E.I. Evstigneyev, O.S. Yuzikhin, A.A. Gurinov, A.Yu. Ivanov, T.O. Artamonova, M.A. Khodorkovskiy, E.A. Bessonova, A.V. Vasilyev
“Study of Structure of Industrial Acid Hydrolysis Lignin, Oxidized in the H2O2-H2SO4 System”
J. Wood Chem. Technol., 2016, 36, 259-269
DOI:10.1080/02773813.2015.1137945
Products of oxidation of industrial acid hydrolysis lignin in the H2O2-H2SO4 system were studied using 13C NMR (in solution and solid state), MALDI-MS, and MS(ESI) techniques. Oxidation of hydrolysis lignin leads to the opening of aromatic rings of lignin, yielding carboxylic groups. Alkyl aryl ether linkages (β-O-4-bonds) between lignin phenyl propane units are not significantly affected by the oxidation. The structure of oxidized hydrolysis lignin is proposed. The basic structural unit of oxidized hydrolysis lignin is a muconic acid derivative.