用热重分析法和热解色谱质谱联用技术(Py-GC-MS)对工业碱木素热解行为进行了初步研究,分析了工业碱木素在不同升温速率下的热分解特性。结果表明,工业碱木素的热解过程主要分为4个阶段,在200℃以下的低温区和300-500℃的中温区各有1个强烈失重峰。工业碱木素热裂解产物非常复杂,Py-GC-MS分析表明,在300℃下的热解产物中,以源于工业碱木素的聚糖热解产物为主,含有一定量的低分子木素热解构产物;在450℃下的热解产物中,以木素大分子的热解构产物为主,例如各种酚类化合物、愈创木基丙酮等酮类化合物及源于木素-碳水化合物复合体的阿魏酸等化合物。
Pyrolysis characteristics of technical alkali lignin were studied using thermogravimetric analysis and pyrolysis coupled with gas chromatography and mass spectrometry(Py-GC-MS). The effects of heating rate on the pyrolysis characteristics of technical alkali lignin were investigated. The results show that the nonisothermal weight-loss process of technical alkali lignin was composed of four areas, including two peaks of rapid weight- loss below the pyrolysis temperature of 200℃ and between the pyrolysis temperature of 300 - 500℃. By the analysis of Py-GC-MS, the component of pyrolysis products from technical alkali lignin was very complex, the chief products at 300℃mainly were derived from the decomposition of carbohydrates in technical alkali lignin and other pyrolysis products were from the cleavage of low molecule lignin. The chief pyrolysis products at 450℃ were mainly derived from the cleavage of lignin, such as phenolic compounds, guaiacyl acetone and ferulic acids from lignin-carbohydrates complex.