Frictional Properties of Tetrafluoroethylene-Perfluoro (propyl vinyl ether) Copolymers

Abstract

The Irictional properties of several new experimental random copolymers of tetrafluoroethylene and minor proportions of perfluoro (propyl vinyl ether) have been studied both as thick samples and as thin films on harder substrates. These copolymers have advantage over polytetrafluoroethylene (PTFE) in that they can be melted and made to flow, so that it should be possible to form water-resistant and melt-adhesive solid-lubricant films without the necessity of roughening the substrate or of using adhesive binders. For bulk samples, the kinetic coefficient of friction (µ^) of the new copolymers is considerably greater than that of PTFE. However, when applied as a thin film or a hard backing, the kinetic coefficient of friction is only 0.05-0.06.

A review: advancements in fluoro-based polymers for aggrandizing anti-galling and wear resistant characteristics

“…However PFA has comparable mechanical, thermal and chemical characteristics as PTFE, owing to this PFA has rarely been considered in tribological applications. The deficiency of tribology application of PFA composites is also due to the augmented cost as a comparison to PTFE [121][122][123]. Sidebottom et al [121] studied wear and frictional performance of PFA coating over PTFE coating.…”

Ultralow wear Perfluoroalkoxy (PFA) and alumina composites

“…This was significantly higher than the value of unfilled PTFE (µ~0.14). The reason for this difference in friction has been assigned to the perfluoroethoxy (C 2 F 5 O-) sidegroups in PFA 340 disrupting the smooth molecular profile of the linear fluoropolymer [29,64].…”

“…PFAs are a group of copolymers of TFE with small amounts of various types of perfluoroalkylvinyl ethers (alkyl = methyl [PMVE], ethyl [PEVE], propyl [PPVE]) which along with a chain transfer agent, decrease the molecular weight and increase the melt flow rate enough to enable injection molding (see Figure 1 for chemical structure) [27]. PFA has a larger coefficient of friction than PTFE but it is lower than many bulk polymers and can be used at a great range of operating temperatures [28,29].…”

Wear-Induced Microstructural and Chemical Changes in Poly[tetrafluoroethylene-co-(perfluoroalkyl vinyl ether)] (PFA)

“…Though it has similar mechanical, thermal, and chemical properties as PTFE, PFA has rarely been evaluated in tribological (friction and wear) applications, − which is peculiar considering PTFE is one of the most studied polymeric tribological materials. The lack of tribology research on PFA composites is likely due to the increased cost of PFA compared to PTFE.…”