Influence of addition of PTFE on the tribological properties of CF reinforced plant-derived semi-aromatic polyamide (PA10T) biomass composites

To develop the new engineering materials such as structural materials and tribomaterials based on plant-derived materials, we investigated the influence of addition of polytetrafluoroethylene (PTFE) on the tribological properties of carbon fiber (CF) reinforced plant-derived semi-aromatic polyamide (PA10T) biomass composites. PA10T was a kind of polyphthalamide (PPA, semi-aromatic polyamide) and biomass polymer made from plant-derived decamethylenediamine and coal-derived terephthalic acid. PA10T was used as a matrix polymer. Various CF/PA10T/PTFE biomass composites were extruded using a twin screw extruder and injection molded. Tribological properties such as frictional coefficient, specific wear rate and limiting pv (pressure x velocity) value test by the step load method were measured by a ring on plate type sliding wear tester under dry condition against a carbon steel (S45C) ring. The wear debris were observed by scanning electron microscopy (SEM) for understanding the wear mechanisms. It was found the tribological properties such as frictional coefficient, specific wear rate, and limiting pv value improved when added with PTFE, although the mechanical properties of CF/PA10T/PTFE biomass composites are almost the same as those of CF/PTFE biomass composites. These results may be attributed to develop the new tribomaterials based on plant-derived polymer composites with sufficient balances among eco-friendliness, mechanical and tribological properties.