Carbonyl Groups in Lignin. IV. Infrared Absorption Studies and Examination of the Volumetric Borohydride Method.

Marton, Josef; Adler, Erich; Persson, Karl-Ingvar; Dam, H. van; Sjöberg, Berndt; Toft, Jens

doi:10.3891/acta.chem.scand.15-0384

Cited by 33 publications

(9 citation statements)

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“…The content of cinnamaldehyde units in spruce-milled wood lignin is around 4 per 100 C 9 -units (one phenolic and three etherified). Approximately the same amount is found in unbleached softwood groundwood pulp (Adler and Marton 1959;Marton et al 1961;Hirashima and Sumimoto 1987;Brunow and Lundquist 2010). Cinnamaldehydes are efficiently sulfonated by sodium sulphite (CTMP-production) and are degraded during alkaline hydrogen peroxide-bleaching although, in industrial practice, probably not completely Hirashima and Sumimoto 1987;Suckling 1991;Gellerstedt and Zhang 1992;Lundquist et al 2007).…”

Section: Other Reactionsmentioning

confidence: 93%

Review: Light-Induced Yellowing of Lignocellulosic Pulps – Mechanisms and Preventive Methods

Paulsson¹,

Parkås²

2012

BioResources

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This review will focus on recent progress regarding the mechanisms of light-induced discoloration of mechanical and chemimechanical pulps and on the proposed preventive treatments. It is evident that the mechanisms behind photoyellowing of lignin-rich pulps are complex and that several types of reaction pathways may coexist. Photoyellowing proceeds via one initial fast phase and a slower following phase. The fast phase has been ascribed to oxidation of free phenolic groups and/or hydroquinones and catechols to photoproducts of mainly quinonoid character. A multitude of reactions involving several lignin subunits are possible. Important intermediates are phenoxyl radicals, and to some extent ketyl radicals. The importance of the phenacyl aryl ether pathway might be more important than previously thought, even though the original content of such groups is low in lignin. Even though many preventive methods against photoyellowing have been suggested, no cost-efficient treatment is available to hinder photoreversion of lignincontaining paper permanently. Suggested methods for stabilization include chemical modification (etherification and esterification), coating the paper product, addition of radical scavengers, excited state quenchers, or ultraviolet absorbing compounds.

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Section: Other Reactionsmentioning

confidence: 93%

Review: Light-Induced Yellowing of Lignocellulosic Pulps – Mechanisms and Preventive Methods

Paulsson¹,

Parkås²

2012

BioResources

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“…This indicates the presence of unconjugated ketone and/or aldehyde groups as well as carboxyl ester groups in aspen EXWL. In the spectra of lignin preparations including MWL and solvolysis lignins, the bands observed at 1710-1750 cm-' are attributed to unconjugated carboxyl ester groups (6,13) or unconjugated aliphaticor P-ketone groups (12,(14)(15)(16)(17)(18). It should be noted that in the reported lignin spectra the bands due to conjugated carbonyl groups are observed at 1660-1670cm-' whereas only background absorption was detected in this region of the spectrum of EXWL.…”

Section: Chemical Composition Of Exwlmentioning

confidence: 99%

Characterization of aspen exploded wood lignin

Marchessault¹,

Coulombe²,

Morikawa³

et al. 1982

Can. J. Chem.

114

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Exploded wood lignin (EXWL) was extracted from moist steam hydrolysed aspen (Populustremuloides) wood using methanol. The lignin was examined by elemental analysis, gel permeation chromatography, infrared spectroscopy, proton and 13C nmr. The observed nmr spectra were compared with those of aspen milled wood lignin (MWL). Typical composition of the material is C9H9.2O2.7(OCH3)1.1 Assignment of all the signals in the nmr spectrum led to the conclusion that the explosion process causes cleavage of the β-aryl-ether bond. The weight average molecular weight was found to be 1700–1900 and the polydispersity 2.6. The finely divided exploded wood was soluble in 90% methanol/water mixtures to well beyond 20% by weight at room temperature.

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“…There are several methods available for the determination of carbonyl group in lignins using advanced instruments, which include Fourier Transform Infrared (FT-IR) spectroscopy [16,17], 19 transform Raman (NIR-FTR) spectroscopic technique [19]. The major problems in these instrumental analytical methods are the precision and accuracy in the carbonyl group measurement, especially for the samples with complicated matrices.…”

Section: -Comentioning

confidence: 99%

“…a simple method based on measuring the hydrogen volume released from Reaction (2) after Reaction (1) was proposed [15,16]. At the suggested conditions, it requires 5 h to complete Reaction (1).…”

Section: -Comentioning

confidence: 99%

Rapid method for determination of carbonyl groups in lignin compounds by headspace gas chromatography

Chai

2015

Journal of Chromatography A

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Carbonyl Groups in Lignin. IV. Infrared Absorption Studies and Examination of the Volumetric Borohydride Method.

Cited by 33 publications

References 0 publications

Review: Light-Induced Yellowing of Lignocellulosic Pulps – Mechanisms and Preventive Methods

Review: Light-Induced Yellowing of Lignocellulosic Pulps – Mechanisms and Preventive Methods

Characterization of aspen exploded wood lignin

Rapid method for determination of carbonyl groups in lignin compounds by headspace gas chromatography

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