弱碱性过氧化氢漂白对杨木CTMP中碳水化合物和木质素的影响

Effect of Weak Alkaline Hydrogen Peroxide Bleaching on Carbohydrates and Lignin in Poplar CTMP

关键词:  杨木CTMP  H₂O₂漂白  MgO  碳水化合物  木质素  纸浆性能

Key Words:poplar CTMP  H₂O₂ bleaching  MgO  carbohydrates  lignin  pulp properties

摘要:本研究探讨了杨木CTMP碱性过氧化氢漂白中，MgO取代NaOH比例和漂白时间对杨木CTMP中碳水化合物和木质素含量及纸浆性能的影响。结果表明，在漂白初期，杨木CTMP中的碳水化合物和木质素溶出较快，漂白后期溶出的速率较缓慢。随MgO取代NaOH比例的增加，杨木CTMP的漂白得率显著提高，漂白浆中的碳水化合物和木质素含量明显增加。与对照样（以NaOH为碱源）相比，漂白时间90 min，MgO取代NaOH比例为75%时，漂白浆中的综纤维素和木质素含量分别达67.60%和23.09%；浆张的松厚度从2.09 cm³/g上升到2.21 cm³/g，增加了5.74%；白度略微下降；浆张的抗张指数和撕裂指数分别下降了14.16%和14.32%，达40.6 N·m/g和3.47 mN·m²/g。

Abstract:In this study， the effects of MgO substitution ratio for NaOH and bleaching time on the carbohydrates and lignin content and properties of poplar CTMP were investigated. The results showed that the carbohydrates and lignin in poplar CTMP would be dissolved quickly in the early stage of bleaching， and slowly in the later stage of bleaching. With the substitution ratio of NaOH with MgO increased， the bleaching yield of the poplar CTMP and the content of carbohydrates and lignin in the bleached pulp increased significantly. Compared to the control sample （NaOH as the alkali source）， when the MgO substitution ratio for NaOH was 75%， and bleaching time was 90 min， respectively， the contents of holocellulose and lignin in the bleached pulp reached 67.60% and 23.09%， respectively. Moreover， the bulk reached 2.21 cm³/g from 2.09 cm³/g with an increase of 5.74%， and the brightness decreased slightly. Meanwhile， the tensile index and tear index were 40.6 N·m/g and 3.47 mN·m²/g with a decrease of 14.16% and 14.32%， respectively.