摘要
以杨木浆板纤维素为原料,通过单因素实验和正交实验,采取预处理工艺和三次碱化两次醚化工艺,并采用超声波和高速剪切分散等辅助手段,制备高取代度羧甲基木质纤维素钠。结果表明,预处理工艺:70℃下用10%NaOH溶液(固液比1∶40g/mL)浸泡搅拌90min;碱化醚化工艺:室温下首次碱化时间为60min,50℃下第二次碱化和首次醚化反应时间为30min,最后在70℃下第三次碱化和第二次醚化反应时间为90min,氯乙酸钠用量∶NaOH用量∶碱化纤维素用量=1.4∶1∶1(质量比);经过预处理和三次碱化两次醚化,产品取代度达到1.33,黏度为404.0mPa·s。在碱化醚化过程中,在室温碱化后用高速剪切分散处理10min(A档),第一次醚化后用超声波处理10min(49kHz,功率99%),最终产品的取代度由1.33升高到1.48,但黏度由404.0mPa·s下降到181.9mPa·s。
Wood pulp board cellulose is used as raw material,pretreatment technology and three times of alkalization and twice of etherification processes are adopted through single factor experiment and orthogonal experiment,and ultrasonic and high-speed shear dispersion are used as auxiliary methods.The preparation of high substitution sodium carboxymethyl lignocellulose were determined,and the results showed that the pretreatment process was that soaking and stirring lasted for 90 min with 10% sodium hydroxide solution (solid-liquid ratio 1 ∶40) at 70 ℃,and the alkalization and etherification process was that the first time of alkalization lasted for 60 min at room temperature,and the second time of alkalization and the first time of etherification reaction lasted for 30 min at 50 ℃,the third time of alkalization and the second time of therification reaction lasted for 90 min at 70 ℃,and the dosage ratio of sodium chloroacetate to sodium hydroxide to alkaline cellulose was 1.4 ∶1 ∶1,after pretreatment and three times of alkalizations and twice of etherification,the degree of substitution is 1.33 and the viscosity is 404.0 mPa·s.In the process of alkalization and etherification,when the high-speed shear dispersion was used for 10 min (Grade A) after alkalization at room temperature,and ultrasonic treatment was used for 10 min (49 kHz,power 99%) after the first time of etherification,the degree of substitution of the final product increased from 1.33 to 1.48,but the viscosity decreased from 404.0 mPa·s to 181.9 mPa·s.
作者
陈惠芳
蒋新元
孟浩亮
陈介南
许琼文
CHEN Hui-fang;JIANG Xin-yuan;MENG Hao-liang;CHEN Jie-nan;XU Qiong-wen(School of Materials Science and Engineering,Central South University of Forestry and Technology,Changsha 410004,China;Research Centre of Engineering and Technology for Conversion ofWoody Biomass in Hunan,Changsha 410004,China)
出处
《应用化工》
CAS
CSCD
北大核心
2019年第7期1587-1591,共5页
Applied Chemical Industry
基金
湖南省科技重大专项(2017NK1013)
关键词
木质纤维素
羧甲基纤维素钠
碱化
醚化
取代度
lignocellulose
sodium carboxymethyl cellulose
alkalization
etherification
degree of substitution
