Advancing Sustainable Building Materials: Reducing Formaldehyde Emissions in Medium Density Fiber Boards with Lignin Nanoparticles

Abstract The pressing need to develop eco‐friendly polymer materials for building applications has led to increased interest in modifying existing polymer systems. In this study, a sustainable approach to augmenting urea‐formaldehyde (UF) resins, widely employed in wood‐based panels is introduced. Addressing this, formaldehyde‐scavenger demethylated lignin nanoparticles into UF resins, aiming to produce a green and enhanced medium‐density‐fiberboard (MDF) with minimal formaldehyde emissions is incorporated. The results indicate that increasing concentrations of demethylated lignin nanoparticles in the UF adhesive, there is not only a reduction in formaldehyde emissions from MDF composites but also a significant decrease in thickness swelling. The highest reduction in formaldehyde emission is observed in the MDF composite prepared with UF resin containing 7% lignin nanoparticles (UF‐7NL), with an emission of 2.9 mg/100 g, marking a substantial decrease of 74% compared to emission of 11.2 mg/100 g from neat resin. Importantly, this reduction does not compromise physical and mechanical properties of the MDF; they remain comparable to boards bonded with unmodified UF. Molecular modeling revealed that lignin effectively traps formaldehyde, incorporating it as ‐CH 2 OH groups, leading to a notable decrease in formaldehyde emission from MDF. This approach offers an eco‐friendly modification to a common polymer, showcasing lignin nanoparticles as innovative additives.