WOOD RESEARCH Volume 70, Number 3, 2025
IRYNA LYTVYN, NATALIYA BEKHTA, IRYNA KUSNIAK, PAVLO BEKHTA, and JÁN SEDLIAČIK

Properties of Particleboards with Partial Replacement of MUF Resin by Sodium and Magnesium Lignosulfonates

The objective of this study was to evaluate the feasibility of partially replacing melamine-urea-formaldehyde (MUF) resin with lignosulfonates and to assess the effects on the physical and mechanical properties of the boards. Particleboards were produced using MUF resin, with partial substitution by either sodium lignosulfonate (NaLS) or magnesium lignosulfonate (MgLS) at levels of 10%, 20%, and 30% by weight. Control boards were also manufactured using 100% MUF resin for comparison. The results demonstrated that both, the type and proportion of lignosulfonate, significantly influenced the physical and mechanical characteristics of the boards. Specifically, the lignosulfonate content had a notable negative effect on the internal bond (IB) strength, bending strength (MOR), and thickness swelling (TS). In contrast, the type of lignosulfonate significantly affected only the IB strength. Boards containing 10% NaLS exhibited comparable properties to those of the control group. Additionally, boards incorporating NaLS generally outperformed those containing MgLS, although the differences were not statistically significant. Particleboards incorporating with 10% or 20% NaLS or MgLS, although exhibiting lower IB strength, MOR and modulus of elasticity (MOE) than the control boards, met the performance criteria for type P2 boards, intended for interior applications (including furniture) in dry conditions, as specified by the EN 312.

WOOD RESEARCH Volume 67, Number 4, 2022
Mario Núñez-Decap, Gustavo Pérez-Soto, Alexander Opazo-Vega, Boris Moya-Rojas, and Marcela Vidal-Vega

Study of wood adhesives on the bonding properties in solid and hollow glulam beams of Pinus radiata

The aim of this research was study of polyurethane (PUR), isocyanate polymer emulsions (EPI) and melamine-urea-formaldehyde (MUF) adhesives, on the bonding properties of solid and hollow glulam beams of Pinus radiata. The thermomechanical analysis (DMA) of the adhesives was carried out to evaluate their stiffness and reactivity. Glulam beams were evaluated by a bending test. The quality of the bonding was evaluated by resistance to shear and delamination. The morphology of the bonding was studied by microscopy. The DMA study showed that the MUF adhesive had the highest level of stiffness and reactivity. The results of the bending test showed that the highest modulus of rupture results were obtained in solid and hollow laminated beams with MUF adhesive, achieving increases of 30% over the PUR adhesive. The lowest delamination results were obtained in solid glulam beams with MUF and EPI adhesives, while the highest results were 32% and 47% for the PUR adhesive. Finally, glulam beams manufactured with MUF adhesive presented the best performance and results.

WOOD RESEARCH Volume 64, Number 5, 2019
Jun Zhang, Lihong Xiong, Xiaojian Zhou, Guanben Du, Jiangkun Liang, and Xuedong Xi

Development of mimosa tannin-based adhesive cross-linked by furfuryl alcohol-formaldehyde and epoxy resins

A furfuryl alcohol-formaldehyde resin was synthesized as a crosslinker in our laboratory to develop a mimosa tannin-based adhesive with good water resistance. 13C nuclear magnetic resonance and matrix-assisted laser desorption ionization time-of-flight mass spectroscopy indicated that furfuryl alcohol reacted with formaldehyde under acidic conditions and that–CH (–OH) – groups to be the ones involved in the crosslinking of mimosa tannin-furfuryl alcoholformaldehyde adhesive (TFF). The wet shear strength of TFF-bonded plywood suggested that the cured TFF adhesive was better than mimosa tannin-furfuryl alcohol (TF) adhesive. The water resistance of TFF adhesive cross-linked with 9% epoxy resin was also higher than those of TFF and TF adhesives.