EFFECTS OF OIL PALM BIOMASS TYPE AND CONTENT ON THE PHYSICAL AND MECHANICAL PROPERTIES OF RECYCLED POLYPROPYLENE COMPOSITES FOR WOOD SUBSTITUTE APPLICATIONS

Abstract

This research aimed to enhance the value of recycled polypropylene (PP) by incorporating oil palm biomass, namely palm kernel shell (PM) and oil palm fiber (OPF), to develop composite materials for wood substitute applications in furniture manufacturing. The composites were prepared using an internal mixer at 170 °C and 60 rpm, followed by hot-press molding at 170 °C for 20 min. The effects of biomass type and content on the physical and mechanical properties of the composites were investigated, including density, water absorption, thickness swelling, modulus of rupture (MOR), modulus of elasticity (MOE), and screw withdrawal strength. The results showed that increasing PM and OPF contents led to higher composite density and water absorption. The PP60PM40 formulation exhibited the highest density of 1.03 g/cm³ and the highest MOR among the composite formulations at 43.81 MPa. The PP60PM20OPF20 formulation showed the highest thickness swelling of 1.79%. Nevertheless, all composite formulations exhibited water absorption below 0.35% and thickness swelling below 2%, indicating excellent dimensional stability. Comparison with Thai Industrial Standard TIS 966-2547 and Japanese Industrial Standard JIS A 5905 revealed that most formulations satisfied the requirements of JIS A 5905 in terms of density, thickness swelling, MOR, and MOE. The findings demonstrate that recycled polypropylene reinforced with oil palm biomass has considerable potential for the development of sustainable wood substitute materials, while simultaneously adding value to agricultural residues and supporting circular economy practices.