Formaldehyde-free dimethoxyethanal-derived resins for wood-based panels

Here we report on the results of a research project focused on the reduction of formaldehyde emissions from wood-based panels, by using a novel set of adhesive formulations based on dimethoxyethanal (DME)-derived resins. The investigated adhesives were evaluated on laboratory scale in order to study their technical performances, their gluing parameters, their reactivity as well as their formaldehyde emissions. It was found that all formulations met the requirements of the current standards EN 319:1993-08 and that for class P2 particleboards for general uses. From the technical point of view, major advantages of the resin systems tested were found to be: colorless, low toxicity, easy handling, and high stability at room temperature (long shelf-life, pot-life and open-time). The formaldehyde emissions of the boards produced were found to be comparable to those of natural wood (F****JIS A 1460:2001 standard). The laboratory results obtained with these formulations were validated on industrial scale. The technical properties as well as the formaldehyde emissions were measured. The new formulations were shown to be able to satisfy the requirements of standards with very low levels of formaldehyde emissions. However, to fulfill the requirements of the wood industry, the reactivity of the adhesive needs to be enhanced.