典型纺织品热稳定性及热解动力学研究

Study of thermal stability and thermodynamics of typical textiles

采用同步热分析仪(simultaneous thermal analyzer,STA)对棉、麻、真丝、涤纶4种典型可燃物纺织品进行热解反应失重动力学研究,分析了4种不同升温速率5、10、15、20℃/min条件下热解温度对样品热解过程的影响,通过对热重(thermogravimetric,TG)曲线、差分热重(differential thermogravimetric,DTG)曲线、差示扫描量热(differential scanning calorimetry,DSC)曲线的分析,使用Caots-Redfern法获得4种纺织品的热解动力学参数。研究表明,纺织品热解失重过程与样品种类及其组成成分有关,天然纤维中棉的阻燃性能最弱,主要成分为化学合成纤维的涤纶DSC曲线最大放热峰峰值温度最高;升温速率的增加促进热解反应的进行,高升温速率条件下纤维素更有利于分解生成多种挥发性物质;将热解过程分为多个阶段,使用Caots-Redfern法建立一级动力学模型并获得了主要热解阶段相应的热解动力学参数。

The thermogravimetric analysis of the weight loss kinetics of four typical combustible fabrics,cotton,hemp,silk,and polyester,was conducted by using a simultaneous thermal analyzer(STA).The pyrolysis process of different samples at 5,10,15 and 20℃/min heating rates was analyzed by thermogravimetry(TG),differential thermogravimetry(DTG)and differential scanning calorimetry(DSC)curves.The Caots-Redfern method was used to obtain the pyrolysis kinetic parameters of four kinds of textiles.The research shows that the weight loss process of textile pyrolysis is related to the types of samples and their components.The flame retardancy of cotton in natural fiber is the weakest.The maximum exothermic peak-peak temperature of DSC curve of polyester,whose main component is chemical fiber,is the highest.The increase of heating rate promotes the pyrolysis reaction.The cellulose is more dehydrated under the condition of low heating rate,and more conducive to the decomposition and formation of multiple volatile substances under the condition of high heating rate.The pyrolysis process is divided into phases,and a first-order kinetic model was established by using the Caots-Redfern method.The corresponding pyrolysis kinetic parameters of the main pyrolysis stage are obtained.