碱润胀预处理对微晶纤维素质量的影响

Effect of alkali swelling pretreatment on the quality of microcrystalline cellulose

关键词:  碱处理  微晶纤维素  酸渗透速率  粒径分布

Key Words:alkali treatment  microcrystalline cellulose  acid permeation rate  particle size distribution

摘要:纤维素纤维酸水解制备微晶纤维素(Microcrystalline cellulose,MCC)时,因其复杂的聚集态结构,导致选择性酸水解时酸液渗透缓慢,酸水解反应在纤维素纤维细胞壁内的区域反应均匀性较差,从而对微晶纤维素质量产生影响。本研究通过采用NaOH溶液来对针叶木溶解浆进行有限润胀预处理,探究了碱预处理对酸水解产物微晶纤维素的质量影响。结果表明,最佳碱浓度预处理后MCC平均粒径由52.1μm降低至41.8μm,且粒径分布更加集中,MCC结晶度基本保持不变；碱处理对纤维素纤维及MCC化学结构和热稳定性无大的影响。

Abstract:When the microcrystalline cellulose is prepared by acid hydrolysis of the cellulose fiber, due to its complex aggregation structure, acid permeation is slow during selective acid hydrolysis, and acid hydrolysis reaction in the cell wall of cellulose fiber is less uniform, thereby affecting the quality of microcrystalline cellulose. In this study, NaOH solution was used to pretreat coniferous wood dissolved pulp with limited swelling, and the effect of alkali pretreatment on the quality of acid hydrolyzed product microcrystalline cellulose was investigated. The results showed that the average particle size of MCC decreased from 52.1μm to 41.8μm after pretreatment with the optimum alkali concentration, the particle size distribution was more concentrated, and the MCC crystallinity remained basically unchanged. Alkali treatment has no major influence on the chemical structure and thermal stability of cellulose fibers and MCC.