Abstract
This work describes the production of nanocellulose by removing lignin from biomass by the peroxide method in the presence of an H2SO4 catalyst and the study of its physicochemical properties. The structure of cellulose and modified nanocellulose was studied using Raman spectroscopy, IR (infrared) spectroscopy, X-ray diffraction, and SEM (scanning electron microscopy). The resulting increase in the crystallinity of NFC (nanofibrous cellulose) was confirmed by X-ray diffraction analysis. This indicates that cellulose was associated with the removal of amorphous parts. As a result of X-ray diffraction, overlap on NFC radiographs occurred even in the area of intense lines. In the sample obtained by IR spectroscopy, the presence of groups (3413.12 cm−1; 2918.34 cm−1; 1373.30 cm−1; 617.52 cm−1) corresponding to the nature of NFC was detected. Strong absorption at 1429.8 cm−1 in the spectrum of CMC (carboxylmethylcellulose) revealed –COOH groups, indicating successful carboxylation of cellulose. The morphological surface, average particle size and structure of the samples were studied. As a result of a comparative analysis of morphological structures, an ordered filamentous structure of nanofibrous cellulose characteristic of fibers and a porous structure of CMC with a modified surface and uneven fibers were revealed. The developed method for producing modified cellulose from biomass does not require multi-stage processing compared to traditional methods and is safe for the environment. It has been shown that it is possible to obtain high-quality cellulose in one stage without the use of reagents containing sulfur and chlorine, high pressure and high water consumption.