Simultaneous Production of Cellulose Nitrates and Bacterial Cellulose from Lignocellulose of Energy Crop

Abstract

This study is focused on exploring the feasibility of simultaneously producing the two products, cellulose nitrates (CNs) and bacterial cellulose (BC), from Miscanthus × giganteus. The starting cellulose for them was isolated by successive treatments of the feedstock with HNO3 and NaOH solutions. The cellulose was subjected to enzymatic hydrolysis for 2, 8, and 24 h. The cellulose samples after the hydrolysis were distinct in structure from the starting sample (degree of polymerization (DP) 1770, degree of crystallinity (DC) 64%) and between each other (DP 1510–1760, DC 72–75%). The nitration showed that these samples and the starting cellulose could successfully be nitrated to furnish acetone-soluble CNs. Extending the hydrolysis time from 2 h to 24 h led to an enhanced yield of CNs from 116 to 131%, with the nitrogen content and the viscosity of the CN samples increasing from 11.35 to 11.83% and from 94 to 119 mPa·s, respectively. The SEM analysis demonstrated that CNs retained the fiber shape. The IR spectroscopy confirmed that the synthesized material was specifically CNs, as evidenced by the characteristic frequencies of 1657–1659, 1277, 832–833, 747, and 688–690 cm−1. Nutrient media derived from the hydrolyzates obtained in 8 h and 24 h were of good quality for the synthesis of BC, with yields of 11.1% and 9.6%, respectively. The BC samples had a reticulate structure made of interlaced microfibrils with 65 and 81 nm widths and DPs of 2100 and 2300, respectively. It is for the first time that such an approach for the simultaneous production of CNs and BC has been employed.

Cellulose Nitrates-Blended Composites from Bacterial and Plant-Based Celluloses

“…As the degree of substitution increased, the nitrogen content of the CN samples (Table 2) also increased, while the intensity of hydroxyl peaks became less pronounced. This observation aligns with previous studies reported in [8,11,37,57,58]. Specifically, the CN NA + MC samples exhibited a lower hydroxyl intensity compared to the CN MA samples, consistent with their higher nitrogen content.…”

“…OHC was inferior to BC in quality attributes but was characterized by quite high quality values for plant-based cellulose, namely, 93.8% α-cellulose content, 0.8% lignin, 0.8% pentosans, 0.31% ash, and 1450 DP. These high values of quality for OHC are comparable to those of Miscanthus cellulose [11] and higher than those of celluloses from oil palm empty fruit bunch, kenaf fibers [12], coffee pulp [18], giant panda feces, and bitter bamboo stems [19], which were successfully nitrated. The blended cellulose samples had intermediate DP values, comparable to the proportional ratio of BC to OHC.…”

“…Despite CN MA exhibiting a lower viscosity compared with CN NA + MC, the CN BC MA samples were, however, characterized by a rather high viscosity of 1050 mPa•s in general, which is significantly higher than that of classical CNs [46]. The CN OHC MA sample exhibited a lower viscosity typical of CNs from plant-based cellulose [8,11,15,46]. The CNs-blended composites exhibited an intermediate viscosity between CN BC MA and CN OHC MA (200-610 mPa•s) in accordance with the proportional content of CN BC/CN OHC.…”

“…Cotton and wood are considered to be classical raw materials for the synthesis of CNs. Active works are currently underway on the synthesis of CNs from alternative cellulosic feedstocks such as Alfa grass fibers [8], intermediate flax [9], Miscanthus [10,11], oil palm empty fruit bunch, kenaf fibers [12], Posidonia oceanica [13], Acacia mangium [14],…”

Water-Based Generators with Cellulose Acetate: Uncovering the Mechanisms of Power Generation

“…The representative chemical structure of the CAC comprises O-H (3499 cm −1 ), C-H (2923 cm −1 ), C=O (1759 cm −1 ), and CH 3 (1390 cm −1 ). CB is a suitable conductive material owing to its O-H (3499 cm −1 ) groups, high conductivity, and specific surface area [40][41][42]. In the CACG FT-IR results, the transmittance of C-H and C=O decreased, and the presence of O-H and COO-showed that the CAC was well coated with carbon black.…”