Palm kernel shells (PKS) treated by commercial sodium bicarbonate (SB) filled recycled high-density polyethylene (rHDPE) were produced using melt compounding. These environmentally friendly composites were prepared using twin-screw extruder by varying untreated and treated filler loading (0, 10 and 30 php). In this study, the tensile properties of untreated rHDPE/PKS and treated rHDPE/PKS-SB were investigated. The composites were subjected to tensile test and the fracture surfaces were observed under scanning electron microscope (SEM). The results showed that SB treatment improved the filler-matrix adhesion and interaction of composites. Meanwhile, the SEM micrographs on the fracture surfaces confirmed that SB treatment which may influence the tensile properties of these composites.
