Cellulose oxidation by Laccase-TEMPO treatments. (10th February 2017)

• Record Type: Journal Article
• Authors: Quintana, Elisabet; Roncero, M. Blanca; Vidal, Teresa; Valls, Cristina
• Is Part Of: Carbohydrate polymers. Volume 157(2017)
• Page Start: 1488
• Page End: 1495
• Publication Date: 2017-02-10
• Subjects: 2, 2, 6, 6-tetramethyl-1-piperidinyloxy (TEMPO) (PubChem CID: 2724126) -- 2, 2-azinobis(3-thylbenzothiazoline-6-sulfonic acid) (ABTS) (PubChem CID: 6871216); Carboxyl groups -- Dissolving pulp -- Hemiacetal linkage -- Laccase -- TEMPO; Polysaccharides -- Periodicals; Polysaccharides -- Periodicals; Polysaccharides -- Périodiques; Electronic journals; 547.78
• DOI: 10.1016/j.carbpol.2016.11.033
• Languages: English
• ISSNs: 0144-8617

Abstract

Highlights: Laccase-TEMPO treatments provided carbonyl and carboxyl groups on dissolving pulp. Laccase-TEMPO treatment conducted in presence of oxygen developed wet strength. A pre-refining step led to hemiacetal covalent linkages and improved wet strength. Higher wet-zero span strength correlated highly with presence of hemiacetal linkages. Laccase-TEMPO caused degradation but hemiacetal linkages hindered Fock solubility. Abstract: In this work, laccase-TEMPO (Lac-T) treatments were applied to bleached commercial dissolving pulp in order to introduce carbonyl and carboxyl groups, which were found to improve dry and wet strength-related properties. Also the solubility behavior towards xanthate reactions was assessed. The effect of a refining step (R) before the oxidative treatment, the absence or presence of oxygen pressure, TEMPO dose (2 or 8% oven dried pulp) and reaction time (8 or 20 h) were thoroughly examined. Treatments conducted in the presence of oxygen pressure exhibited greater amount of functional groups. Introducing a pre-refining treatment resulted in similar functional groups but higher wet strength was achieved. Specifically, a high W/D strength ratio was observed, indicating that wet strength-related property was satisfactorily developed. Besides the fact that all Lac-T treatments caused severe cellulose degradation, no fiber strength loss was detected. In fact, all oxidized samples presented higher Wet Zero-Span Tensile Strength, mainly in R+ Lac-T (O2 ) sample, which suggested the formation of hemiacetal linkages between the new introduced aldehyde groups and available free hydroxyl groups resulting from fibrillation.