Radicalization of lignocellulosic fibers, related structural and morphological changes

C Canevali, M Orlandi, L Zoia, R Scotti, E L Tolppa, J Sipila, F Agnoli, F Morazzoni

    Research output: Contribution to journalArticleScientificpeer-review

    Abstract

    "The radicalization of unbleached lignocellulosic fibers obtained from thermomechanical (TMP) and chemothermomechanical (CTMP) pulps was performed in heterogeneous phase by reaction with dioxygen in the presence of N,N′-ethylenebis(salicylideneiminato)cobalt(II), [Co(salen)], as catalyst. Phenoxy cobalt radicals immobilized in fibers were observed by electron paramagnetic resonance (EPR) spectroscopy; their amount depends on the fiber swelling induced by reaction medium. The absolute concentration of such radicals in fibers, about 10(16) spin/g, reaches values 10 times higher than that of phenoxy radicals formed in similar oxidative reactions catalyzed by laccase. The generation of phenoxy cobalt radicals in fibers was related to structural changes of lignin units, detected by mono- and bidimensional nuclear magnetic resonance (C-13 NMR and 2D-HSQC) investigations, and to morphological modifications in fibers observed by scanning electron microscopy (SEM)."
    Original languageEnglish
    JournalBiomacromolecules
    Volume6
    Issue number3
    Pages (from-to)1592-1601
    Number of pages10
    ISSN1525-7797
    DOIs
    Publication statusPublished - 2005
    MoE publication typeA1 Journal article-refereed

    Fields of Science

    • COMPLEX-CATALYZED OXIDATION
    • MILLED WOOD LIGNIN
    • PARASUBSTITUTED PHENOLICS
    • NMR-SPECTROSCOPY
    • HYDROXYL-GROUPS
    • KRAFT PULP
    • LACCASE
    • IDENTIFICATION
    • REACTIVITY
    • 116 Chemical sciences

    Cite this

    Canevali, C., Orlandi, M., Zoia, L., Scotti, R., Tolppa, E. L., Sipila, J., ... Morazzoni, F. (2005). Radicalization of lignocellulosic fibers, related structural and morphological changes. Biomacromolecules, 6(3), 1592-1601. https://doi.org/10.1021/bm050012i