Cellulose degradation in alkaline media upon acidic pretreatment and stabilisation.

Carbohydr Polym

Department of Forest Products Technology, Aalto University School of Chemical Technology, P.O. Box 16300, Vuorimiehentie 1, Espoo, FI-00076 Aalto, Finland.

Published: January 2014

The present study reports on a revised kinetic model for alkaline degradation of cellulose accounting for primary peeling/stopping reactions as well as for alkaline hydrolysis followed by secondary peeling. Oxalic acid pretreated cotton linters was utilised as the model substrate for the prehydrolysis-soda anthraquinone process. The main emphasis was investigating the effect of end-group stabilising additives such as sodium borohydride (BH), anthraquinone (AQ), and anthraquinone-2-sulphonic acid sodium salt (AQS) on the rates of the yield loss reactions. BH and AQS ensured a cellulose yield gain of 13% and 11%, respectively, compared to the reference. Both stabilisation agents decreased the content of the reducing end groups in the samples, while in the case of AQS stabilisation a 25% increase in carboxyl group content compared to the reference was also observed. As expected, the addition of end group stabilisers resulted in a significant decrease in the peeling-to-stopping rate constants ratio.

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http://dx.doi.org/10.1016/j.carbpol.2013.01.093DOI Listing

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