The key role of lignin and hemicelluloses content on final properties of lignocellulosic nanofibers

EHMAN, N.; LOURENÇCO A.; FELISSIA F.E.; FERREIRA P.J.T.; AREA M.C.

Sao Paulo

Congreso; 51º Congresso Internacional de Celulose e Papel - X Congresso Iberoamericano de Pesquisa em Celulose e Papel; 2018

ABTCP

The aim of this study was to highlight the key role of hemicellulose and lignin in lignocellulose nanofibers (LCNF) production and on the final properties of LCNF. Pulps with different chemical treatments were characterized to know the content of hemicelluloses and lignin in the sample, and pulp samples were treated with 0,8% and 1.6% TEMPO reactive in oxidative stage and then mechanically fibrillated using a colloidal grinder. Fibrillation time decreases with higher hemicelluloses and lignin content and TEMPO application, transmittance increase with hemicelluloses content but decreases when lignin content and TEMPO increase, and carboxyl groups content slightly decreases with lignin content but strongly increases with TEMPO application. Light transmittance correlates positively with the carboxyl groups content. There is a linear relationship between the values of turbidity and transmittance, which means that this first parameter could be an alternative method of the indirect measurement of the fibrillation degree. Zeta potential presents a positive correlation with lignin content. All values were lower than -30 mV, showing that particles in all suspensions tend to repel each other without any tendency to flocculate. A mean width of approximately 24.8 nm was quantified using AFM, similar to that obtained using a theoretical calculation.