Maximizing the yield of water-soluble cellouronic acid sodium salt with high carboxyl content by 4-acetamide-TEMPO mediated oxidation of parenchyma cellulose from bagasse pith

Activation behavior of 4-AcNH-TEMPO by ClO2 for selective oxidation of cellulose in DMAc/LiCl system

“…The increase in carboxyl content induced stronger repulsive forces between the molecular chains, leading to the broadening of gaps between fibers. Therefore, the surface showed a rougher texture and fractured sections with a looser structure, which was consistent with the findings of previous studies (Zhang et al 2016b). demonstrated that while both samples exhibited high transparency, the ROC film (83.82%) showed a slightly lower level of transparency, as compared to the RC film (90.89%).…”

“…4(a) and (b). This comparison of mechanical properties also proved that the 4-AcNH-TEMPO/ClO2 catalytic system could effectively prevent the extensive destruction of cellulosic macromolecules during the oxidation reaction (Hirota et al 2012;Zhang et al 2016a;Isogai and Zhou 2019). Medical dressings made from traditionally oxidized cellulose-based materials, such as gauze and bandages, generally showed elongation in the range of approximately 15% to 25% (Jo et al 2021).…”

“…Furthermore, the reduction in crystallinity could also be primarily attributed to a decrease in DP of cellulose molecules. As the degree of polymerization decreased, it resulted in a less orderly arrangement of cellulose molecules during the regeneration process, consequently decreasing their crystallinity (Zhang et al 2016a).…”

“…O groups, respectively (Coseri and Biliuta 2012). The C 1s spectrum of RC was expected to show only two major peaks (peak 2 and peak 3), typical of the cellulose structure (Zhang et al 2016b). However, the extraction of cellulose from the raw materials by alkali treatment could have probably oxidized or chemically changed the structure of cellulose, that resulted in the spectrum showing two additional peaks (peak 1 and peak 4) (Gao et al 2014b).…”

“…The traditional oxidation system with catalytic amounts of 4-AcNH-TEMPO and NaClO using NaClO2 as the primary oxidant, converts the C6 primary hydroxyls (C6-OH) of cellulose to carboxyls in water or organic solvent-water mixture (Zhao et al 1999). First, NaClO oxidizes 4-AcNH-TEMPO to N-oxoammonium ion, which then rapidly oxidizes the C6-OH of cellulose to aldehyde and then to carboxyl by NaClO2 (Zhang et al 2016a). Due to its advantages of mild reaction conditions and high catalytic efficiency, the oxidation system of 4-AcNH-TEMPO has been extensively researched.…”