Overview of Methods for the Direct Molar Mass Determination of Cellulose

Molecules

Josua Timotheus Oberlerchner²  Thomas Rosenau²  Antje Potthast¹ 

[1] Christian-Doppler Laboratory “Advanced Cellulose Chemistry and Analytics”, Division of Chemistry of Renewable Resources, Department of Chemistry, University of Natural Resources and Life Sciences Vienna, Muthgasse 18, A-1190 Vienna, Austria;

关键词: cellulose;    molar mass distribution;    molar mass average;    viscometry;    end group analysis;    osmometry;    ultracentrifuge;    size exclusion chromatography;    light scattering;    cello-oligomers;   

DOI  :  10.3390/molecules200610313

来源: mdpi

【 摘 要 】

The purpose of this article is to provide the reader with an overview of the methods used to determine the molecular weights of cellulose. Methods that employ direct dissolution of the cellulose polymer are described; hence methods for investigating the molecular weight of cellulose in derivatized states, such as ethers or esters, only form a minor part of this review. Many of the methods described are primarily of historical interest since they have no use in modern cellulose chemistry. However, older methods, such as osmometry or ultracentrifuge experiments, were the first analytical methods used in polymer chemistry and continue to serve as sources of fundamental information (such as the cellulose structure in solution). The first part of the paper reviews methods, either absolute or relative, for the estimation of average molecular weights. Regardless of an absolute or relative approach, the outcome is a molecular weight average (MWA). In the final section, coupling methods are described. The primary benefit of performing a pre-separation step on the molecules is the discovery of the molecular weight distribution (MWD). Here, size exclusion chromatography (SEC) is unquestionably the most powerful and most commonly-applied method in modern laboratories and industrial settings.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.