Effect of magnesium nanoparticles on formaldehyde emissions from wood composite materials

Abstract

For the production of wood composite materials, adhesives based on cheap and affordable, but harmful urea-formaldehyde resins are mainly used. Given the substantial production volumes of such materials, it is important to find environmental solutions to reduce formaldehyde emissions during their pressing and subsequent operation. The purpose of the study was to present the results of a study on the use of magnesium oxide nanoparticles to bind unreacted formaldehyde in wood composite materials. Analysis of methods for manufacturing metal nanoparticles allowed determining a priority method that allows obtaining ultrafine structures with a size not exceeding 100 nm, namely, the method of volumetric electric spark dispersion of metals in a liquid. Investigating the morphology of magnesium nanoparticles allowed determining that they have an almost crystalline form formed from the vapour phase, with an average particle length not exceeding 100 nm. The results of spectral analysis of the element composition in the nanophase, specifically magnesium and oxygen, demonstrated that the magnesium content does not exceed 32.2%, while oxygen constitutes 67.78%. This indicates that divalent magnesium oxide does not have a pronounced metallic phase, which would interfere with the sorption processes of formaldehyde. The conducted examinations of formaldehyde emission of samples of particle boards with modified magnesium oxide nanoparticles in concentrations of 2% and 8% glue based on urea-formaldehyde resin showed mixed results. Compared to the control samples, the formaldehyde level remained almost unchanged on the second day of follow-up, and for a concentration of 2%, it even increased by 6%. However, by the sixteenth and ninetieth day, a reduction in the level of free formaldehyde emissions was observed at 19% and 22% respectively. The results obtained can be used to improve the production of non-harmful particle boards with improved properties