Abstract: The residual lignins extracted from both the original and oxygen-delignified softwood kraft pulp and those isolated from the effluent of oxygen delignification were subjected to pyrolysis in the presence of tetramethylammonium hydroxide(TMAH).The methylated products were analyzed with gas chromatography-mass spectrometry(GC-MS) to investigate the molecular characterization and changes of the residual lignins in softwood kraft pulp during oxygen delignification.The results indicated that pyrolysis of the lignins yielded primarily methylated guaiacyl derivatives.Oxidation under alkali oxygen conditions could induce fragmentation in lignin and produce more acid groups, and the lignin molecules with short side chains(C₁ and C₂) could be preferentially removed from pulps during oxygen delignification.

Key words: 四甲基氢氧化铵, 裂解, 氧漂, 针叶木硫酸盐浆

摘要： 从针叶木硫酸盐原浆、氧漂浆以及氧漂后的废液中分离出残余木素，在四甲基氢氧化铵（TMAH）存在下，采用裂解气相色谱-质谱联用(Py-GC-MS)的方法研究了氧漂过程中木素分子结构的变化.对裂解产物的分析表明，木素裂解时产生多种甲基化的芳香化合物，以愈创木基型化合物为主;氧漂能够氧化和降解木素分子，产生更多的羧基化合物，氧化程度高的木素分子容易从纸浆中溶出，氧漂优先脱除沉积在纤维表面上的短侧链木素.

关键词: 四甲基氢氧化铵, 裂解, 氧漂, 针叶木硫酸盐浆