Development and characterization of eco-friendly particleboard composites reinforced with recycled polystyrene and bonded with bio-based polyurethane

Due to the growing demand for environmentally friendly materials, there has been an increase in research into the reuse of industrial and post-consumer residues in engineered wood products. Consequently, the present study evaluates particleboard composites made from pine (PT) and eucalypt (ES) wood waste remnants bonded with castor oil-based polyurethane (PUR) and reinforced with recycled polystyrene (PS). A particleboard was manufactured by hot pressing and its physical, mechanical, morphological, and thermal properties were determined. By incorporating PS, moisture resistance, dimensional stability, and thermal properties were significantly improved. According to mechanical tests, the modulus of rupture (MOR) and modulus of elasticity (MOE) increased with increasing PS content, while the perpendicular tensile strength (PTS) decreased but remained above the minimum required by NBR 14810–1 of 0.35 MPa. The PT-ES/PUR composite containing 50 wt% PS exhibited the best overall performance, achieving MOR and MOE values of 24.40 MPa and 3.150 GPa, respectively. Additionally, this formulation showed reduced thickness swelling (9.65 %) and water absorption (24.04 %) when compared with the PS-free specimen. By scanning electron microscopy, it was demonstrated that higher PS concentrations resulted in improved interfacial adhesion and a more effective polymeric encapsulation of wood particles. Based on thermogravimetric analysis, PS acts as a thermal barrier, delaying lignocellulosic degradation and enhancing the thermal stability of composites. Based on these results, it has been demonstrated that recycled PS can reinforce and reinforce, thereby contributing to the development of sustainable particleboards that can be used for indoor and semi-exposed applications, such as furniture components. • PS reinforcement improves mechanical strength and dimensional stability of composite. • Particleboard reach up to 3.15 GPa MOE with 50 % recycled PS content. • PS addition reduces water absorption and thickness swelling after 24 h. • Particleboard with PS show higher thermal stability and interfacial adhesion.