Preparation of high-performance PEEK anti-wear blends with melt-processable PTFE

Abstract

High-performance anti-wear polyetheretherketone/polytetrafluoroethylene (PEEK/PTFE) blends have drawn much attention over the past few years, owing to their wide range of potential applications. However, a convenient and effective method to prepare such blends with superior mechanical and tribological properties is still lacking. In this work, we propose a promising approach that uses melt-processable PTFE (MP PTFE), instead of conventional PTFE, to prepare anti-wear blends. MP PTFE, with melt flow abilities under appropriate conditions, can disperse homogeneously in PEEK, enhancing both the mechanical and tribological properties of the PEEK/PTFE blend. To prove this postulation, in this work, both MP PTFE and commercial PTFE were blended with PEEK, separately, and the effects of PTFE type and content on the tensile and tribological properties of the blends were studied. The results showed that, although the addition of commercial PTFE to PEEK could increase the wear resistance, it decreased the tensile strength of PEEK significantly. Compared to the blends with commercial PTFE, the blends with MP PTFE exhibited better tribological performance and higher tensile strength for PTFE content below 10 wt%. It was confirmed that the better dispersion of MP PTFE in PEEK endowed the blends with higher tensile strength. The surface analysis indicated that the MP PTFE could readily migrate to and enrich the surfaces of the blends. The relatively high PTFE content on the surface favored the formation of tribo-films, enhancing the tribological properties of the blends.

Controllable design of polytetrafluoroethylene chemical component using the “harmful” irradiation heat

“…This was mainly explained by the formation of transfer film between the worn surface and the counterface during sliding, 49–51 which could prevent the POM/irradiated‐PTFE composites from direct abrasive wear, and resulted in the reduction of the friction coefficient and wear rate. As shown in Figures 4 and 5, fewer fluoride and oxygen‐containing groups were produced at 400 kGy than that at 1600 kGy in PTFE.…”

“…Meanwhile, the specific wear rates of POM/A1600 composites was also lower compared with that of POM/A400 composites, indicating that POM/A1600 composites exhibited better wear resistance than POM/A400 composites. This was mainly explained by the formation of transfer film between the worn surface and the counterface during sliding,[49][50][51] which could prevent the POM/irradiated-PTFE composites from direct abrasive wear, and resulted in the reduction of the friction…”

Tribological Behavior of PEEK/PTFE Composites Reinforced with Carbon Fibers and Graphite

“…PTFE is considered as one of the best fillers to improve wear resistance of PEEK-based composites. The main factor affecting the tribological performance is the formation of a transfer film on the wear track, which can reduce the friction coefficient by avoiding direct contact between the friction pairs [ 10 , 11 , 12 ]. However, this approach comes at the cost of decreased mechanical strength and an increased viscosity of the melted composite, which might limit their use under severe loading conditions.…”

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

“…As a typical representative of solid lubricants, polytetrafluoroethylene (PTFE) has attracted much attention for decades due to its very low friction coefficient. − For this reason, PTFE was widely used as a self-lubricant matrix or as an additive to prepare high-performance polymeric tribo-materials. − For instance, both powdery PTFE and fibrous PTFE have been proved to be effective in improving the tribological properties of PPS-based composites. − However, to the best of the authors’ knowledge, PTFE is a hard-to-process polymer with extremely high melt viscosity (near zero melt flow rate), which limits its good dispersion as an additive in the matrix by conventional melt processing methods. To obtain effective self-lubrication, it is necessary to increase the amount of PTFE added, which may be detrimental to the overall performance (e.g., mechanical properties) of the manufactured composite. , Therefore, it is the pursuit of researchers to get balanced properties of PPS composites at low PTFE content by uniform dispersion. Achieving a homogeneous dispersion of PTFE in a matrix is attractive and challenging but not easy unless the PTFE is melt-processable.…”

“…To obtain effective self-lubrication, it is necessary to increase the amount of PTFE added, which may be detrimental to the overall performance (e.g., mechanical properties) of the manufactured composite. 23 , 24 Therefore, it is the pursuit of researchers to get balanced properties of PPS composites at low PTFE content by uniform dispersion. Achieving a homogeneous dispersion of PTFE in a matrix is attractive and challenging but not easy unless the PTFE is melt-processable.…”