Xylan – A green binder for wood adhesives. (June 2015)

• Record Type: Journal Article
• Authors: Norström, Emelie; Fogelström, Linda; Nordqvist, Petra; Khabbaz, Farideh; Malmström, Eva
• Is Part Of: European polymer journal. Volume 67(2015:Jun.)
• Page Start: 483
• Page End: 493
• Publication Date: 2015-06
• Subjects: PVA poly(vinyl alcohol) -- PVAm poly(vinyl amine) -- HMMM hexa(methoxymethyl) melamine -- AATMP trimethylolpropane triacetoacetate -- CA citric acid -- BTCA butanetetracarboxylic acid -- PVAc poly(vinyl acetate) -- pTSA toluene-4-sulfonic acid monohydrate -- ABES Automated Bonding Evaluation System -- RH relative humidity; Wood adhesive -- Polysaccharide -- Hemicellulose -- Xylan -- Tensile shear strength -- Water resistance; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; Polymerization; Polymers; Periodicals; Electronic journals; 547.705
• DOI: 10.1016/j.eurpolymj.2015.02.021
• Languages: English
• ISSNs: 0014-3057

Abstract

Graphical abstract: Highlights: Xylan can be used as the major component in wood adhesives. Xylan dispersions can successfully be classified as D1 and WATT 91 adhesives. Xylan dispersed in PVAm demonstrates surprisingly good results regarding water resistance as well as heat resistance. Abstract: 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.