Journal of South China University of Technology (Natural Science Edition) ›› 2011, Vol. 39 ›› Issue (1): 58-62.doi: 10.3969/j.issn.1000-565X.2011.01.011

• Electronics, Communication & Automation Technology • Previous Articles     Next Articles

UV-Based Rapid Determination of Degree of Substitution of CMC with High Substitution

Ye Jun1,2 Zhang Yan-xing1,3 Xiong Jian2   

  1. 1. The south China university of technology of the pulp and paper engineering state key laboratory, guangdong guangzhou 510640; 2. South China university of technology, light industry and food institute, guangdong guangzhou 510640; 3. Guangdong paper institute, guangdong guangzhou 51030
  • Received:2010-05-12 Revised:2010-06-21 Online:2011-01-25 Published:2010-12-01
  • Contact: 熊犍(1965一)，男，博士，教授，主要从事纤维素及其它天然高分子物质结构与性能的研究 E-mail:lcjxiong@scut.edu.cn
  • About author:叶君(1963一)，女，博士，教授，主要从事植物资源化学研究
  • Supported by:

    国家“973”计划项目(2010CB732201)；国家自然科学基金资助项目(51043011)

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Abstract:

Proposed in this paper is a UV-based method to rapidly determine the degree of substitution（DS） of carboxymethyl cellulose（CMC） with high substitution.In this method,a curve of the UV absorbance of CMC-Cu（Ⅱ） solution versus the volume of dilute copper sulfate solution is obtained via the reaction CMC and Cu（Ⅱ）,which is divided into three regions,of which regionⅠ defined by Lambert-Beer＇s law corresponds to the stoichiometrical reaction of the carboxyl groups on CMC chain with Cu（Ⅱ） ions.Then,by fitting the curve in region Ⅰ,a straight line is obtained.When the square of correlation coefficient is more than 0.990,the DS of CMC can be calculated according to the volume of dilute copper sulfate solution at the intersection with maximum absorbance.The proposed method,which is of the advantages of rapidity,simplicity and is of small quantity of sample involved,is accurate in determining the DS of CMC with a DS higher than 0.80.As compared with the national standard method,the error of the proposed method ranges from 1.7% to 3.5% only.

Key words: carboxymethyl cellulose, degree of substitution, Cu(Ⅱ) ions, UV spectrophotometry