摘要
木质素作为三维网状无定形高聚物,其化学结构非常复杂。为探究热解过程中产物的分布及形成路径,利用Py-GC/MS联用仪在不同的热解温度下对软木木质素中最典型的C—C键(β-5型)模型化合物的热解产物进行详细研究。结果表明:β-5型化合物在低温下主要发生C—O键的开环断裂,热解产物仍以二聚体的酚类和酮类化合物为主。随着热解温度的升高,二聚体继续发生二次裂解反应,形成大量的小分子芳香族化合物,相对含量约占15%~30%;当热解温度为900℃时,热裂解生成的化合物之间能够通过缩聚反应形成萘和茚,其相对含量约占产物含量的9%。同时,反应路径也进一步揭示了热解过程中的转化机理。
Lignin,as a three-dimensional amorphous polymer,has a complex chemical structure.In order to investigate the distribution and formation path of products in the pyrolysis process,the most typical C—C bond(β-5 linkage)model compound in softwood lignin was studied in detail by using Py-GC/MS at different pyrolysis temperatures.The results showed that C—O bond ofβ-5 linkage model compound was easily broken and the resulting products were still mainly dimers of phenols and ketones at low temperature.With increasing of pyrolysis temperature,the dimers underwent secondary cracking to form a large number of small molecular aromatic compounds,the relative content of which was about 15%to 30%.When the pyrolysis temperature was arrived at 900°C,some aromatic hydrocarbons(e.g.,naphthalene and indene)were also formed by polymerization,and for about 9%of the product content.Simultaneously,the transformation mechanism was also revealed via the reaction path during pyrolysis.
作者
黄勇
刘沙沙
顾燕倩
张书
HUANG Yong;LIU Sha-sha;GU Yan-qian;ZHANG Shu(College of Material Science and Engineering,Nanjing Forestry University,Nanjing 210037,P.R.China)
出处
《林产工业》
北大核心
2020年第9期27-31,共5页
China Forest Products Industry
基金
国家自然科学基金(51876093)
南京林业大学科研启动基金(GXL2018033)。
关键词
木质素
β-5型
模型化合物
热解机理
热解产物
Lignin
β-5 linkage
Model compounds
Pyrolysis mechanism
Pyrolysis products
