杨木CTMP碱性H2O2漂白中糖醛酸溶出的研究

Releasing of Uronic Acids in Alkaline Peroxide Bleaching of Aspen CTMP

关键词:  杨木CTMP  糖醛酸  碱性H₂O₂漂白

Key Words:aspen CTMP  uronic acids  alkaline peroxide bleaching

摘要:研究了杨木CTMP碱性H₂O₂漂白过程中漂白工艺对糖醛酸溶出的影响。结果表明，糖醛酸的溶出主要受体系碱度的影响。高碱度下，H₂O₂的加入会在一定程度上阻碍糖醛酸的溶出；高温(如高于80℃)会加剧糖醛酸的溶出；一定温度下，糖醛酸的溶出主要在反应初期阶段较快速。正交实验结果表明，影响糖醛酸溶出的漂白工艺条件依次为NaOH用量、温度、H₂O₂用量、浆浓、反应时间。

Abstract:Some dissolved and colloidal substances (DCS) tend to release during the alkline hydrogen peroxide bleaching of mechanical pulp, and the anionic groups (AGs) in DCS are mainly uronic acids. In this paper, the aspen CTMP were bleached with alkaline hydrogen peroxide under different conditions, and the content of uronic acids in the resultant DCS was determined by spectrophotometric method. The results showed that the amount of uronic acids dissolved was mainly affected by the alkalinity of the system; Peroxide could obstruct the release of the uronic acids under high alkalinity. High reaction temperature (e.g. above 80℃) could result in a significant increase of the content of uronic acids. The results of orthogonal experiments indicated that factors affecting the uronic acids relasase were the dosage of NaOH, temperature, dosage of H₂O₂, consistency of pulp and reaction time in order.