title: Isolation of lignin by organosolv process from different varieties of rice husk: Understanding their physical and chemical properties.
abstract: The aim of this work was to study the difference in properties of lignins, those (organosolv lignins (ORGLs, 12±3% yield and 93±5% mass balance) were isolated from diverse rice husk (RH) substrates using organosolv procedure (water:ethanol, H2SO4) carried out at 180°C for 1h. To identify the possible alterations in lignin structures several bulk and molecular level advanced characterization tools were employed. Even though lignins were extracted using common isolation procedure from three varieties of similar species of RH; from XRD, GPC, and elemental analysis it was found that those have comparable properties on bulk level. But molecular level analysis conducted using UV-vis, ATR, 1D/2D HSQC NMR techniques could help disclose that isolated lignins have varying concentrations of G, H, S and T substructures. Additionally, the double bond equivalence of 4.4-4.7 reveals that few of the aromatic rings are devoid of substituent.
authors.affiliation: Catalysis & Inorganic Chemistry Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411 008, India; Academy of Scientific and Innovative Research (AcSIR), New Delhi 110 025, India.
authors.forename: Sandip K
authors.initials: SK
authors.lastname: Singh
authors.affiliation: Catalysis & Inorganic Chemistry Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411 008, India; Academy of Scientific and Innovative Research (AcSIR), New Delhi 110 025, India. Electronic address: pl.dhepe@ncl.res.in.
authors.forename: Paresh L
authors.initials: PL
authors.lastname: Dhepe
mesh_terms: D018533:Biomass; D002625:Chemistry, Organic / Q000379:methods*; D000431:Ethanol / Q000737:chemistry; D008031:Lignin / Q000737:chemistry / Q000302:isolation & purification*; D009682:Magnetic Resonance Spectroscopy; D008970:Molecular Weight; D055601:Organic Chemistry Phenomena; D012275:Oryza / Q000737:chemistry*
chemical_list: D000431:Ethanol; D008031:Lignin
keywords: Lignin; Lignocelluloses; NMR; Organosolv isolation; Physico-chemical properties