碱化预处理对高压射流超微细化纤维素的影响  

Effect of alkali pretreatment on ultra micronization of cellulose by high pressure jet

作　　者：刘婷[1] 张绍英[1] 吴雪[2] 刘斌[2] LIU Ting;ZHANG Shao-ying;WU Xue;LIU Bin(College of Engineering,China Agricultural University,Beijing 100083,China;College of Material and Mechanical Engineering,Beijing Technology and Business University,Beijing 100048,China)

机构地区：[1]中国农业大学工学院,北京100083 [2]北京工商大学材料与机械工程学院,北京100048

出　　处：《食品与机械》2020年第1期36-41,共6页Food and Machinery

基　　金：国家重点研发计划资助项目(编号：2016YFD0400305)

摘　　要：为了揭示纤维素超微细化处理后的结构和物性变化,利用高压射流技术对两种纤维素微粉(原样、碱处理)悬液进行了湿法破碎,检测了产物微观形态、粒径分布、比表面积以及结晶度的变化。结果表明,高压射流处理(130 MPa,100μm单孔阀,4次)可使原样和碱化(10%NaOH,70℃,1 h)后的纤维素微束直径由原料的5.0〜50.0 pm分别降至0.5〜5.0μm和0.1〜1.0μm,微束长度由原料的20.0〜200.0降至1.0〜10.0粒径分布曲线峰值可由原料的158.0μm降至10.0μm左右;比表面积分别提高3.0倍和5.5倍。碱化处理可降低纤维素无定形区的强度进而降低纤维素的破碎能。纤维素原样经高压射流后结晶度改变不明显;碱化预处理后高压射流处理产物的结晶度小幅度(10%)下降。碱化预处理增强了高压射流处理纤维素原料的微细化程度。;In order to reveal the change of cellulose structure and physical property caused by ultra micronization,cellulose power was treated through different concentrations of sodium hydroxide and then broken by using high pressure jet.The microstructure,size and physical properties of microfabrication were explored.After pretreatment with 10%NaOH solution(70℃,1 h)and high pressure jet treatment,the diameter of the crude microfabrication decreases from 5.0〜50.0 pm to 0.1〜1.0μm,and the length decreases from 20.0〜200.0 to 1.0〜10.0 The peak value of cellulose particle size distribution curve was reduced from 158.0μm to 10.0μm.The specific surface area was improved by 3.0-5.5 times.The results indicated that the swell-ing of cellulose microfiber bundles after alkali pretreatment could reduce the mechanical properties of the celkilose,and its particle size decreased significantly by the spraying of high pressure jet.XRD results showed that there was no obvious change in the crystallinity and thermal stability after high pressure jet.However,the crystallinity of cellulose decreased 10% after alkalization.Alkali pretreatment improved the micronization degree of cellulose by high pressure jet.

关 键 词：纤维素 高压射流 微细化 比表面积 结晶度 

分 类 号：TS201.2[轻工技术与工程—食品科学]