Microfibrillated Cellulose with a Lower Degree of Polymerization; Synthesis via Sulfuric Acid Hydrolysis under Ultrasonic Treatment

Abstract

A new approach is being considered for obtaining microfibrillated cellulose with a low degree of polymerization by sulfuric acid hydrolysis with simultaneous ultrasonic treatment under mild conditions (temperature 25 °C, 80% power control). Samples of initial cellulose, MCC, and MFC were characterized by FTIR, XRF, SEM, DLS, and TGA. It was found that a high yield of MFC (86.4 wt.%) and a low SP (94) are observed during hydrolysis with ultrasonic treatment for 90 min. It was shown that the resulting microfibrillated cellulose retains the structure of cellulose I and has an IC of 0.74. It was found that MFC particles are a network of fibrils with an average size of 91.2 nm. ζ-potential of an aqueous suspension of MFC equal to −23.3 mV indicates its high stability. It is noted that MFC has high thermal stability, the maximum decomposition temperature is 333.9 °C. Simultaneous hydrolysis process with ultrasonic treatment to isolate MFC from cellulose obtained by oxidative delignification of spruce wood allows to reduce the number of stages, reduce energy costs, and expand the scope.

Exploring the partial degradation of polysaccharides: Structure, mechanism, bioactivities, and perspectives

“…TFA is a relatively mild acid and causes the minimal degradation of polysaccharides. Under high‐temperature conditions, HCl with strongly electronegative atom can cleavage glycosidic linkages that are difficult to hydrolyze; however, H 2 SO 4 can hydrolyze powerful β‐(1 → 4)‐linkages of cellulose (Malyar et al., 2023). In the process of partial acid hydrolysis, factors, such as reaction temperature, time, and reagent concentration, significantly affect the formation of polysaccharide fragments.…”

Nanotechnology Applied to Cellulosic Materials

“…This process yielded 41.2% microcrystalline cellulose that, after sulfuric acid hydrolysis and ultrasonic treatment, produced microfibrillated cellulose with a yield of 31.8% and nanocrystalline celluloses with a yield of 10.9%. A similar approach was used to obtain microfibrillated cellulose with a low degree of polymerization from spruce wood pulp, which made it possible to decrease the number of stages, decrease energy costs, and increase the range of applications, according to the authors [60].…”