGI),fire potential index(δFPI),thermal heat release index(δTHRI)and thermal smoke produce index(δTSPI)were selected to evaluate the fire hazard;and then the two types of fibers were analyzed.Furthermore,the influence of the two kinds of fibers in the pyrolysis and combustion process of the resin composite was analyzed.The results show that in air atmosphere,the heating rate has a greater influence on the pyrolysis of the two prepregs.The carbon fiber decomposes above 556℃,and the glass fiber does not decompose.During pyrolysis,the activation energy of the first two stages of the glass fiber prepreg is significantly higher than that of the carbon fiber prepreg,indicating that the glass fibre prepreg has a higher thermal stability.The heat release rate,smoke production rate,total heat production,and total smoke production of carbon fiber prepregs are greater than those of glass fiber prepregs.As the heat radiation intensity increases,the differences between these parameters of the two prepregs are all keep getting bigger,theδFGI,δTHRIandδTSPIof carbon fiber prepreg are larger than glass fiber prepreg,while theδFPIvalue is the opposite.The analysis finds that both fibres inhibite the pyrolysis of the composite,but the glass fibre inhibites it more significantly and the carbon fibre/epoxy composite have a greater fire hazard.