The effect of coupling agents on the mechanical and physical properties of oil palm empty fruit bunch-polypropylene composites

Oil palm empty fruit bunch–polypropylene (EFB-PP) composites have been produced using a twin-screw extruder as the compounding equipment. Two levels of EFB were employed, 40 % and 60 % of the total weight of the sample. Three types of coupling agent, maleic anhydride-modified polypropylene (commercial name Epolene E-43), polymethylene(polyphenyl isocyanate) (PMPPIC) and 3-(trimethoxysilyl)-propylmethacrylate (TPM), were used. Overall, all coupling agents imparted considerable improvements in the flexural properties, E-43 showing the highest enhancement. However, only E-43 was observed to improve impact strength and tensile properties of the composites. All composites with coupling agents showed lower water absorption and thickness swelling. The absorption and swelling decreased as the loading of the coupling agents was increased.