Effect of Perfluoropolymers on the Anti-Wear Properties of Carbon Fiber/Polyphenylene Sulfide Composites: A Comparative Study

Abstract

In this work, several perfluoropolymers (PFP), including commercial polytetrafluoroethylene (PTFE), perfluorinated ethylene–propylene copolymer (FEP), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), and irradiated PTFE (iPTFE) were used as additives to lubricate carbon fiber (CF)-reinforced polyphenylene sulfide (PPS) composites. The tribological properties of the yielding composites were studied and correlated with the melt processability of PFPs. Although the neat FEP and PFA have higher friction coefficients when compared with neat PTFE, the composites filled with FEP and PFA additives were found to exhibit a lower friction coefficient compared to PTFE at PFP content below 10 wt %. Moreover, the iPTFE-filled composites also showed similar results as FEP or PFA filled ones, very different from PTFE at low additions. Based on the morphological investigation, we postulate that FEP, PFA, and iPTFE are melt-kneaded with PPS due to their melt processability at processing temperature, leading to the good dispersion in composites in the form of smaller deformed spheres and/or fibril bands. The well-dispersion of PFPs in composites promotes the formation and growth of the transfer film on the counterface during sliding.

Improving the tribological performance of polyphenylene sulfide by incorporating irradiation treated polytetrafluoroethylene powders

“…A comparison of both average μ and w for PPS‐based composites between this work and literature was displayed in Figure 4. The results indicated that PPS/i‐PTFE20 performed better when compared with the reported literature, which suggests that the use of irradiation treated PTFE powders was instrumental in improving the tribological performance of PPS‐based composites 18,19,21,22,50–56 …”

“…The EDS elemental analysis of the transfer film was depicted in Figure 8f and corresponding results were tabulated in Table 2. It was clear that there was a higher fraction of C and O on the sliding counterpart of PPS, which was likely related to the fact that severer tribo‐oxidation reaction occurred at the sliding interface 55 . Moreover, the content of F element on the surface of the sliding counterpart of PPS/i‐PTFE20 was 3.72%, which was a result of the formation of transfer film due to the adherence of i‐PTFE molecular chains to the friction pair.…”

“…The results indicated that PPS/i-PTFE20 performed better when compared with the reported literature, which suggests that the use of irradiation treated PTFE powders was instrumental in improving the tribological performance of PPS-based composites. 18,19,21,22,[50][51][52][53][54][55][56]…”

“…It was clear that there was a higher fraction of C and O on the sliding counterpart of PPS, which was likely related to the fact that severer tribooxidation reaction occurred at the sliding interface. 55 T A B L E 2 Elemental analysis of the transfer films for pure PPS and PPS/i-PTFE20. Moreover, the content of F element on the surface of the sliding counterpart of PPS/i-PTFE20 was 3.72%, which was a result of the formation of transfer film due to the adherence of i-PTFE molecular chains to the friction pair.…”