粉单竹木素-碳水化合物复合体在APMP制浆过程中的变化规律

Study on the Change Law of Pinle Single Bamboo Lignin-Carbohydrate Complex During APMP Pulping

关键词:  粉单竹  LCC  高得率浆  APMP  木素

Key Words:pink single bamboo  LCC  high yield pulp  APMP  lignin

摘要:本课题主要研究了粉单竹木素-碳水化合物复合体（LCC）在碱性过氧化氢机械法制浆（APMP）（包括制浆和漂白）过程中的结构变化规律。结果表明，未漂白APMP浆LCC提取率增加，绝对质量增加约2.6倍，LCC中木素与半纤维素的连接增加，木素的质量比从竹片7.29%增加为9.04%，葡萄糖质量比大幅下降。漂白后受木素和半纤维素溶出的影响，LCC提取率下降，绝对质量减少，LCC中的木素质量比提高至25.07%；漂白后的LCC分子发生部分的碎解和重组，分子质量分布出现明显的“分峰”，多分散性增加1倍，分子质量减少。在粉单竹APMP制浆过程中，LCC对木素的保留作用会阻碍浆料白度的提高并加速返黄。

Abstract:In this paper， the structural changes of lignin-carbohydrate complex （LCC） in alkaline hydrogen peroxide mechanical pulping （APMP） （including pulping and bleaching） were studied. The results showed that the extraction rate of LCC increased after refining， the absolute mass increased by about 2.6 times， the connection between lignin and hemicellulose in LCC increased， the mass ratio of lignin increased from 7.29% to 9.04%， and the mass ratio of glucose decreased significantly. After bleaching， LCC was affected by the dissolution of lignin and hemicellulose， the extraction rate and absolute quality decreased， and the mass ratio of lignin in LCC increased to 25.07%. The bleached LCC molecules would partially disintegrate and recombine， and the molecular weight distribution would appear obvious “peak separation”， the polydispersity would be doubled， and the molecular weight would decrease. During APMP pulping process， the retention of lignin by LCC would hinder the improvement of pulp brightness and accelerate the yellowing.