Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Fast and reliable quantification of lignin reactivity via reaction with dimethylamine and formaldehyde (Mannich reaction)
KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. Innventia AB, Sweden.
KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. Innventia AB, Sweden.
2017 (English)In: Holzforschung, ISSN 0018-3830, Vol. 71, no 1, p. 27-34Article in journal (Refereed) Published
Abstract [en]

The influence of pH on the Mannich reaction (amino alkylation in the presence of formaldehyde) has been analyzed by liquid chromatography-mass spectrometry (LC-MS) with vanillin (VA) as a model compound and a purified softwood kraft lignin (SKL) as a substrate. The reaction products of VA were studied at pH 5, 7, and 9 at 60 degrees C for 4 h. The Mannich adduct and side reaction products with methylene bridge were found at both pH 7 and 9, while only di-substituted by-products were observed at pH 5. Nitrogen contents determined from blank runs were substantial at pH 5 and negligible at pH 7. In VA or SKL, the resulting N-contents at pH 7 corresponded to a 76 or 62 mol% of the theory, respectively, i.e. based on the available C-5 positions in phenolic guaiacyl units (G-units). In the case of SKL, P-31-NMR analysis confirmed a 77% conversion of all phenolic G-units into their C-5 substituted derivatives. The Mannich reaction should be performed on lignin at pH 7 for 1 h to suppress unwanted side reactions, which could be observed by LC-MS under other pH conditions. The reaction is suitable for fast and reliable determination of reactive C-5-positions in lignin by multiplication of the N-content of the reaction products with a factor of 1.6.

Place, publisher, year, edition, pages
Walter de Gruyter, 2017. Vol. 71, no 1, p. 27-34
Keywords [en]
LC-MS, lignin, Mannich reaction, nitrogen content, pH dependence, phenol-formaldehyde (PF) resin, P-31-NMR, reactivity
National Category
Other Chemistry Topics
Identifiers
URN: urn:nbn:se:kth:diva-200404DOI: 10.1515/hf-2016-0054ISI: 000391191600004Scopus ID: 2-s2.0-85008709552OAI: oai:DiVA.org:kth-200404DiVA, id: diva2:1069136
Note

QC 20170127

Available from: 2017-01-27 Created: 2017-01-27 Last updated: 2017-09-11Bibliographically approved
In thesis
1. Physical, Chemical and Biochemical Modifications of Industrial Softwood Kraft Lignin for Different Applications
Open this publication in new window or tab >>Physical, Chemical and Biochemical Modifications of Industrial Softwood Kraft Lignin for Different Applications
2017 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Various technical lignins, e.g. industrial Softwood Kraft lignin (SKL), are now largely available while they are generally underutilized due to their heterogeneous and complicated structures and/or the poor properties. SKL has here been modified by physical, chemical and biochemical methods for preparation of lignin microspheres, phenol substitution in phenol-formaldehyde (PF) resin preparation and preparation of highly efficient fertilizers.

Physically, a brand-new slow and exhaustive solution evaporation process was developed for the highly efficient and productive preparation of microsphere structures. Highly homogenous SKL hollow microspheres were obtained and for the first time, urea encapsulating SKL microspheres were similarly prepared which could be an excellent controlled release urea fertilizer.

Chemically, Mannich reaction (one type of amination) was deeply investigated by including for the first time an LC-MS study of vanillin reaction, resulting in the establishment of a fast and reliable lignin reactivity (for phenol substation in PF resin) quantification method. In addition, SKL was functionalized using the Mannich reaction or esterification, leading to an improved hydrophobicity and compatibility for blending with polylactic acid (PLA). Using dip-coating technique for the first time, PLA-functionalised SKL-coated urea pellets were prepared, leading expectedly to a highly efficient urea fertilizer with simultaneous controlled- and slow- release and biological stabilization effects.

Biochemically, SKL was demethylated via incubation with different laccase-mediator combinations, which in principle will increase its reactivity in PF resin preparation. However, polymerization occurred which would decrease the reactivity.  The overall effects need to be further investigated.

Conclusively, broader or larger scale SKL applications can expectedly be realized after the development of SKL modifications tailored towards the optimum desired structures and properties.

Place, publisher, year, edition, pages
KTH Royal Institute of Technology, 2017. p. 83
Series
TRITA-CHE Report 2017:34, ISSN 1654-1081
National Category
Polymer Chemistry
Research subject
Chemistry
Identifiers
urn:nbn:se:kth:diva-213985 (URN)978-91-7729-492-4 (ISBN)
Public defence
2017-09-18, Kollegiesalen F3, Lindstedtsvägen 26, Stockholm, 10:00 (English)
Opponent
Supervisors
Note

QC 170912

Available from: 2017-09-12 Created: 2017-09-07 Last updated: 2017-10-05Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full textScopus

Search in DiVA

By author/editor
Wang, MiaoLi, Jiebing
By organisation
Fibre and Polymer Technology
Other Chemistry Topics

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 102 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf