Cellulose nanocrystals from forest residues en reinforcing agentes for composites: A study from macro- nano-dimensiones

This study investigates for the first time the feasibility of extracting cellulose nanocrystals (CNCs) fromsoftwood forestry logging residues (woody chips, branches and pine needles), with an obtained gravimet-ric yield of over 13%. Compared with the other residues, woody chips rendered a higher yield of bleachedcellulosic fibers with higher hemicellulose, pectin and lignin content, longer diameter, and lower crys-tallinity and thermal stability. The isolation of CNCs from these bleached cellulosic fibers was verifiedby the removal of most of their amorphous components, the increase in the crystallinity index, and thenano-dimensions of the individual crystals. The differences in the physico-chemical properties of thefibers extracted from the three logging residues resulted in CNCs with specific physico-chemical prop-erties. The potential of using the resulting CNCs as reinforcements in nanocomposites was discussed interms of aspect ratio, crystallinity and thermal stability.