Activation of TEMPO by ClO <subscript>2</subscript> for oxidation of cellulose by hypochlorite-Fundamental and practical aspects of the catalytic system.
In: Carbohydrate polymers, Jg. 174 (2017-10-15), S. 524
Online
academicJournal
Zugriff:
Bromide-free TEMPO-catalyzed oxidation of the primary alcohols by sodium hypochlorite (NaOCl) does not proceed without a prior activation of the catalyst. Here were demonstrate an immediate in situ activation of the catalyst with an equimolar addition of chlorine dioxide (ClO 2 ) relative to TEMPO. Sodium bromide (NaBr) had a similar role in activating the catalyst although NaBr was needed in excess and the activation took several minutes depending on the dosage of NaBr. The activation method, or the concentration of NaBr, did not affect the bulk oxidation rate. The selectivity of the ClO 2 initiated oxidation remained high up to NaOCl addition of 3mol/kg bleached birch kraft pulp after which additional loss in yield and depolymerization of cellulose were emphasized with negligible increase in carboxylate content. A carboxylate content of 0.8-1mol/kg, sufficient for easy mechanical fibrillation of the pulp, was achieved under mild conditions with NaOCl addition of 2-2.5mol/kg pulp.
(Copyright © 2017 Elsevier Ltd. All rights reserved.)
Titel: |
Activation of TEMPO by ClO <subscript>2</subscript> for oxidation of cellulose by hypochlorite-Fundamental and practical aspects of the catalytic system.
|
---|---|
Autor/in / Beteiligte Person: | Pääkkönen, T ; Pönni, R ; Dou, J ; Nuopponen, M ; Vuorinen, T |
Link: | |
Zeitschrift: | Carbohydrate polymers, Jg. 174 (2017-10-15), S. 524 |
Veröffentlichung: | <1992-> : Barking : Elsevier Applied Science Publishers ; <i>Original Publication</i>: London [Eng.] : Applied Science Publishers, c1981-, 2017 |
Medientyp: | academicJournal |
ISSN: | 1879-1344 (electronic) |
DOI: | 10.1016/j.carbpol.2017.06.117 |
Sonstiges: |
|