caa a22 4500 463247124 CHVBK 20180405153329.0 cr unu---uuuuu 170326e20070201xx s 000 0 eng 10.1007/s10086-006-0822-3 doi (NATIONALLICENCE)springer-10.1007/s10086-006-0822-3 Spectral analysis of the successive degradation process of kraft lignin by alkaline oxygen treatment [Elektronische Daten] [Minoru Yada, Gyosuke Meshitsuka] Softwood kraft lignin was subjected to alkaline oxygen treatment in a fundamental study of lignin degradation. Two different spectral changes were observed in the time course of ultraviolet-visible spectra along with the progress of the treatment. These spectral changes could be recognized as proceeding along certain temporal functions that were based on second-order decays with different halflives. The spectral changes were defined as "fast change” and "slow change.” The fitting studies on the amount of total protons on the unsaturated and aromatic systems, the amount of unconjugated phenolic substructure determined by differential ionization spectra, and the amount of methoxyl group with temporal functions showed that two reaction types (formation of muconate derivatives and ortho-quinone derivatives) can be expected as the major modification types occurring during fast change. The fitting study of the time course of infrared attenuated total reflectance (ATR) spectra gave corresponding infrared ATR spectral features of fast and slow changes. The occurrence of the formation of muconate derivatives by fast change was strongly supported by the spectral feature of fast change. On the other hand, it is suggested that the aromatic structure of lignin was further degraded during slow change. In addition, formation of resistant phenolic substructures is suggested as another possible modification type occurring by fast change. The Japan Wood Research Society, 2006 Kraft lignin nationallicence Oxygen delignification nationallicence Numerical analysis nationallicence Spectroscopy nationallicence Yada Minoru Laboratory of Wood Chemistry, Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, 113-8657, Bunkyo-ku, Tokyo, Japan aut Meshitsuka Gyosuke Laboratory of Wood Chemistry, Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, 113-8657, Bunkyo-ku, Tokyo, Japan aut Journal of Wood Science Springer-Verlag 53/1(2007-02-01), 47-53 1435-0211 53:1<47 2007 53 10086 https://doi.org/10.1007/s10086-006-0822-3 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10086-006-0822-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Yada Minoru Laboratory of Wood Chemistry, Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, 113-8657, Bunkyo-ku, Tokyo, Japan aut NATIONALLICENCE 700 1- Meshitsuka Gyosuke Laboratory of Wood Chemistry, Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, 113-8657, Bunkyo-ku, Tokyo, Japan aut NATIONALLICENCE 773 0- Journal of Wood Science Springer-Verlag 53/1(2007-02-01), 47-53 1435-0211 53:1<47 2007 53 10086 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer