title: Cellulose degradation in alkaline media upon acidic pretreatment and stabilisation.
abstract: 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.
authors.affiliation: Department of Forest Products Technology, Aalto University School of Chemical Technology, P.O. Box 16300, Vuorimiehentie 1, Espoo, FI-00076 Aalto, Finland.
authors.forename: Lidia
authors.initials: L
authors.lastname: Testova
authors.forename: Kaarlo
authors.initials: K
authors.lastname: Nieminen
authors.forename: Paavo A
authors.initials: PA
authors.lastname: Penttilä
authors.forename: Ritva
authors.initials: R
authors.lastname: Serimaa
authors.forename: Antje
authors.initials: A
authors.lastname: Potthast
authors.forename: Herbert
authors.initials: H
authors.lastname: Sixta
mesh_terms: D000880:Anthraquinones / Q000737:chemistry; D001894:Borohydrides / Q000737:chemistry; D002482:Cellulose / Q000737:chemistry*; D004355:Drug Stability; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D019815:Oxalic Acid / Q000737:chemistry; D010084:Oxidation-Reduction
chemical_list: D000880:Anthraquinones; D001894:Borohydrides; C023554:anthraquinone sulfonate; C025364:sodium borohydride; D002482:Cellulose; D019815:Oxalic Acid
keywords: 2,2′-bicinchoninate; AQ; AQS; Acidic pretreatment; Alkaline degradation; BCA; BH; CL; Cellulose; Cotton linters; OA; REG; Stabilisation; Yield loss kinetics; anthraquinone; anthraquinone-2-sulphonic acid sodium salt; cotton linters; oxalic acid; reducing end group; sodium borohydride