title: Effect of hydrothermal pretreatment on the structural changes of alkaline ethanol lignin from wheat straw.
abstract: Due to the enormous abundance of lignin and its unique aromatic nature, lignin has great potential for the production of industrially useful fuels, chemicals, and materials. However, the rigid and compact structure of the plant cell walls significantly blocks the separation of lignin. In this study, wheat straw was hydrothermally pretreated at different temperatures (120-200 °C) followed by post-treatment with 70% ethanol containing 1% NaOH to improve the isolation of lignin. Results demonstrated that the content of associated carbohydrates of the lignin fractions was gradually reduced with the increment of the hydrothermal severity. The structure of the lignins changed regularly with the increase of the pretreatment temperature from 120 to 200 °C. In particular, the contents of β-O-4', β-β', β-5' linkages and aliphatic OH in the lignins showed a tendency of decrease, while the content of phenolic OH and thermal stability of the lignin fractions increased steadily as the increment of the pretreatment temperature.
authors.affiliation: Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China.
authors.forename: Xue
authors.initials: X
authors.lastname: Chen
authors.affiliation: Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China.
authors.forename: Hanyin
authors.initials: H
authors.lastname: Li
authors.affiliation: Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China.
authors.forename: Shaoni
authors.initials: S
authors.lastname: Sun
authors.affiliation: Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China.
authors.forename: Xuefei
authors.initials: X
authors.lastname: Cao
authors.affiliation: Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China.
authors.forename: Runcang
authors.initials: R
authors.lastname: Sun
mesh_terms: D000468:Alkalies; D000431:Ethanol; D008031:Lignin / Q000302:isolation & purification*; D018547:Plant Stems / Q000737:chemistry* / Q000528:radiation effects*; D012997:Solvents; D013696:Temperature; D014908:Triticum / Q000737:chemistry* / Q000528:radiation effects*
chemical_list: D000468:Alkalies; D012997:Solvents; D000431:Ethanol; D008031:Lignin