Analysis of oxidized cellulose introduced into ramie fiber by oxidation degumming

Abstract

Oxidized cellulose can be produced from the oxidation reaction of hydrogen peroxide in the degumming process of ramie fibers. In this work, the contents of aldehyde and carboxylate groups in ramie cellulose which occurred during the degumming process were quantitatively determined by the electric conductivity titration method. The morphological changes and chemical components of oxidized cellulose were characterized using SEM, XRD, and FT-IR. Additionally, the relationship between the contents of the oxidized groups and the mechanical properties of the degummed fibers were discussed and analyzed. Results showed that the presence of aldehyde and carboxylate groups in the cellulose contributed significantly to the loss of tenacity, breaking elongation, softness, and degree of polymerization of degummed fibers. When the aldehyde content varied from 20 to 35 µmol/g and the carboxylate content varied from 140 to 180 µmol/g, respectively, raw fibers could achieve desired and reasonable degumming results. This study could offer useful information in obtaining optimal operation parameters for ramie oxidation degumming and better control of fiber quality. The degree of oxidation and content of oxidized cellulose could be used as effective indicating factors to demonstrate oxidation degumming efficiency and fiber properties.

Effect of Growth Period and Sampling Section on the Chemical Composition and Microstructure of Raw Hemp Fibers

“…The crystallinity of L-T fibers, which had inferior peak intensity, was undoubtedly the smallest. This was because the crystallinity is greatly influenced by the cellulose content (Li et al 2015;Meng et al 2016). With a higher cellulose content, the content of non-cellulosic materials, which contained lots of amorphous materials and impurities, is lower (Ebringerová et al 2005), resulting in a larger crystallinity index.…”

Extraction of Ramie Fiber in Alkali Hydrogen Peroxide System Supported by Controlled-release Alkali Source

“…NOTE: ORP 12,19 is an important water chemistry parameter and it provides a measurement tool for the oxidizing or reducing capacity of the ambient water. Solutions with stronger oxidation property have a higher ORP value.…”

“…Nevertheless, the harsh reaction condition and sophisticated equipment inhibit its further industrial application 9,10 . Therefore, oxidation degumming with alkali hydrogen peroxide presents a valuable and alternative application to focus on, for it requires shorter degumming time and lower degumming temperature 11,12 . However, due to the strong oxidation ability of the peroxides, substantial cellulose degradation may occur during the degumming process, which can cause great damage to fiber properties 13,14 .…”

The Use of Reductants in Oxidation Degumming of Ramie

“…However, most of these methods focused on preventing cellulose from degradation, the study on acid groups were seldom studied. Li 14 tried to convert the acid groups in oxidation degummed ramie fiber back to hydroxyl groups by reducing the fiber in NaH 4 B solution, and results showed that this process was very helpful in improving the tensile properties of fiber, However, this important process has not been studied sufficiently yet.…”