Hydroxymethylfurfural in wood adhesives: Using the strength of a giant in interior particleboards
Wood adhesives must meet various criteria in terms of technical suitability and economic feasibility [1]. Important requirements in this regard are a rapid cure speed and high reactivity. Previously, these properties were identified as remaining challenges in the manufacture of bio-based adhesive and still prevent a cleaner production of wood particleboards [2].
SUSBIND approach
Hydroxymethylfurfural (HMF) is a promising, bio-based chemical acting as a highly reactive compound in adhesives. HMF has earned the epithet of a (sleeping) giant of sustainable chemistry, a term playing on its anticipated high market potential as well as on challenges occurring in large-scale production. Previously, it was found that HMF acts as a key reactant in fructose-amine adhesives, leading to an increased reactivity [3]. As visualized in Figure 1, this increased reactivity is a result of the lower activation energy needed for the curing reaction of the SUSBIND adhesive (a fructose-HMF-bishexamethylenetriamine (BHT) system). The activation energy is defined as the minimum energy that is required for a reactive species (e.g. an uncured adhesive) to undergo a reaction (e.g. curing reaction).
Figure 1: Illustration of the activation energy (left) and activation energy of SUSBIND adhesive (Fructose-HMF(5%)-BHT) during curing reaction (right) [3]
Within the SUSBIND project, lab-scale particleboards were produced together with the industry partner Fritz EGGER GmbH & Co. OG to evaluate the potential of HMF as reactive compound in the SUSBIND adhesive. Figure 2 depicts a typical particleboard production process in lab-scale.
Figure 2: Workflow of the production of laboratory-scale particleboards
If you are would like to know more about lab-scale particleboard production, check out the video on SUSBIND board pressing at EGGER: https://www.youtube.com/watch?v=tUC60Z46tnE
Technical assessment of SUSBIND particleboards
An important process-related parameter in the production of particleboards is the so-called press factor. It is the time needed to cure 1mm of the panel cross section. As can be seen in Figure 3, typical laboratory-scale press factors lie in the range of 5-12 s/mm using hot press-temperatures of 180-240 °C. Many carbohydrate-based adhesives need longer press factors to reach the minimum requirements of the European standard EN312 (e.g. internal bond strength). This is a result of their reduced reactivity and cure speed. The internal bond strength is a quality parameter in the aforementioned European standard, which specifies the classification requirements of particleboards. It is indicated as a line at 0.35 N/mm2 in Figure 3. Particleboards bonded with the SUSBIND adhesive surpass P2 requirements of the European standard EN312. The detailed discussion of the particleboard testing will be published in an upcoming scientific article [5].
Figure 3: Internal bond strength of particleboards bonded with SUSBIND adhesive, compared to reported literature on carbohydrate- and/or HMF-containing adhesives [2], [4-5]
Contact:
DI Catherine Rosenfeld, BSc.
Junior Researcher, Area Wood Materials Technologies
Kompetenzzentrum Holz GmbH, WoodK+
E-Mail: c.rosenfeld@wood-kplus.at / Homepage: www.wood-kplus.at
References:
[1] Arias, A., González-Rodríguez, S., Vetroni Barros, M., Salvador, R., de Francisco, A. C., Moro Piekarski, C., & Moreira, M. T. (2021). Recent developments in bio-based adhesives from renewable natural resources. Journal of Cleaner Production, 314, 127892. doi:https://doi.org/10.1016/j.jclepro.2021.127892
[2] Solt;, P., Konnerth, J., Gindl-Altmutter, W., Kantner, W., Moser, J., Mitter, R., & van Herwijnen, H., W. G. ;. (2019). Technological performance of formaldehyde-free adhesive alternatives for particleboard industry. International Journal of Adhesion and Adhesives, 94, 99-131. doi:doi.org/10.1016/j.ijadhadh.2019.04.007
[3] Thoma;, C., Solt, P., Sailer-Kronlachner, W., Rosenau, T., Potthast, A., Konnerth, J., . . . van Herwijnen, H. W. G. (2021). Carbohydrate-hydroxymethylfurfural-amine adhesives: Chemorheological analysis and rheokinetic study. polymer, 231(124128).
[4] Rosenfeld;, C., Konnerth, J., Sailer-Kronlachner, W., Rosenau, T., Potthast, A., Solt, P., & van Herwijnen, H. W. G. (2020). Hydroxymethylfurfural and its Derivatives: Potential Key Reactants in Adhesives. ChemSusChem, 13(20), 5408-5422. doi:https://doi.org/10.1002/cssc.202001539
[5] Rosenfeld, C., Solt-Rindler, P., Sailer-Kronlachner, W., Kuncinger, T., Konnerth, J., Geyer, A., van Herwijnen, H.W.G. (2022). Effect of mat moisture content, adhesive amount and press time on the performance of particleboards bonded with fructose-based adhesive. submitted
