Abstract
Using time-resolved CIDEP and conventional ESR as well as optical studies much can be elucidated concerning the initial photochemical reactions of lignin model compounds such as α-guaiacoxyacetoveratrone and α-guaiacoxy-β-propioveratrone. The resulting transient radicals are models for intermediates in the processes of photoyellowing of lignin containing mechanical pulps and papers. Model solution experiments which produce evidence for the roles of free radicals in reductive bleaching of mechanical pulps and in the oxidative aging of papers are also described. The more thorough understanding of these complex processes allows the development of strategies to try to “protect” mechanical pulps and papers from light and thermally induced damage and to “repair” any damage which invevitably occurs.
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Wan, J.K.S., Depew, M.C. Applications of ESR and CIDEP to mechanistic studies of lignin chemistry. Res. Chem. Intermed. 24, 831–847 (1998). https://doi.org/10.1163/156856798X00320
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DOI: https://doi.org/10.1163/156856798X00320