Structure and tribological properties of Cu-PU-PTFE composite coatings prepared by low-energy electron beam dispersion with glow discharge

Abstract

Polytetrafluoroethylene (PTFE) composite coatings doped copper acetate and polyurethane (PU) were prepared on rubber substrate by low‐energy electron beam dispersion technique. The effects of dopant and glow discharge treatment on the surface morphology, structure and tribological properties of the coatings were investigated. The results showed that Cu–PTFE composite coatings form uniform surface and dense column structure with spherical aggregations under glow discharge treatment. PU coating shows the large size of protuberance structure but PU–PTFE coating presents spherical structure. Both of the coatings become relative dense and smooth after discharge treatment, and Cu–PU–PTFE composite coatings possess a smoother surface and lower polar component of surface energy. Cu doping weakens the crystallinity and ordering degree of composite coatings, but glow discharge increases the ordering degree and branched structure of C―H groups. Friction experiment indicated that Cu fails to improve the wear resistance of PTFE coatings but glow discharge treatment can do it. Cu–PU–PTFE coatings after discharge treatment have the higher wear resistance and lower coefficient of friction. Copyright © 2016 John Wiley & Sons, Ltd.

Modification of Cu‐PE‐PTFE composite coatings on rubber surface by low‐energy electron beam dispersion with glow discharge

“…Such coating is continuous at the thickness less than 0.6 mm, though the structure of the coatings adjacent the substrate cannot be identified by SEM. When the thickness exceeds 0.6 mm Cu-PE-PTFE composite coating forms the same microstructure to the Cu-PTFE coating obtained by electron beam dispersion [26]. These results indicate that the nature of the substrate determines the morphology of the composite coatings without discharge treatment, which may be due to the effect of interfacial adsorption processes on the formation processes of coatings structure.…”

“…In addition the variation of IR spectra of Cu‐PTFE coating compared to PTFE coating has been studied in the Ref. , and indicated the effect of Cu doping on molecular structure of polymer coatings. Therefore the observations on the IR spectra of composite coatings verify the intense chemical reaction between activated dispersion products by electron beam and glow discharge.…”

Peculiarities of Electron-Beam Formation of Hydrophobic and Superhydrophobic Coatings Based on Hydrocarbons of Various Molecular Weights and PTFE

“…The exposure of polymer materials to low-energy electron beam in vacuum is followed by formation of thin layers based on various macromolecular compounds, polytetrafluorethylene (PTFE) [21] in particular. The PTFE-based coatings are characterized by low surface energy, which allows using them as hydrophobic and antifriction layers [21,22]. The smoothed morphology of thin fluoroplastic layer is one of the causes for the lack of superhydrophobic properties of the layers formed: the water contact angle in most cases does not exceed 130°.…”