【摘要】 O3/H2O2氧化降解木素适宜的工艺条件为H2O2用量2.5%,pH值7.08,温度20℃,O3用量5%,不溶部分氧化木素的酚羟基与羧基含量明显上升,羧基含量比单独用臭氧氧化后增加了0.62mmol/g,酚羟基含量增加了0.95mmol/g;经过对不同氧化反应条件下分子质量分布的分析,与不添加H2O2的木素相比,水溶部分氧化木素有所增加,不溶部分氧化木素相对分子质量大于2000的组分的比例明显增加,氧化后木素的数均分子质量有所增加以及产生较多的醌型结构;在此条件下,磺化剂为5mmol/g时,磺化产物的水泥净浆流动度最好,达到153mm。更多还原

【Abstract】 The study indicated that alkali wheat straw lignin was degradated by O₃/H₂O₂ oxidizing, the optimum conditions of the O₃/H₂O₂ oxidizing were: H₂O₂ dosage 2.5%, ozone charge 5%, pH 7～8, temperature 20 ℃. The contents of Ph-OH and-COOH of the water insoluble lignin increased obviously after degradation by O₃/H₂O₂ oxidizing. 0.95 mmol/g and 0.62 mmol/g were increased respectively compared with the oxidation only with ozone. After the analysis of molecular weight distribution of the degradated wheat straw lignin in different O₃/H₂O₂ oxidizing conditions, it was found that comparing the ozone oxidizing without H₂O₂, the proportion of the molecular weight greater than 2000 of insoluble lignin increased obviously, at the same time, the degree of homogenization and molecular weight distribution were further improved. In the optimum conditions of O₃/H₂O₂ oxidizing and Na₂SO₃ dosage was 5 mmol/g, the pulp had the highest flowage value which was up to 153 mm. At the same time, the surface activity was good.更多还原