Research Articles

Subterranean termites are major biological agents causing wood deterioration in tropical regions. Laboratory bioassays commonly use susceptible reference materials as controls to ensure termite feeding activity; however, information on the long-term variability of such materials remains limited. This study evaluated the variability and repeatability of Hevea brasiliensis (rubberwood) as a control material in laboratory tests involving Coptotermes curvignathus. Data from 27 independent trials conducted between 2016 and 2025 were analysed, with five replicates per trial exposed for four weeks using a standardized Forest Research Institute Malaysia in-house method. The mean density ranged from 0.584 to 0.701 g/cm³, while mean weight loss varied from 3.97% to 17.34%. The coefficients of variation for density, weight loss, and visual rating were 6.40%, 39.73%, and 13.11%, respectively. Weak correlations were observed between density and weight loss (r = 0.108), density and visual rating (r = −0.091), and weight loss and visual rating (r = −0.281). The results indicate that variability in feeding damage was primarily influenced by biological differences among termite colonies rather than wood density. Hevea brasiliensis was confirmed as a consistent and suitable control material for laboratory termite bioassays.

Poplar wood specimens were fabricated via surface swelling pretreatment with NaOH solution combined with a hot-pressing process. The three factors NaOH concentration, hot-pressing temperature, and hot-pressing time were considered relative to shear strength. The optimal process parameters for poplar adhesive-free bonding were surface swelling with 5% NaOH solution, a hot-pressing temperature of 140 ºC, and a hot-pressing time of 60 min. Under these parameters, the shear strength of the prepared specimens’ bonding interface reached 4.87 MPa. Analysis of variance showed that hot-pressing temperature exerted a highly significant effect on shear strength and that temperature was the dominant factor influencing adhesive-free bonding performance. Scanning electron microscopy observations indicated that NaOH solution surface swelling had a notable impact on the adhesive boundary, facilitating the formation of a dense adhesive layer in this area. Furthermore, a distinct phenomenon of molten lignin encapsulating fibers was observed at the bonding interface. As a natural bonding medium, molten lignin effectively enhances the bonding between fibers, thereby improving the adhesive-free bonding strength of poplar wood. Hemicellulose underwent substantial degradation, while no significant degradation was observed in the skeletal structure of lignin. This study provides a theoretical foundation and technical reference for optimizing the poplar wood adhesive-free bonding process.

Expanded polystyrene (EPS), widely used in plastic packaging, poses recycling challenges and contributes to environmental pollution due to its persistence. As an alternative, biopackaging materials were developed using mycelium from Ganoderma lucidum and agave bagasse (Agave tequilana Weber var. azul), a common agro-industrial residue in Jalisco, Mexico. The resulting materials showed a uniform, lightweight structure. SEM analysis confirmed full colonization of agave fibers by mycelium, indicating good cohesion. FTIR spectroscopy suggested intermolecular interactions between the fungal matrix and the lignocellulosic substrate. The material also exhibited hydrophobic behavior, as evidenced by its high water contact angle, indicating a surface with low wettability. In fire tests, the biopackaging burned slowly, emitted white smoke, and exhibited self-extinguishing behavior. Mechanical testing showed that the composites reached maximum force values in the same order of magnitude as EPS. Although flexural strength was slightly lower, the material tolerated greater deformation under comparable loads, indicating improved strain accommodation and resistance to abrupt fracture. Using the LIDS (Life Cycle Design Strategy Wheel), these materials were compared to conventional plastics, demonstrating advantages such as reduced reliance on petroleum-based polymers, valorization of agave waste, and alignment with circular production strategies in the tequila sector.