Degradation of the Cellulosic Key Chromophore 5,8-Dihydroxy-[1,4]-naphthoquinone by Hydrogen Peroxide under Alkaline Conditions
作者:Nele Sophie Zwirchmayr、Takashi Hosoya、Ute Henniges、Lars Gille、Markus Bacher、Paul Furtmüller、Thomas Rosenau
DOI:10.1021/acs.joc.7b01827
日期:2017.11.3
presented study, DHNQ was treated with hydrogen peroxide under alkaline conditions at pH 10, resembling the conditions of industrial hydrogen peroxide bleaching (P stage). The reaction mechanism, reaction intermediates, and final degradation products were analyzed by UV/vis, NMR, GC–MS, and EPR. The degradation reaction yielded C1–C4 carboxylic acids as the final products. Highly relevant for pulp bleaching
5,8-二羟基-[1,4]-萘醌(DHNQ)是纤维素材料中的关键发色团之一。它在纤维素材料中几乎无处不在,使其成为制浆造纸业漂白工作的目标分子。在本研究中,DHNQ在pH 10的碱性条件下用过氧化氢处理,类似于工业过氧化氢漂白的条件(P阶段)。通过UV / vis,NMR,GC-MS和EPR分析了反应机理,反应中间体和最终降解产物。降解反应产生C 1 –C 4羧酸作为最终产物。与纸浆漂白高度相关的是反应中间体的发现,因为其中的两个是2,5-二羟基-[1,4]-苯醌(DHBQ)和1,4,5,8-萘乙酮,它们本身都是有效的生色团。 。虽然DHBQ是三个主要的纤维素发色团之一,并且已经很好地确定了其被H 2 O 2降解的能力,但第二个中间体1,4,5,8-萘乙酮是在纤维素变色的背景下首次报道的。