The Alcoholysis of Lignin

Brauns, Friedrich Emil; Brauns, Dorothy Alexandra

doi:10.1016/b978-1-4832-2779-5.50018-3

Cited by 6 publications

(8 citation statements)

References 26 publications

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“…It is well known that lignins can be alkylated under mild conditions by treatment with an alcohol and an acid catalyst (for literature, see Holmberg 1936;Adler and Gierer 1955;Brauns and Brauns 1960;Adler 1961;Marion and Adler 1963;Adler 1977). Alkylation studies have often aimed at an elucidation of the reactive groups in lignins.…”

Section: Introductionmentioning

confidence: 99%

Investigation of the Acid-Catalysed Alkylation of Lignins by Means of NMR Spectroscopic Methods

Adler¹,

Brunow²,

Lundquist³

1987

Holzforschung

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The acid-catalysed (catalyst, 0.15 M p-toluenesulfonic acid in the reaction medium) alkylation of lignins with rnethano) or ethanol in dioxane (alcohol-dioxane (2:1)) at 30°C has been studied by NMR spectroscopic methods. Complete alkylation required 4-6 days and resulted in the introduction of about one alkoxyl group in every second phenylpropane unit. The alkylation can be explained by etherification of benzy) alcohols (and, to a minute extent, cinnamyl alcohols), reetherification of benzyl ethers, esterification of carboxylic acids and formation of acetals from benzaldehydes, cinnamaldehydes and glyceraldehyde-2-aryl ethers. The methodology used permitted the conclusion that reactions other than alkylation occurred to only a minor extent. The wine-red colour acquired by the reaction mixture from lignin alkylation could be related to the occurrence of cinnamaldehyde groups. According to model compound studies, alkylation of arylglycerol-ß-aryl ethers resulted in a mixture of the erythro (60%) and threo (40%) forms of the benzyl ethers.

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Section: Introductionmentioning

confidence: 99%

Investigation of the Acid-Catalysed Alkylation of Lignins by Means of NMR Spectroscopic Methods

Adler¹,

Brunow²,

Lundquist³

1987

Holzforschung

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“…Lignin is only an aromatic-structured renewable, inexpensive and large-volume biomaterial from lignocellulosics (Brauns and Brauns 1960;Shen and Rosenholm 1998). Since lignin has highly irregular polymeric structure and recalcitrant nature, it is usually regarded as a waste product in industry.…”

Section: Introductionmentioning

confidence: 99%

“…Considering the fact that the lignin has ring structure with rich carbon components (Brauns and Brauns 1960), to develop lignin-based higher value products, e.g. the carbon film, carbon fibre, emulsion stabilizers and catalyst et al, have been recently highlighted (Frazier et al 1999;Rojas et al 2007;Shen and Zhong 2007;Dong and Shen 2009;Zakzeski et al 2010;Luo et al 2012;Ma et al 2014;Li et al 2015;Shao et al 2017).…”

Section: Introductionmentioning

confidence: 99%

“…the carbon film, carbon fibre, emulsion stabilizers and catalyst et al, have been recently highlighted (Frazier et al 1999;Rojas et al 2007;Shen and Zhong 2007;Dong and Shen 2009;Zakzeski et al 2010;Luo et al 2012;Ma et al 2014;Li et al 2015;Shao et al 2017). In these application cases, however, the lignin has been found unable to dissolve in water due to its aliphatic and aromatic structure (Brauns and Brauns 1960). Therefore, to do a pretreatment is usually required for applying the lignin.…”

Section: Introductionmentioning

confidence: 99%

“…There have several methods for dissolving lignin, e.g. the use of ionic liquid directly (Li et al 2010;Liu et al 2018), the sulfonation of lignin to form the soluble lignosulfonate (Brauns and Brauns 1960;Shen et al 2008;Dong and Shen 2009;Zhou et al 2010;Luo et al 2012) or the application of irradiation as the same as other polymers (Williams et al 1975;Campbell 1981;Charlesby 1981). Yet, the irradiation has been applied for modification of cellulosics (Dziedziela and Kotynska 1984;Leonhardt et al 1985;Phillips and Arthur 1985;Youssef et al 1996;Takacs et al 1999;Takacs et al 2000) and lignocellulosics (Khan et al 2006;Kuzina et al 2011).…”

Section: Introductionmentioning

confidence: 99%

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Quantitatively evaluation of the effects of γ-irradiation dose and time on the structure and properties of lignin

Cheng

Shen

2018

International Wood Products Journal

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The effects of γ-irradiation dose and process time on the structure and properties of alkali lignin have been quantitatively evaluated. According to the 13C CP/MAS NMR FTIR analyses, the γirradiation dose, D, and process time, t, on lignin structure have been known to break the side-chains of lignin, e.g. the C-β structure within the β-O-4, to enhance the C=O and C=C structure. By taking the NMR peak intensity of C=O structure, IC=O, and IR peak intensity of C=C structure, IC=C, as two measures, we obtained quantitatively relationships between D or t and those two lignin structures, respectively. Thermogravimetric analyses indicated that the lignin has an original thermal stability and its degradation was started since the applied dose at 300 kGy or the time up to 24 h at 100 kGy condition. The γ-irradiated lignin presented enhanced liquid adsorption due to the adsorbed water amount, Qt, increased with the D increase to follow a non-linear relationship.

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Der Einfluss von Kinetin auf die Ligninbildung und Differenzierung in Gewebekulturen vonNicotiana tabacum

Bergmann

1964

Planta

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The Alcoholysis of Lignin

Cited by 6 publications

References 26 publications

Investigation of the Acid-Catalysed Alkylation of Lignins by Means of NMR Spectroscopic Methods

Investigation of the Acid-Catalysed Alkylation of Lignins by Means of NMR Spectroscopic Methods

Quantitatively evaluation of the effects of γ-irradiation dose and time on the structure and properties of lignin

Der Einfluss von Kinetin auf die Ligninbildung und Differenzierung in Gewebekulturen vonNicotiana tabacum

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