Influence of different pulping processes, cold caustic extraction, and bleaching as common post-treatments on properties of produced lignocellulose nanocrystals (LCNCs) from bagasse.

Abstract

The influence of different pulping processes-soda, monoethanolamine, and Formacell-along with cold caustic extraction (CCE) and a bleaching sequence (DEpD) as post-treatments on the properties of lignocellulosic nanocrystals (LCNCs) was evaluated. LCNCs were produced through acid hydrolysis from the pulps. SEM and AFM analyses confirmed the successful production of LCNCs with dimensions under 100 nm. FT-IR analysis indicated the presence of lignin in the nanocrystals. X-ray diffraction demonstrated that acid hydrolysis and CCE significantly impacted the crystallinity of the LCNCs; however, the bleaching effect was minimal. Thermal analysis revealed that LCNCs derived from post-treated pulps exhibited greater thermal stability than those from untreated pulps. LCNCs were utilized to create films using the solution-casting method. The produced films from various pulps and post-treatments displayed excellent and diverse mechanical and aesthetic properties. The results indicated that the pulping processes, post-treatments, and chemical composition of the pulps influenced the characteristics of both LCNCs and LCNC films. The findings suggest that CCE can be a cost-effective and eco-friendly alternative to bleaching in the production of LCNCs. Furthermore, an increase in lignin content within the pulps was found to reduce the efficiency of acid hydrolysis and crystallinity while increasing the dimensions of the LCNCs.