废弃碳纤维/环氧树脂复合材料的热解特性及动力学研究

PYROLYSIS CHARACTERISTICS AND KINETICS OF SCRAP CARBON FIBER REINFORCED EPOXY RESIN MATRIX COMPOSITES

采用热重分析仪对废弃碳纤维/环氧树脂复合材料(CF/EP复合材料),分别在升温速率为6. 67℃·min^(-1)、10℃·min^(-1)和13. 33℃·min^(-1)下进行热解,考察了不同气氛及不同升温速率对CF/EP复合材料热解的影响。结果表明:升温速率和反应气氛对废弃CF/EP复合材料热解过程及特性有重要影响;废弃CF/EP复合材料在氮气氛下热解反应速率较快阶段只有一个阶段,为第一失重阶段,且为一级反应模式。废弃CF/EP复合材料在空气氛下的热解反应速率较快阶段有两个阶段,第一失重阶段为二级反应模式,第二失重阶段为0. 5级反应模式;空气氛下热解第一失重阶段在相同分解温度下与氮气氛下热解反应机理不同;提高升温速率可显著增加废弃CF/EP复合材料热解的表观活化能和指前因子;经外推法可知,氮气氛表观活化能为55. 84 kJ·mol^(-1),空气氛第一失重阶段表观活化能为39. 24 kJ·mol^(-1),第二失重阶段表观活化能为-8. 62 kJ·mol^(-1)。

The pyrolysis process of a scrap carbon fiber reinforced epoxy resin matrix composite has been studied under different heating rates of 6.67℃·min^-1,10℃·min-1 and 13.33℃·min-1 using thermogravimetric methods.The effects on pyrolysis of the composite of varying atmosphere and heating rate were studied.The results show that the pyrolysis heating rate and atmosphere both have a significant effect.In a nitrogen atmosphere the scrap carbon fiber reinforced epoxy resin matrix composite has only one thermal decomposition stage and follows a first-order reaction model.In air there are two decomposition stages following a second-order reaction model and a 0.5-order reaction model.The apparent activation energy and frequency factor of the thermal decomposition of the scrap carbon fiber reinforced epoxy resin matrix composite are both increased significantly when the heating rate is increased.In the nitrogen atmosphere the apparent activation energy is 55.84 kJ·mol^-1.In air the apparent activation energy of the first weightlessness phase is 39.24 kJ·mol^-1,and the apparent activation energy of the second weightlessness stage is-8.62 kJ·mol^-1.