Molecules 2015, 20, 10313-10341; doi:10.3390/molecules200610313 OPEN ACCESS molecules ISSN 1420-3049 www.mdpi.com/journal/molecules Review Overview of Methods for the Direct Molar Mass Determination of Cellulose Josua Timotheus Oberlerchner, Thomas Rosenau and Antje Potthast * 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; E-Mails:
[email protected] (J.T.O.);
[email protected] (T.R.) * Author to whom correspondence should be addressed; E-Mail:
[email protected]; Tel.: +43-1-47654-6454; Fax: +43-1-47654-6059. Academic Editor: Jun Araki Received: 10 March 2015 / Accepted: 27 May 2015 / Published: 4 June 2015 Abstract: 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.