Skip to main content
Research article - Peer-reviewed, 2021

Comparison of tension wood and normal wood for oxidative nanofibrillation and network characteristics

Jonasson, Simon; Bunder, Anne; Das, Oisik; Niittyla, Totte; Oksman, Kristiina

Abstract

Cellulose nanofibrils (CNFs) are top-down nanomaterials obtainable from abundant lignocelluloses. Despite recent advances in processing technologies, the effects of variations in the lignocellulose structure and composition on CNF isolation and properties are poorly understood. In this study, we compared the isolation of CNFs from tension wood (TW) and normal wood (NW) from Populus tremula (aspen). The TW has a higher cellulose content, native cellulose fibrils with a larger crystalline diameter, and less lignin than the NW, making it an interesting material for CNF isolation. The wood powders were oxidized directly by 2,2,6,6-tetramethylpiperidin-1-oxyl, and the morphology and mechanical behaviors of the nanofibril suspensions and networks were characterized. The TW was more difficult to fibrillate by both chemical and mechanical means. Larger nanofibrils (5-10 nm) composed of 1.2 nm structures were present in the TW CNFs, whereas the NW samples contained more of thin (1.6 nm) structures, which also comprised 77% of the solid yield compared to the 33% for TW. This difference was reflected in the TW CNF networks as decreased transmittance (15% vs. 50%), higher degree of crystallinity (85.9% vs. 78.0%), doubled toughness (11 MJ/m(3)) and higher elongation at break (12%) compared to NW. The difference was ascribed to greater preservation of the hierarchical, more crystalline microfibril structure, combined with a more cellulose-rich network (84% vs. 70%). This knowledge of the processing, structure, and properties of CNFs can facilitate the breeding and design of wood feedstocks to meet the increasing demand for nanoscale renewable materials.[GRAPHICS].

Keywords

Cellulose nanofibril; Nanofibrillation; Fibril network; TEMPO oxidation; Tension wood; Wood properties

Published in

Cellulose
2021, volume: 28, number: 2, pages: 1085-1104
Publisher: SPRINGER

Authors' information

Jonasson, Simon
Lulea University of Technology
Swedish University of Agricultural Sciences, Department of Forest Genetics and Plant Physiology
Das, Oisik
Lulea University of Technology
Swedish University of Agricultural Sciences, Department of Forest Genetics and Plant Physiology
Oksman, Kristiina
University of Toronto

UKÄ Subject classification

Wood Science

Publication Identifiers

DOI: https://doi.org/10.1007/s10570-020-03556-1

URI (permanent link to this page)

https://res.slu.se/id/publ/109245