A low-cost environmentally friendly approach to isolate lignin containing micro and nanofibrillated cellulose from Eucalyptus globulus bark by steam explosion

Micro- and Nano-Fibrillated Cellulose (MNFC) have gained increasing attention due to their remarkable properties, but their production usually requires an intensive multi-step process. This study proposes to find a novel approach involving steam explosion for the production of lignin-containing micro- and nano-fibrillated cellulose (L-MNFC) using Eucalyptus globulus bark as a new lignocellulosic feedstock. Eucalyptus globulus bark was first pre-treated by steam explosion in alkaline conditions (200 degrees C, 8 min) or by soda cooking in a rotating autoclave (170 degrees C, 60 min), refined and then ground until gels formed. The chemical composition of the pulps was studied with ion chromatography and FTIR-ATR. The morphology of the products was studied with measurements of suspension turbidity and Morfi Neo, optical and atomic force microscopies. Nanopapers were produced from L-MNFC to investigate mechanical properties. Results obtained showed that steam explosion produced pulps with slightly higher lignin content (approximate to 9%), containing shorter fibers 400 him) and higher amounts of fines (approximate to 86%) compared to soda cooking (approximate to 5%, approximate to 560 mu m) and 66%, respectively). AFM images of SteamEx L-MNFC gels showed a web-like structure containing lignin nanoparticles. [GRAPHICS] .

Automated summary

This study proposes a novel approach of using steam explosion for the production of lignin-containing micro- and nano-fibrillated cellulose, using Eucalyptus globulus bark as the raw material. The results show that steam explosion produces pulps with higher lignin content, shorter fibers, and more fines.