How alkaline solvents in viscosity measurements affect data for oxidatively damaged celluloses. Cuoxam and Cadoxen. (15th July 2020) - Zaccaron, Sara
Graphical abstract: Highlights: Solvent-induced degradation depends on both the type of pulp and oxidant. Hemicellulose-containing pulps more damaged; greater molar mass underestimation. Amount and position of oxidized groups along the chains affect degradation. Solvent-induced degradation increases with increasing degree of oxidation. Lability of peroxide-oxidized celluloses greater than hypochlorite-oxidized ones. Abstract: The effect of the degradation induced by the solvents for cellulose cuoxam and cadoxen and its dependency on the nature of the carbonyls in oxidatively-damaged cellulosics was investigated by combining a novel approach of sample regeneration and gel permeation chromatography coupled with carbonyl-selective labelling for reliable molecular characterization. The type of cellulosic pulp, degree and mode of oxidation and dissolution time were considered. Results show that the main discriminating factors in determining the degradation of oxidatively-damaged celluloses in alkaline dissolving media are: (1) the type of pulp, i.e. hemicellulose-containing pulps are more severely compromised; (2) of particular relevance, the prior oxidation mechanism, meaning not only the amount of oxidized moieties (greater oxidation, greater solvent-induced damage) but also their position on the chains (i.e. peroxide-oxidized cellulose is more unstable than hypochlorite-oxidized cellulose).