Potential application of cellulose nanocrystals obtained from cultivated fibers in Amazon forest

Abstract

The Amazon fibers, Jute (Corchorus capsularis L.) and Malva/Caesarweed (Urena lobata L.), obtained from Phoenix Amazon Project were scrutinized and the biomass components were quantified according to the TAPPI standards. The cellulose amount from jute and caesarweed was, respectively, around 49% and 41%. Scanning Electron Microscopy (SEM) analysis has evaluated the removal of lignin of the fiber through the micro holes located at holocellulose’s samples and the hemicellulose partial removal through the samples’ fibrillation at alphacellulose’s micrographs. The Fourier Transform Infrared spectroscopy (FTIR) results corroborated the delignification and hemicellulose removal through the alphacellulose obtention process. X-Ray Diffraction (XRD) patterns reiterate type I cellulose for the raw/holo samples, and type II cellulose for the bleached ones, with an increase of the crystallinity index from ~60% to ~85% for the samples. Thermogravimetry (TG) showed that the thermal stability of the samples increased until the bleaching process, and decreased after the cellulose nanocrystals (CNCs) extraction because of the ester sulphate groups insertion. The CNCs were successfully extracted, as can be seen on the Atomic Force Microscopy (AFM) images, and the aspect ratio and specific surface area calculated showed that these CNCs present some potential application in polymers matrices.