High density polyethylene (HDPE)/palm kernel shell (PKS) composites were prepared through melt mixing by incorporating different PKS loading into HDPE matrix. PKS was chemically treated with stearic acid with the aim to enhance its compatibility with HDPE. The results showed that the addition of PKS into HDPE had decreased the melt flow index (MFI) values while the increasing of temperature help to increase MFI values of composites. It was discovered that stearic acid managed to increase the MFI values of composites. This was attributed to the improved dispersion of PKS in HDPE matrix. Besides, the differential scanning calorimeter results revealed that the presence of PKS had increased the crystallinity of HDPE/PKS composites because PKS was functioned as nucleation site. Fourier Transform Infrared spectroscopy had proven the success of stearic acid treatment on PKS surface.
