Modification of Poplar Wood with Different Resins: A Sustainable Solution for the Furniture Industry

Abstract

Poplar wood (Populus deltoides), a fast-growing and abundant species, holds promise for sustainable material use, but its low density, poor dimensional stability, and weak strength restrict high-value applications. This study examined property enhancement through resin impregnation with phenol-formaldehyde (PF), melamine-urea-formaldehyde (MUF), and polyethylene glycol (PEG) at 5%, 10%, and 15% concentrations. Modified specimens were tested for weight percent gain, bulking, water absorption, dimensional swelling, modulus of rupture, modulus of elasticity (MOE), impact strength, and surface hardness, as well as machinability and carving performance using expert evaluation and Computer Numerical Control (CNC) surface quality. Given the laboratory-scale dimensions of the specimens, the resins achieved satisfactory penetration, as also reflected in the WPG values. The 15% PF treatment produced the greatest improvements, yielding a WPG of 26.3%, MOE above 10,000 MPa, and reduced surface roughness to 2.90 µm. Compared with untreated samples, PF-modified wood showed superior dimensional stability, machining resistance, and carving clarity, approaching the properties of hardwoods such as walnut and beech. MUF led to moderate benefits, whereas PEG mainly caused bulk increase without significant strength or moisture resistance improvements. Overall, PF impregnation effectively upgraded poplar wood, indicating its potential as a cost-effective alternative for decorative and structural applications.