Effect of addition of PP-g-MA on the tribological properties of hemp fiber reinforced plant-derived Polyamide1010 biomass composites

The aim of this study is to investigate the effect of addition of maleic anhydride grafted polypropylene (PP-g-MA) on the tribological properties of hemp fiber (HF) reinforced plant-derived polyamide 1010 (PA1010) biomass composites to develop the new engineering materials such as mechanical sliding parts (tribomaterials) based on inedible plant-derived materials. PA1010 was made from sebacic acid and decamethylenediamine, which are obtained from plant-derived castor oil. HF, which is one of the natural fibers, was used as a reinforcement fiber. HF was surface-treated by two types of surface treatment: (a) alkali treatment by sodium chloride (NaClO₂) solution and (b) surface treatment by ureidosilane coupling agents (A-1160). PP-g-MA (2wt.%) was used as a compatibilizer. These biomass composites were extruded using a twin extruder, and injection-molded. Tribological properties such as frictional coefficient and specific wear rate by ring-on-plate type sliding wear testing were evaluated. The wear debris were observed by scanning electron microscope for understanding the wear mode. It was found that frictional coefficient and specific wear rate improved when filled with PP-g-MA. This may be attributed to the change in the mode of wear mechanisms according to PP-g-MA uses or not.