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

Madihan Yusof; Junidah Lamaming; Mohamad Saiful Sulaiman; Ros Syazmini Mohd Ghani; Sofiyah Mohd Razali

doi:10.65582/rrs.2026.005

Authors

Madihan Yusof Centre of Excellence in Wood Engineered Products (CeWEP), University of Technology Sarawak, 96000 Sibu, Sarawak, Malaysia; School of Engineering and Technology, University of Technology Sarawak, 96000 Sibu, Sarawak, Malaysia,
Dr. Junidah Lamaming 2 Chemistry Programme, Faculty of Resource Science and Technology, Universiti Malaysia Sarawak, 94300, Kota Samarahan, Sarawak, Malaysia. https://orcid.org/0000-0003-2937-4295
Mr. Mohamad Saiful Sulaiman Centre of Excellent in Wood Engineered Products (CeWEP), University of Technology Sarawak, 96000 Sibu, Sarawak, Malaysia.
Ms. Ros Syazmini Mohd Ghani 4School of Postgraduate Studies, University of Technology Sarawak, 96000 Sibu, Sarawak, Malaysia https://orcid.org/0000-0002-0015-5606
Dr. Sofiyah Mohd Razali 5School of Foundation Studies, University of Technology Sarawak, 96000 Sibu, Sarawak, Malaysia https://orcid.org/0000-0001-5781-4871

DOI:

https://doi.org/10.65582/rrs.2026.005

Keywords:

Wood, flame retardancy, thermal stability, mechanical properties, binder

Abstract

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.