Photodegradation of Acidolysis Lignin from BCMP

Mohammad Azadfallah, Seyed Mirshokraei, Ahmad Latibari
2008 Molecules  
A mild acidic dioxane extraction method was employed to isolate lignin from hardwood bleached chemimechanical pulp (BCMP). The isolated lignin was then purified and undergone elemental analysis. To study the photodegradation behavior, the lignin samples were impregnated onto the Whatman filter papers and irradiated with UV light for various periods. The photolyzed lignin was then recovered and analyzed by 1 H-NMR spectroscopy. Phenylpropane-based formula (C 9 ) of CMP pulp lignin and the
more » ... zed samples were then established with elemental analysis and 1 H-NMR spectroscopy data. The results indicated that the benzaldehyde and benzoic acid type compounds were the main photodegradation products of BCMP lignin. The lignin photodegradation probably involved the degradation of phenylcoumaran units. Irradiation also increased the phenolic hydroxyl group content and decreased that of methoxyl groups, due to demethoxylation. The degrees of aromatic ring condensation were increased upon continuing the irradiation time, which imples the formation of condensed structures in photolyzed lignin.
doi:10.3390/molecules13123129 pmid:19078854 fatcat:crdu26g6pzg3bay7vhfu76mpvq