Reaction mechanism of Co-salen complex catalyzed oxidation of dimeric lignin model compound
1.Research Center of Pulp and Paper Engineering of Provincial Universities, Kunming University of Science and Technology, Kunming, Yunnan 650051, China; 2.State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, Zhejiang 310027, China)
Abstract:In order to investigate the Co-salen catalytic bleaching mechanism of pulp, the dimeric guaiacyl lignin model compound with β—O—4 linkage was synthesized. The degradation products and functional groups in Co-salen catalytic oxidation were analysed by GC-MS, FT-IR and 13C-NMR, respectively. The degradation mechanism of lignin model compound was elucidated based on the degradation products and structural changes. Attacks of peroxy anionic radical, hydroperoxy ion and hydroxy radical in Co-salen catalytic system made the β—O—4 linkage broke, ary ring open and methoxy reduced, yielding aldehyde, phenol and alkene.