Mechanical Properties of Poyurethane Composites From Oil Palm Resources

Abstract

Approximately 22% of waste from the oil palm industry consists of empty fruit bunch (EFB). This type of biomass along with a vast quantity of agricultural residues can be utilized in natural fibre-based composites. Previous studies on palm kernel oil have successfully turned it into a polyurethane polyol in producing natural oil-based polyurethane foam. The incorporation of different EFB fibre sizes at levels of 5.5% of 4556 µm, 4.5% of 100-160 µm and 2.5% of 200-315 µm in the foam has shown tremendous improvement in the mechanical properties of the composites compared to the control foam. The compressive strength increased by 11.1%, 11.6% and 29.1% for the 4556 µm, 100-160 µm and 200-315 µm fibre size, respectively. The 45-56 µm fibre size at 5.5% fibre loading showed the maximum compression strength and modulus. There is more tearing of cellular structure during expansion of the foams when larger size of fibres and larger amount of fibres are used. These lead to poor composite's strength. Micrographs of the cellular structure of the EFB-filled polyurethane foam showed that the presence of the fibrous EFB of size 200-315 µm torn the cellular structure, whereas the powder form of EFB filled the struts of the cellular network and enhanced the strength of the cell's wall.