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
Xylan - A green binder for wood adhesives
KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.ORCID iD: 0000-0001-7132-3251
Show others and affiliations
2015 (English)In: European Polymer Journal, ISSN 0014-3057, E-ISSN 1873-1945, Vol. 67, p. 483-493Article in journal (Refereed) Published
Abstract [en]

Wood adhesives are mainly prepared from polymers derived from petroleum-based resources. With the increasing concern for the environment, it is necessary to find alternatives derived from bio-based resources that can replace petroleum-based polymers. To enable this transition it is important that the adhesive properties in terms of bond strength, water resistance and heat resistance are similar, and that the alternative can compete in terms of cost. Hemicelluloses are a byproduct from the pulp industry. From environmental and economic perspectives it is preferable to utilize all components from wood and decrease the amount of low-value byproducts. In this study, hemicelluloses are suggested to be used as binders in wood adhesives, why water dispersions of xylan have been prepared and evaluated. However, xylan itself cannot be used as a wood adhesive due to its limited bonding performance, especially regarding the water resistance. With the addition of dispersing agents, poly(vinyl alcohol) or poly(vinyl amine), and crosslinkers, such as glyoxal or hexa(methoxymethyl) melamine, the xylan dispersions demonstrate promising results. Wood veneers bonded with xylan dispersions and evaluated with ABES, Automated Bonding Evaluation System, demonstrate a good bond strength and surprisingly good water resistance. Several xylan dispersions fulfill the D1 and WATT 91 requirements for wood adhesives according to European Standards EN 204 and EN 14257, exhibiting good bond strength and heat resistance. Xylan dispersed in a poly(vinyl amine) solution also shows remarkable water resistance and reaches the threshold for the D2 criterion according to European Standard EN 204.

Place, publisher, year, edition, pages
2015. Vol. 67, p. 483-493
Keywords [en]
Wood adhesive, Polysaccharide, Hemicellulose; Xylan, Tensile shear strength, Water resistance
National Category
Polymer Technologies
Identifiers
URN: urn:nbn:se:kth:diva-171905DOI: 10.1016/j.eurpolymj.2015.02.021ISI: 000357750900046OAI: oai:DiVA.org:kth-171905DiVA, id: diva2:845477
Note

QC 20150812

Available from: 2015-08-12 Created: 2015-08-10 Last updated: 2018-05-21Bibliographically approved
In thesis
1. Hemicelluloses and other Polysaccharides for Wood Adhesive Applications
Open this publication in new window or tab >>Hemicelluloses and other Polysaccharides for Wood Adhesive Applications
2018 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The growing environmental awareness has led to an increased interest in bio-based polymers as replacement for fossil-based materials. The purpose of the work described in this thesis was to investigate the possibility of using hemicelluloses and other polysaccharides as replacement for fossil-based polymers in wood adhesives. Together with cellulose and lignin, hemicellulose is the main constituent of wood. In the pulp industry, significant amounts of hemicelluloses are obtained as by-products and combusted for energy recovery, but there is a growing interest in the biorefinery concept where all side-streams are utilized. If valuable applications, such as adhesives, of hemicelluloses and other by-products are found, large amounts can be obtained from the pulp industry. Water dispersions of hemicelluloses and other polysaccharides have been prepared and evaluated as adhesives for bonding different wood substrates together. The dry bond strength, water resistance, and heat resistance were investigated by exposing the bonded wood specimens to different conditioning methods and thereafter measuring the tensile shear strengths. As a replacement, the bio-based wood adhesive must possess similar or even better properties than the fossil-based adhesives. A commercial poly(vinyl acetate) (PVAc) wood adhesive used for indoor applications has been used as a reference benchmark. Wood hemicelluloses themselves do not have sufficient bonding performance probably because their low molecular weight does not provide adequate strength and makes the adhesive too brittle. The addition of dispersing agents and crosslinkers to the hemicellulose dispersions can significantly improve the bonding performance, and hemicellulose in combination with poly(vinyl amine) showed promising results superior those of PVAc. A fully bio-based adhesive comprising of hemicellulose and chitosan, another bio-based polysaccharide, obtain surprisingly good bonding performance especially with regard to water resistance. Gums, polysaccharides with similar structures to those of hemicelluloses but with higher molecular weights, have also been studied and locust bean gum dispersions without any modification showed a very good bonding performance with high dry bond strength and water resistance on a par with those of PVAc and a heat resistance superior to that of PVAc. Chitosan has very good adhesive properties especially with regard to water resistance, but the high viscosity of the chitosan dispersion makes it difficult to apply. Chitosan-grafted-PVAc dispersions were therefore prepared and an adhesive very similar in appearance to PVAc was obtained with a good bonding performance as well as good applicability.

Place, publisher, year, edition, pages
Kungliga Tekniska högskolan, 2018. p. 74
Series
TRITA-CBH-FOU ; 2018:22
National Category
Polymer Technologies
Research subject
Fibre and Polymer Science
Identifiers
urn:nbn:se:kth:diva-228298 (URN)978-91-7729-790-1 (ISBN)
Public defence
2018-06-11, Kollegiesalen, Brinellvägen 8, Stockholm, 14:00 (English)
Opponent
Supervisors
Note

QC 20180521

Available from: 2018-05-21 Created: 2018-05-21 Last updated: 2018-05-21Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full text

Authority records BETA

Fogelström, LindaMalmström, Eva

Search in DiVA

By author/editor
Norström, EmelieFogelström, LindaMalmström, Eva
By organisation
Coating Technology
In the same journal
European Polymer Journal
Polymer Technologies

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 394 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