Characterization of aspen exploded wood lignin

Marchessault, R. H.; Coulombe, S; Morikawa, Hiromichi; Robert, D.

doi:10.1139/v82-339

Cited by 114 publications

(47 citation statements)

References 17 publications

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“…The signals in the 1.9-2.2 pprn region have also been attributed to protons on saturated or reduced side chains (34). The high intensity of these signals in this case would indicate that fractions from PTOL contain more structures whose side chains are saturated than the corresponding fractions from TOL.…”

Section: Nuclear Magnetic Resonancementioning

confidence: 79%

Fractionation of woodmeal by prehydrolysis and thermal organosolv. Alkaline depolymerization, chemical functionality, and molecular weight distribution of recovered lignins and their fractions

Thring¹,

Chornet²,

Overend³

1993

Can. J. Chem.

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. Can. J . Chem. 71, 779 (1993). Thermal organosolv glycol lignins and their fractions have been characterized by means of elemental composition, molecular weight distribution, and 'H and I3c NMR spectroscopy. Fractionation of each lignin by sequential solvent extraction produced fractions of increasing molecular weight and polydispersity. Structures in the highest molecular weight fractions were found to be linked by a high proportion of P-0-4 type bonds, whilst the lowest molecular weight fractions consisted of a high content of saturated aliphatic side-chain structures. A noticeable difference in the content of carbohydrate contaminants in both starting lignins indicated the formation of relatively stable lignin-carbohydrate complexes, especially in the lignin recovered from pretreated wood. In addition, depolymerization of the lignins and their fractions to monomeric compounds was explored using alkaline hydrolytic and nitrobenzene oxidative routes. The highest molecular weight fractions from each lignin were identified as the best candidates for production of useful monomeric phenolic compounds. En se basant sur la composition ClCmentaire, la distribution des poids molCculaires et la RMN du 'H et du I3c, on a caractCrisC les lignines thermiques de l'organosolv glycol et leurs fractions. Le fractionnement de chaque lignine par extraction ~Cquentielle par les solvants a fourni des fractions de poids molCculaires et de polydispersitCs croissants. On a trouvC que les structures des fractions de poids molCculaires les plus ClevCs sont likes en grande partie par des liaisons de type P-0-4 alors que celles des fractions de poids molCculaires plus faibles comportent de grandes quantites de chaines laterales aliphatiques saturkes. On a not6 une difference notablehans le contenuen hydrates de carbone des deux lignines; elle indique qu'il y a formation de complexes lignine -hydrate de carbone relativement stables, particulikrement dans la lignine rCcupCrCe du bois prCtraitC. On a de plus examine la dCpolymCrisation des lignines et de leurs fractions en composCs monomeres par hydrolyse alcaline et par oxydation avec du nitrobenzkne. Pour la production de composCs phCnoliques monomkres utiles, on a identifiC que les fractions de poids molCculaires les plus ClevCs de chacune des lignines seraient les plus appropriCes.[Traduit par la rCdaction]

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Section: Nuclear Magnetic Resonancementioning

confidence: 79%

Fractionation of woodmeal by prehydrolysis and thermal organosolv. Alkaline depolymerization, chemical functionality, and molecular weight distribution of recovered lignins and their fractions

Thring¹,

Chornet²,

Overend³

1993

Can. J. Chem.

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“…The equivalent circuit was proposed, and the values of the circuit elements were obtained using the software available with a CH instrument. From Rct value or polarization resistance, the inhibition efficiencies were calculated by the following equation [16]: (4) where and represent the charge transfer resistance, respectively in the absence and presence of the inhibitor.…”

Section: Electrochemical Impedance Spectroscopymentioning

confidence: 99%

Corrosion Inhibition Performance of Lignin Extracted from Black Liquor on Mild Steel in 0.5 M H2SO4 Acidic Media

Shivakumar

Dharmaprakash

Manjappa

et al. 2017

Port. Electrochim. Acta

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In this study, lignin, a polyhydroxy compound, was extracted from black liquor of pulp and paper industry, and characterized. In view of the potential of such polyhydroxy compounds to adsorb onto metal surfaces, the corrosion inhibition efficiency of lignin on the corrosion of mild steel by 0.5 M H2SO4 has been studied using weight loss method, electrochemical polarization and impedance methods. The morphological changes of the surface during corrosion, in the presence and absence of the inhibitor, were studied by scanning electron microscopy. Results of these studies show that lignin does inhibit the corrosion of mild steel by sulfuric acid, and that the inhibition efficiency increased with lignin's concentration.

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“…The peaks at 2.0, 2.1, and 2.2 ppm arose from the methyl protons adjacent to double bonds or carbonyl groups. 44 The small signals at 8.7, 9.1, and 9.3 ppm are attributed to the C¼ ¼O groups in aldehydes such as cinnamaldehyde and benzaldehyde structures. These results indicate that b-aryl ether bond (b-O-4) and b-b carbon-carbon linkages are the abundant interunit linkages in the lignin structure.…”

mentioning

confidence: 99%

Comparative study of three lignin fractions isolated from mild ball‐milled Tamarix austromogoliac and Caragana sepium

Sun

Zhai³

et al. 2008

J of Applied Polymer Sci

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Six lignin fractions from mild ball-milled Tamarix austromogoliac (TA) and Caragana sepium (CS) were sequentially isolated with 80% dioxane containing 0.05M HCl at 758C for 4 h, 50% aqueous ethanol containing 1M triethylamine at 708C for 4 h, and 8% aqueous NaOH at 458C for 3 h. The results showed that the successive treatments made it possible to isolate lignin from wood with a high yield and purity, in which 89.4 and 90.6% of the original lignin from TA and CS were released, respectively. The lignin fractions isolated with the three-step method were analyzed with Fourier transform infrared, 1 H-and 13 C-NMR, alkaline nitrobenzene oxidation, and gel permeation chromatography. It was found that the three lignin fractions isolated from TA were rich in syringyl units, and the molar ratio of the relatively total moles of vanillin, vanillic acid, and acetovanillin to the relatively total moles of syringaldehyde, syringic acid, and acetosyringone decreased from 1 : 2.6 to 1 : 3.2 to 1 : 3.6 in the lignin preparations, whereas this ratio in the corresponding lignin fractions isolated from CS was found to be 1.4 : 1, 1.1 : 1, and 1 : 1.4, respectively. More importantly, the results revealed that the sequential extractions of the mild ball-milled TA and CS with 80% acidic dioxane, 50% alkaline ethanol, and 8% aqueous NaOH under the conditions used did not significantly cleave the b-O-4 and a-O-4 linkages in lignin macromolecules.

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Characterization of aspen exploded wood lignin

Cited by 114 publications

References 17 publications

Fractionation of woodmeal by prehydrolysis and thermal organosolv. Alkaline depolymerization, chemical functionality, and molecular weight distribution of recovered lignins and their fractions

Fractionation of woodmeal by prehydrolysis and thermal organosolv. Alkaline depolymerization, chemical functionality, and molecular weight distribution of recovered lignins and their fractions

Corrosion Inhibition Performance of Lignin Extracted from Black Liquor on Mild Steel in 0.5 M H2SO4 Acidic Media

Comparative study of three lignin fractions isolated from mild ball‐milled Tamarix austromogoliac and Caragana sepium

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