Comparative Analysis of PVA-bonded Oil Palm Trunk and Rubberwood Composite Boards with NaCl and CaCO3 Additives

This study investigates composite boards fabricated from oil palm trunk (OPT) and rubberwood (RW) using polyvinyl alcohol (PVA) as a binder with sodium chloride (NaCl) and calcium carbonate (CaCO₃) as additives. Mechanical testing showed maximum bending strengths of 5.94 MPa (OPT) and 5.34 MPa (RW) at 10% PVA loading, while internal bonding values peaked at 0.97 MPa (RW). Dimensional stability improved with fillers, reducing thickness swelling by up to 25% compared to control boards. Flame retardancy was significantly enhanced, with LOI values exceeding 26% for all formulations containing NaCl and CaCO₃, classifying them as self-extinguishing. Thermogravimetric analysis confirmed improved thermal stability, with decomposition temperatures reaching ~543 °C in filler-modified boards. These findings highlight that integrating NaCl and CaCO₃ with PVA not only improves flame resistance but also enhances durability and thermal performance, demonstrating the potential of OPT and RW as sustainable raw materials engineered wood products.