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在针叶木浆和阔叶木浆的H2O2漂白中,分别从卡伯值的降低、己烯糖醛酸(HexA)和木素的脱除等方面研究了过氧化钼酸盐即[MoO(O2)2(OH)(H2O)]–的催化作用。在阔叶木浆的过氧化钼酸盐漂白段,HexA下降的同时卡伯值也下降60%以上。对松木浆而言,在H2O2漂白过程中添加钼酸盐可使卡伯值降低4.1。在相同条件下的H2O2漂白中,若不添加钼酸盐,木素和HexA就不会发生如此显著的反应。为了研究其反应机理,用具有不同侧链结构的木素模型化合物与过氧化钼酸盐反应。通过核磁共振氢谱图(1H-NMR)可发现具有芳香环与双键结构的木素模型化合物与过氧化钼酸盐催化系统能十分迅速地发生羟基化反应。这一机理可通过对浆料样品的X射线电子能谱图(XPS)的分析得以证明,并可发现活性H2O2以相同的方式与表面的木素反应。
In the H2O2 bleaching of softwood and hardwood pulps, the effects of molybdate peroxides, such as [MoO (O2) 2 (OH) (H2O)] -. In the bleaching stage of the pullulan molybdate of hardwood pulp, the Kappa number also dropped by more than 60% while the HexA decreased. For pine pulp, the addition of molybdate during H2O2 bleaching reduces the kappa number by 4.1. In the same conditions of H2O2 bleaching, without the addition of molybdate, lignin and HexA would not have such a significant reaction. In order to study the reaction mechanism, lignin model compounds with different side chain structures were reacted with peroxodimethoxide. The 1H-NMR results showed that the lignin model compound and the molybdate molybdate catalytic system with aromatic ring and double bond structure can react very quickly. This mechanism can be demonstrated by X-ray photoelectron spectroscopy (XPS) analysis of slurry samples and it was found that reactive H2O2 reacted with surface lignin in the same manner.