Oxidative Degradation of Lignin-Containing Flax Impurities

Complex studies of Klason lignin (acid-insoluble residue) were carried out to examine the formation of its water-soluble products. An IR-spectroscopic analysis was employed to investigate the state of Klason lignin modified by treatment with alkaline and peroxide solutions and by subsequent oxidative cooking. Analysis of the spectrophotometric data revealed their maximal changes relative to the initial data after activation of lignin with hydrogen peroxide in alkaline and acidic media. Less profound changes in the state of lignin in the alkaline medium were due to condensation of the resulting low-molecular-weight products.