Py-GC-MS法研究硼及磷化合物对木质素热解产物的影响

采用裂解-气相色谱-质谱(Py-GC-MS)联机分析技术,研究了含硼及磷的化合物对紫椴(Tilia amurensis)木质素热解产物组成的影响。结果表明:木质素在裂解过程中,产生大量的CO2、CO、H2O,其主要原因是高温时羰基、羧基、羟基、甲基等脱除反应以及多环芳香族化反应的深入进行,而所选用的阻燃剂大多数都促进了CO2、CO和H2O的产生。没有经过阻燃处理的木质素热解产物中脂肪族可挥发有机化合物的比例较大,硼酸和有机磷酸盐处理过的木质素在裂解过程中这些化合物的比例明显减少。无机磷酸盐和硼砂有效降低木质素热解过程中芳香族化合物及杂环化合物的比例。FRW阻燃剂中GUP和硼酸对木质素热解过程的影响,并不是简单的加和作用,而表现出协同效应,并初步鉴定了紫椴木质素裂解产物中94种化合物的结构。

Effects of Boron Compounds and Phosphates on Pyrolysis Products of Lignin by PY-GC-MS Method

The pyrolysis products of Tilia amurensis lignin treated by boron compounds and/or phosphates were analysed by pyrolysis-gas chromatography-mass spectroscopy (Py-GC-MS). Influence of the chemicals on the composition of pyrolysis products of Tilia amurensis lignin was discussed. During the pyrolysis process, a great deal of CO2, CO and H2O was produced, which was mainly attributed to the elimination of carbonyl, carboxyl, hydroxyl, methyl and the further reaction to form polycyclic aromatic hydrocarbons. Most fire retardants used in this study promoted the release of CO2, CO and H2O. The pyrolysis of untreated lignin produced more volatile pyrolytic products than that of boric and organic phosphates treated lignin. Inorganic phosphates and sodium borate decreased aromatic and heterocyclic compounds in pyrolysis process. Guanylurea phosphate and boric acid in fire-retardant FRW were synergistic in influencing the pyrolysis process. Nine-four compounds in the pyrolysis products of Tilia amurensis lignin were identified.