Condensation reactions of some lignin related compounds at relatively low pyrolysis temperature
Condensation reactions of some lignin related compounds at relatively low pyrolysis temperature
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DOI：
10.1080/02773810701515143
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发表时间：
2007-01-01
影响因子：
2
通讯作者：
Saka, Shiro
中科院分区：
文献类型：
--
作者：
Nakamura, Takeshi;Kawamoto, Haruo;Saka, Shiro
研究了几种木质素相关化合物在空气/250℃/2 h热解条件下的缩合反应。愈创木酚、甲基愈创木酚和甲基藜芦醇的回收几乎是定量的，少量的自由基偶联产物来源于苯氧基和苄基自由基。侧链(C-α=C-β，C-α-OH)显著提高了缩合反应活性。从二聚体结构来看，乙烯基缩合和苯二酚甲醚机理是这些化合物的重要缩合途径。对于木质素初级裂解生成的结构的模型化合物，针叶醇(来自β-乙醚结构)活性很高，而4，4‘-二羟基-3，3’-二甲氧基二苯乙烯(来自β-芳基结构)很稳定。
Condensation reactions of some lignin related compounds were studied under the pyrolysis conditions (air/250 degrees C/2 h). Guaiacol, methylguaiacol and methylveratrole were recovered almost quantitatively with small amount of radical coupling products derived from phenoxy and benzyl radicals. Side-chains (C-alpha=C-beta, C-alpha-OH) increased the condensation reactivity substantially. From the dimer structures, vinyl condensation and quinone methide mechanisms were indicated as important condensation pathways for these compounds. As for model compounds for the structures formed in lignin primary pyrolysis, coniferyl alcohol (from beta-ether structure) was very reactive, while 4,4 '-dihydroxy-3,3 '-dimethoxystilbene (from beta-aryl structure) was stable.