TEMPO-Mediated Oxidation of Norway Spruce and Eucalyptus Pulps: Preparation and Characterization of Nanofibers and Nanofiber Dispersions

• Published in: Journal of polymers and the environment Vol. 21; no. 1; pp. 207 - 214
• Main Authors: Rodionova, Galina, Saito, Tsuguyuki, Lenes, Marianne, Eriksen, Øyvind, Gregersen, Øyvind, Kuramae, Ryota, Isogai, Akira
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.03.2013; Springer; Springer Nature B.V
• Subjects: Aldehydes; Applied sciences; Cellulose; Cellulose and derivatives; Cellulose fibers; Chemistry; Chemistry and Materials Science; Dispersions; Environmental Chemistry; Environmental Engineering/Biotechnology; Eucalyptus; Exact sciences and technology; Hardwoods; Industrial Chemistry/Chemical Engineering; Materials Science; Nanofibers; Nanomaterials; Natural polymers; Original Paper; Oxidation; Physicochemistry of polymers; Pine trees; Polymer Sciences; Polymers; Sodium; Sodium bromides; Softwoods; Trees; TEMPO-mediated oxidation; Carboxylate contents; Softwood; Hardwood; Cellulose nanofibers; Transparency; Molecular structure; Cellulose; Paper pulp; Nanofiber; Experimental study; Structure processing relationship; Sodium Hypochlorites; Chemical modification; Functionality; Cellulose(carboxy); Morphology; Piperidine derivatives; Carboxyl group; Oxidation; Aqueous dispersion
• ISSN: 1566-2543; 1572-8919; 1572-8900
• DOI: 10.1007/s10924-012-0483-9

This study deals with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-mediated oxidation of cellulose. Softwood and hardwood pulp fibers were suspended in water and oxidized to various extents at pH 10 and 22 °C using sodium hypochlorite in the presence of TEMPO radical and sodium bromide. This reaction system is known to be the most efficient one for the introduction of both surface carboxyl and aldehyde groups. Important relationships between formation of these functional groups and the fibrillation yield, light transmittance of the water dispersions and degree of polymerization of the oxidized softwood and hardwood pulps were established in the present study. A birefringence test confirmed the presence of nanofibers which according to atomic force microscopy analyses had diameters in the 1.6–3.8 nm range.