DMD处理KP浆时残余木素结构的变化

Changes of Residual Lignin in Eucalyptus Kraft Pulping Coupled with DMD Delignification

利用紫外、红外光谱以及核磁共振等对DMD(二甲基二环氧乙烷)处理前后纸浆残余木素的研究表明:DMD脱木素后纸浆木素中的游离酚羟基含量变化不大,这是因为DMD不仅能与具有游离酚羟基的木素结构单元反应,而且能与醚化了的单元起反应,增加了带有游离酚羟基的降解产物。

Dimethyldioxirane (DMD) is a selectively effective delignifying agent. Eucalyptus was kraft pulped with DMD treatment. The resulted unbleached pulp was subjected to acid hydrolysis to have its residual lignin isolated. Chemical changes of the residual lignin in the DMD treated pulp were studied through elemental and methoxyl analyses, whereas structural changes of the residual lignin were examined through 1H NMR and 13 C NMR. The results obtained suggested that DMD treatment brought about extensive oxidation in the residual lignin. And, the structural changes in the residual lignin suggested that new phenolic radicals were being formed, indicating the potentiality of DMD treatment in delignification enhancement.