Extraction and characterization of nanofibrillated cellulose from yacon plant (Smallanthus sonchifolius) stems

This study aimed to evaluate the process of cellulose extraction from yacon stem using combined pulping and bleaching processes to produce nanofibrillated cellulose (NFC). First, a chemical pulping process with NaOH was applied and, subsequently, the pulp obtained was bleached. From the chemical pulp (CP) bleached, NFC was obtained by the mechanical defibrillation in a colloidal grinder. Then, chemical composition, and infrared analysis of the pulps were performed. The pulping process showed a lower amount of extractives and lignin content, as a low yield and an excessively dark pulp. The CP bleached with NaClO₂ showed the best results increased whiteness of the pulp. A suspension of NFC with fibers of 5-60 nm in diameter, high crystallinity index, and thermal stability was obtained. The results are promising and demonstrate the technical feasibility of obtaining NFC from yacon stems waste which is ideal to apply to other materials of the industry.(author)