Viscometric determination of dialdehyde content in periodate oxycellulose. Part I. Methodology

Periodate oxycellulose was subjected to alkaline hydrolysis at room temperature in both homogeneous (cupriethylenediamine) and heterogeneous ( sodium hydroxide) medium, and the degradation kinetics was followed for nearly three months. By comparing the obtained results with the degradation kinetics of both hydrocellulose and periodate oxycellulose reduced with tert-butylamine borane, it was demonstrated that the beta-alkoxy fragmentation of oxidised sites is a very fast reaction, which reaches completeness during the preparation of samples for viscometric analyses. The subsequent degradation is due to other mechanisms, such as autoxidation and peeling. A comparison between the degrees of polymerisation of periodate oxycellulose before and after its reduction allows the quantitative determination of dialdehyde groups, without the interference of reducing end groups. Although this technique might not be valid for other kinds of oxycellulose, it supplies a simple and fast method for the analysis of mildly oxidised cellulose.