Juho Antti Sirviö, Anu Maria Kantola, Ari Ämmälä, Cellulose nanofibers from nonbleached and hydrogen peroxide bleached acidic thiourea treated sawdust, Journal of Cleaner Production, Volume 423, 2023, 138824, ISSN 0959-6526, https://doi.org/10.1016/j.jclepro.2023.138824
Cellulose nanofibers from nonbleached and hydrogen peroxide bleached acidic thiourea treated sawdust
|Author:||Sirviö, Juho Antti1; Kantola, Anu Maria2; Ämmälä, Ari1|
1Fibre and Particle Engineering Research Unit, University of Oulu, P.O. Box 4300, 90014, Oulu, Finland
2NMR Research Unit, University of Oulu, P.O.Box 3000, FIN-90014, Oulu, Finland
|Online Access:||PDF Full Text (PDF, 4.4 MB)|
|Persistent link:|| http://urn.fi/urn:nbn:fi-fe20231031142049
|Publish Date:|| 2023-10-31
Here a single-step acidic thiourea delignification without and with sequential hydrogen peroxide bleaching were used as a pre-treatment for producing low-lignin-containing cellulose nanofibers (LCNF) and bleached cellulose nanofibers (BCNF), respectively. Without bleaching, LCNF contained 7 wt% lignin, resulting in a slightly yellowish color in both the water dispersion and film. Despite low gravimetric yield of nanosize fibers, 23 wt% after microfluidization, the LCNF films exhibited notable mechanical strength, with a tensile strength of 174 MPa and a modulus of 11 GPa. Upon introducing an additional bleaching step, the color was eliminated, reducing the lignin content to 3 wt%. This adjustment also led to a significant increase in the gravimetric yield of nanofibers, reaching 78 wt%. The BCNF films demonstrated even higher mechanical performance, with a tensile strength of 207 MPa and a modulus of 12 GPa. LCNF film exhibited a higher contact angle (≈70°) than BCNF (≈60°), presumably due to the higher lignin content of the nonbleached pulp. Furthermore, hot pressing of the films at 150 °C for 18 min substantially enhanced the wet strength of the films by over 50%, attributed to the residual lignin.
Journal of cleaner production
|Type of Publication:||
A1 Journal article – refereed
|Field of Science:||
216 Materials engineering
Part of the work was carried out with the support of the Centre for Material Analysis, University of Oulu, Finland.
© 2023 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).