蓝桉CTMP过氧化氢漂白难点分析

Preliminary Study on the Reason of the Difficulty of E.Globules CTMP to Be Bleached to High Brightness by H_2O_2

分析了蓝桉化学热磨机械浆(CTMP)在H_2O_2置换漂白过程中木素中邻醌和甲氧基等功能性基团的变化。对用H_2O_2难于将蓝桉CTMP漂白至较高白度的原因进行了初步探索。结果表明,漂后浆木素中仍有相当数量的邻醌存在,无法用H_2O_2完全有效去除。漂后浆木素中甲氧基含量增加,降低了木素的反应活性,不利于H_2O_2对木素发色基团的脱除。

The reason of the difficulty of E. globules CTMP to be bleached to high brightness by H2O2 was preliminary studied in this paper. The results showed that the amount of methoxyl in lignin increases and the reaction activity of the lignin decreases due to much more guaiacyl lignin is dissolved than syringyl lignin during H2O2 displacement bleaching of E. globulus CTMP. This is unfavorable to the reaction between H2O2 and lignin chromophores. Meanwhile, considerable amount of o-quinone exists in the lignin of bleached pulp yet and cannot be removed out fully and effectively by H2O2 is one of the important reasons of why high-yield pulp cannot be bleached to high brightness only by H2O2.