Effect of lignin on the morphological, rheological, and dielectric characteristics of lignocellulose nanofibrils from Pinus radiata

Abstract

[EN] Lignocellulose nanofibrils (LCNFs) are a nanomaterial composed mainly of cellulose, hemicellulose, and lignin. The lignin and its chemical modification in fibrils affect the production process and the morphological and surface characteristics of the LCNFs. These differences in the LCNFs produce different rheological and dielectric properties, which are key to the potential uses of the nanomaterial. This work aims to understand the effect of lignin on the production process and characteristics of LCNFs. A smaller amount of lignin favored the nanofibril production process, producing fibrils with smaller widths and the same apparent length distribution (15 passes). Regarding the rheology of LCNFs, native lignin in the fibrils produced a minor resistance to flow. On the other hand, oxidized lignin had stronger and hydrated flocs of larger size due to higher specific surface area or surface charge of fibrils. Finally, the dielectric properties of LCNFs decreased with increasing crosslinking structures and increased with increasing polar groups.