EFFECT OF ADHESIVE VARIATIONS: TAPIOCA, PVAC, MOLASSES AND CITRIC ACID ON THE PHYSICAL PROPERTIES OF PARTICLEBOARD

Abstract

Sustainability issues and the need for environmentally friendly materials prompted the utilization of biomass waste as an alternative raw material in composite panel manufacturing. The development of biomass-based composite boards not only reduced dependence on natural wood but also provided added value to agricultural and forestry organic waste. One of the main challenges was the application of safe and effective natural adhesives to replace formaldehyde-based synthetic adhesives, which are known to be harmful to the environment and human health. This study employed three adhesive formulations: citric acid with polyvinyl acetate (PVAc/Lem Fox), citric acid with molasses, and citric acid with tapioca, to investigate their effects on the physical and mechanical properties of composite boards. The panels were produced by hot pressing at 160°C and 3 MPa, then conditioned at room temperature for five days to ensure even moisture distribution. Property tests included measurements of moisture content (MC), density, modulus of elasticity (MOE), and modulus of rupture (MOR), all following the relevant SNI standards. The results showed that variations in adhesive formulation significantly affected board strength and stiffness. The combination of citric acid and PVAc yielded the lowest MOE and MOR values at 15.14 MPa and 1.0 MPa, respectively, indicating that these panels were less stiff and more susceptible to fracture due to suboptimal interparticle bonding and high moisture content. In contrast, the citric acid and molasses formulation achieved the highest MOE and MOR values at 41.25 MPa and 2.90 MPa, respectively, followed by citric acid and tapioca at 39.78 MPa and 2.60 MPa, along with more stable density and moisture content values.