酸水解和酶水解对纤维形态结构的影响研究

Comparative Study of Two Methods to Prepare Hydrolyzed Cellulose

关键词:  酸水解纤维素  酶水解纤维素  聚合度  粒径  形态

Key Words:acid hydrolyzed cellulose  enzymatic hydrolyzed cellulose  degree of polymerization  particle size  morphology

摘要:分别采用盐酸和纤维素酶对漂白针叶木浆进行水解,制得酸水解纤维素和酶水解纤维素,通过分析比较水解后纤维素在聚合度、粒径、微观形态以及理化性能上的区别,研究这两种方法制备的纤维素在形态、结构、性能上的差异。结果表明，漂白针叶木浆经盐酸在高温下水解1 h,纤维素聚合度下降到200左右,纤维平均长度下降到0.1～0.2 mm,经机械粉碎后呈椭圆形颗粒状,平均粒径27.49 μm；漂白针叶木浆经纤维素酶水解24 h后,纤维素聚合度降低到700左右,纤维平均长度也下降到0.1～0.2 mm,经机械粉碎后呈棒状颗粒,平均粒径38.77 μm。酸水解纤维素较酶水解纤维素具有较大的表观密度、持水力以及较好的流动性。

Abstract:Dilute hydrochloric acid and cellulase were applied to hydrolyze bleached softwood fiber respectively and acid hydrolyzed cellulose and enzymatic hydrolyzed cellulose were prepared. By analyzing and comparing the differences in the degree of polymerization（DP）， particle size， morphology physical and chemical properties of the cellulose(fiber） after hydrolysis by these two methods respectively， differences of enzymatic hydrolyzed cellulose and acid hydrolyzed cellulose in morphology， structure and properties were studied. The results showed that while the bleached softwood fiber was hydrolyzed by dilute hydrochloric acid for 1 h at high temperature， the DP of cellulose down to the limit of about 200， average fiber length down to 0.1～ 0.2 mm; it was oval particles with an average size of 27.49 μm after mechanical grinding. While the bleached softwood fiber was hydrolyzed by cellulase for 24 h， cellulose DP reduced to the limit of 700， average fiber length also down to 0.1～ 0.2 mm; after mechanical grinding， it was rod particles with an average size of 38.77 μm. Compared with the enzymatic hydrolyzed cellulose， acid hydrolyzed cellulose had larger volume density， water-holding capacity and better flowability．