title: Isolation and characterization of lignin from the oak wood bioethanol production residue for adhesives.
abstract: Lignin was isolated from the residue of bioethanol production with oak wood via alkaline and catalyzed organosolv treatments at ambient temperature to improve the purity of lignin for the materials application. The isolated lignins were analyzed for their chemical composition by nitrobenzene oxidation method and their functionality was characterized via wet chemistry method, element analysis, (1)H NMR, GPC and FTIR-ATR. The isolated lignin by acid catalyzed organosolv treatment (Acid-OSL) contained a higher lignin content, aromatic proton, phenolic hydroxyl group and a lower nitrogen content that is more reactive towards chemical modification. The lignin-based adhesives were prepared and the bond strength was measured to evaluate the enhanced reactivity of lignin by the isolation. Two steps of phenolation and methylolation were applied for the modification of the isolated lignins and their tensile strengths were evaluated for the use as an adhesive. The acid catalyzed organosolv lignin-based adhesives had comparable bond strength to phenol-formaldehyde adhesives. The analysis of lignin-based adhesives by FTIR-ATR and TGA showed structural similarity to phenol adhesive. The results demonstrate that the reactivity of lignin was enhanced by isolation from hardwood bioethanol production residues at ambient temperature and it could be used in a value-added application to produce lignin-based adhesives.
authors.affiliation: Bio-energy Research Center, Chonnam National University, Gwangju 500-757, Republic of Korea.
authors.forename: Soo Jung
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: Department of Forest Products and Technology, Chonnam National University, Gwangju 500-757, Republic of Korea.
authors.forename: Hyun Joo
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Bio-energy Research Center, Chonnam National University, Gwangju 500-757, Republic of Korea.
authors.forename: Eun Jin
authors.initials: EJ
authors.lastname: Cho
authors.affiliation: Department of Bioenergy Science and Technology, Chonnam National University, Gwangju 500-757, Republic of Korea.
authors.forename: Younho
authors.initials: Y
authors.lastname: Song
authors.affiliation: Bio-energy Research Center, Chonnam National University, Gwangju 500-757, Republic of Korea; Department of Forest Products and Technology, Chonnam National University, Gwangju 500-757, Republic of Korea; Department of Bioenergy Science and Technology, Chonnam National University, Gwangju 500-757, Republic of Korea. Electronic address: baehj@chonnam.ac.kr.
authors.forename: Hyeun-Jong
authors.initials: HJ
authors.lastname: Bae
mesh_terms: D000269:Adhesives / Q000737:chemistry; D000431:Ethanol / Q000737:chemistry; D005557:Formaldehyde / Q000737:chemistry; D008031:Lignin / Q000737:chemistry* / Q000302:isolation & purification; D009682:Magnetic Resonance Spectroscopy; D009578:Nitrobenzenes / Q000737:chemistry; D010636:Phenols / Q000737:chemistry; D029963:Quercus / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014934:Wood / Q000737:chemistry
chemical_list: D000269:Adhesives; D009578:Nitrobenzenes; D010636:Phenols; D012997:Solvents; D005557:Formaldehyde; D000431:Ethanol; D008031:Lignin; C036077:nitrobenzene
keywords: Bioethanol production residue; Lignin; Reactivity