Cristalinidad de microfibras de celulosa obtenidas de Cistus ladanifer y Erica arborea

Abstract

The effectiveness of the use of cellulose fibers as particulates/composite reinforcers involves the assessment of the crystallinity of such fibers. The aim of the present work is to provide information on the degree of crystallinity of the cellulose microfibers obtained from the stems of Cistus ladanifer and Erica arborea shrubs through two different methods, namely an alkaline treatment and a microwave-assisted deep eutectic solvent (DES) method. The crystallinity indexes (CrI) obtained from X-ray powder diffraction patterns indicated that higher CrI were attained for cellulose obtained from the DES treatment. Complementary information on the degree of crystallinity was also retrieved from attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) vibrational spectra, scanning electron microscopy (SEM) micrographs, and accessibility data for the DES-treated celluloses from the two species. The crystallinity results for the fibers derived from these two Mediterranean shrubs were within the range of the results for those derived from wood pulp, opening the door to their valorization for cellulose-derived packing applications or for their use as reinforcers in composite materials in combination with other biopolymers.

Production of Cellulosic Microfibers from Coffee Pulp via Alkaline Treatment, Bleaching and Acid Hydrolysis

“…As seen in the micrograph, with T5, lignin and hemicellulose percentage reduction was achieved, but the formation of the CMFs was not complete. Similar micrographs were obtained for biomass lignin by C. Landanifertallo [54]. Figure 8b corresponds to coffee pulp after T6 (NaOH at 20%, 120 • C and 3 h).…”

“…Dai et al analyzed pineapple crowns at a NaOH concentration of 10% and obtained a CI difference of 11% with respect to their original sample [53]. Conversely, Carrión Prieto et al worked with a NaOH concentration of 25% at room temperature and obtained a CI increase of 12% in comparison with their sample without treatment [54]. Based on the previous points, it is possible to conclude that the factors established in the experimental design improved the cellulose yield.…”

Comparison of Treatments by Mercerization and Plasma Glow Discharge on Residues of the Amazon Chestnut Shell (Bertholletia Excelsa)

“…Considering that the changes in cellulose crystallinity are attributed to the degradation of lignocellulose and hemicellulose, a method has been proposed to quantitatively determine these changes based on the ratio of the intensities of the bands at 380 and 1 096 cm −1 (I 380 /I 1096 ) and a data treatment with univariate analysis to solve problems involving the presence of fluorescence in the spectra (Agarwal et al, 2010;Agarwal et al, 2013). Similar works to determine the crystallinity of cellulose fibers have used X-ray diffraction patterns, with discrepancies in the reliability of the results obtained when varying the size of the fibers (Carrión-Prieto et al, 2019). Contrary to the spectra obtained in this study, due to the interaction of the signal that relates hemicellulose and pectin, a Raman dispersion can be produced, leading to an imprecise measurement of cellulose crystallinity (Anderson et al, 2003).…”

Rockrose Land Management: Contribution of Periodic Harvesting to Increase Value and to Control Cistus ladanifer L. Shrublands

“…In fact, C. ladanifer biomass, mainly the wood fraction, may be considered for pellets [18], biochar and biogas [19], and bioethanol [20] production. Biomass may also be transformed into lignin-derivatives and glucan rich solids to be used in bioconversion processes [21], such as lactic-acid production [22] and valorised as a source of cellulose with wood pulp such as crystallinity [23]. Leaves and soft stems as well as condensed tannin extracts have been pointed out for ruminant feeding to some extent [24][25][26].…”