When: Friday 3rd May 2019, at 12pm-1pm
Where: BioPRIA Building 59, 15 Alliance Lane, Clayton VIC 3800
Speaker: David Mendoza
ONE-SHOT TEMPO-PERIODATE OXIDATION OF NATIVE CELLULOSE
Oxidation of cellulose into carbonyl groups is essential for the functionalisation of (bio)molecules and introduction of surface charge density. There is also significant research interest on a large variety of functional products that can be obtained from cellulose oxidation depending on the type of cellulose, employed reagents, and conditions. Among the oxidation protocols, TEMPO-mediated and periodate oxidation reactions are considered to be the most popular, owing to their regioselectivity and efficiency and “green” conditions.
In this study, oxidation of native cellulose in the presence of TEMPO/NaClO/NaBr and sodium periodate in a one-shot reaction was investigated. Oxidised cellulose fibres were rigorously characterised in terms of mass yield, surface charge density, chemical structure and degree of polymerisation. Changes in crystallinity, crystal size and fibre morphology after TEMPO-periodate oxidation were also investigated. Moreover, the effects of periodate concentration on the properties of oxidised cellulose were also assessed.
Results showed that TEMPO-periodate reaction of native cellulose yielded highly-oxidised water-insoluble and water-soluble fractions. Spectroscopic analyses also revealed that only by combining TEMPO/NaClO/NaBr and sodium periodate simultaneously will result in the formation of tricarboxycellulose (TCC), a functional polyelectrolyte polymer. In addition, results suggest that the properties of oxidised cellulose are highly affected by the concentration of sodium periodate in the one-shot reaction.