含氮量对硝化纤维素热解过程影响研究

Study on influence of nitrogen content on nitrocellulose pyrolysis process

为明确含氮量对硝化纤维素(NC)热解过程的影响,借助傅里叶变换红外光谱仪(FTIR)、热重分析(TG)-FTIR(TG-FTIR)和裂解(Py)-气相色谱(GC)/质谱分析仪,揭示不同含氮量NC的结构特征、热解特性和过程产物。结果表明:随着含氮量的增加,NC的取代硝基数量增多,热解反应速率和反应进行程度随之增加,轻质气体比例增大且产物种类增多,高温下出现多种化学重组形式;NC的热解过程是先发生脱硝反应,再将大分子分解为小分子,然后发生碳骨架和环内氧桥断裂,通过明确不同含氮量NC的共性产物和各阶段主要的氮氧化物,建立一种基于温度划分原则的NC热解过程机制。

In order to study the effect of nitrogen content on pyrolysis process of NC,Fourier Transform Infrared spectrometer(FTIR),thermogravimetric analysis(TG)-FTIR and pyrolysis(Py)gas chromatography(GC)/mass spectrometry(MS)are used to reveal the structural characteristics,pyrolysis characteristics and process products of NCs with different nitrogen content.The results show that with the increase of nitrogen content,the amount of substituted nitro of NC increases,the pyrolysis reaction rate and reaction degree increase,the proportion of light gas increases and the product types increase,and a variety of chemical recombination forms appear at high temperature.In the pyrolysis process of NC,de-nitration reaction takes place first,and then large molecules are decomposed into small molecules,and then carbon skeleton and ring oxygen bridge fracture occurs.By identifying the common products of NC with different nitrogen content and the main nitrogen oxides in each stage,a mechanism of NC pyrolysis process based on the principle of temperature division is established.