Analysis of oxidized cellulose introduced into ramie fiber by oxidation degumming

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.