Comparative study on the tribological properties of poly(arylene ether nitrile)/polytetrafluoroethylene composites: The influence of filler size and testing conditions

In this work, the influence of polytetrafluoroethylene (PTFE) filler size and testing conditions (i.e., air, water, and lubricating oil) on the tribological properties of poly(arylene ether nitrile) (PEN) was systematically investigated. The results showed that the addition of PTFE was beneficial to improve the tribological properties of PEN‐based composites which was related to the easier formation of transfer film on the surface of friction pair. Samples which were tested in water demonstrated a relatively higher friction coefficient (μ) and wear loss when compared with those tested in dry air and lubricating oil scenarios, which was attributed to the fact that friction induced heat and wear debris could be timely removed by water. In addition, the infiltration of water further reduced the interaction between PTFE filler and PEN, which aggravated the wear loss of sample blocks. When tested in lubricating oil, pure PEN showed the lowest wear loss when compared with that of PEN/PTFE composites. At a given content (20 wt%) of PTFE fillers, PEN/PTFE1.5μm exhibited the lowest μ in lubricating oil whereas PEN/PTFE5μm demonstrated the lowest specific wear loss in air condition (1.18 × 10−6 mm3/N·m). This work provided some useful information for the design and application of PTFE‐containing polymer composites that can be targeted in different lubrication scenarios in industrial fields. The addition of PTFE fillers was beneficial to improve the tribological properties of PEN‐based composites due to the easier formation of transfer film on the surface of the friction pair. Results also showed that the tribological performance of PEN/PTFE composites was affected by the type of PTFE fillers and testing environments.