摘要
用电位滴定法实验测定异丙醇－水体系内醇与水不同比例下生成的羧甲基纤维素（ＣＭＣ）完全酶解及酸解后的还原端基数和其酸解速率，研究溶剂组成对ＣＭＣ取代基均一性的影响．发现在异丙醇含量为７５％～９５％范围内，随异丙醇用量增大，生成的ＣＭＣ取代度升高，取代基分布均一性变好，表现为取代链段长度Ｌｓｎ变长．而未取代ＬＧｍ变短，且Ｌｓｎ／（Ｌｓｎ＋ＬＧｍ）也增大，在Ｓｎ中夹杂的未取代葡萄糖单元（ＡＧＵ）数目也降低，ＣＭＣ表现出很好的耐酸性．
By potentiometry, the number of reduced terminal group of carboxymethylcellulose (CMC) after full enzymolysis or acidolysis has been experimentally determined, which was produced in an i-propanol water system with different proportions of alcohol to water. The effect of proportions of isopropanol to water on the equipartition of the substituting group of CMC has been studied. When the i-propanol content changed from 70% to 95%, it was found that the degree of substitution of CMC increases, the length of substituted segments Lsn becomes long while unsubstituted segments LGm becomes short, the value of Lsn/(Lsn+LGm) also Borninl952,male,seniorengineer·increases, the number of the unsubstituted anhydroglucose unit (AGU) in substituted segments sn decreases and acid resistance of CMC becomes strong. These show that the equipartition of the substituting group becomes better while the concentration of i-propanol increases.
出处
《天津大学学报》
CSCD
1996年第3期457-459,共3页
Journal of Tianjin University(Science and Technology)
关键词
羧甲基纤维素
取代基分布
异丙醇
水
CMC
distribution of substituting group
i-propanol
anhydroglucose unit
