Reduction of Formaldehyde Emission and Bonding Performance of Plywood Using Poplar Bark Extractive as a Bio-Based Scavenger

Abstract

In the increasingly regulated environment where demand for natural and
sustainable materials is high, this research explores the potential of forestry's by-
product poplar-bark extractives as an environment-friendly, bio-based
formaldehyde scavenger for plywood manufacturing. In the present study, bark
extracts of poplar were collected, dried, and processed using an aqueous methanol
extraction technique that was optimized for extreme extraction of poly phenolic
constituents in poplar bark. The extract produced was subsequently incorporated
into UF resins at different levels of concentration starting from 0.5 to 5% on the
basis of resin weight. The different properties of adhesive and ply board like
viscosity, gel time, bonding strength, and formaldehyde emission was carried. The
experimental results highlighted the significance of the poplar bark extract for final
product environmental performance and mechanical properties. Among the
different formulations tested, the 5% concentration of bark extractives was
determined to have given the best balance between the lower formaldehyde
emission which was diminished by around 42% from that of the controlled UF
adhesive and some achievable bonding performance with acceptable glue shear
strength. Lower concentrations provided a moderate degree of reduced emission,
while higher concentrations affected bond formation and efficiency.
In general, the research on poplar bark extractives finalized a promising eco-
friendly and cost-effective alternative to reduce formaldehyde emissions in UF-
bonded plywood .