Tribological Performance Studies of Waterborne Polyurethane Coatings with Aligned Modified Graphene Oxide@Fe₃O₄

Abstract

In this study, the chemical graft method was used to connect modified graphene oxide (GO) and Fe 3 O 4 through covalent bonds. To make full use of the tribological properties of graphene, aligned graphene oxide@Fe 3 O 4 /waterborne polyurethane (GO@Fe 3 O 4 /WPU) was prepared in a magnetic field and tribological experiments were carried out on it. The GO@Fe 3 O 4 was characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and a transmission electron microscopy (TEM). The characterization results show that Fe 3 O 4 is successfully loaded on the surface of GO and GO@Fe 3 O 4 has better dispersibility in WPU. Among the coatings without alignment inducement of GO@Fe 3 O 4 , 0.5 wt % GO@Fe 3 O 4 /WPU has the lowest friction coefficient and wear rate. In addition, the 0.5 wt % aligned GO@Fe 3 O 4 /WPU composite coating has the lowest friction coefficient and wear rate compared with nonaligned and pure WPU coatings. The excellent tribological properties of the aligned composite coating come from its ability to quickly form a uniform and continuous transfer film on the friction counterpair, which avoids direct friction between the friction counterpair and the coating.

Fe3O4 Nanoparticle-Decorated Graphene Oxide Nanosheets for Magnetic Assembly of Artificial Nacre

“…19-0629) . The sharp diffraction peak of 2θ = 10.6 for GO disappears after loading Fe 3 O 4 nanoparticles, showing that the interlayer distance expanded . The FT-IR spectra of GO, Fe 3 O 4 , and MGO are shown in Figure b.…”

“…GO nanosheets was modified with Fe 38 The sharp diffraction peak of 2θ = 10.6 for GO disappears after loading Fe 3 O 4 nanoparticles, showing that the interlayer distance expanded. 39 The FT-IR spectra of GO, Fe 3 O 4 , and MGO are shown in Figure 2b. The broad band at 3326 cm −1 represents hydroxyl group (−OH) stretching vibration.…”

A review of solid lubrication based on polyurethane composites

“…Moreover, the positive effects on tribological properties became more and more significant for PU coatings with increasing normal loads. Bai et al [91] used IPDI to modify GO and successfully grafted NCO groups onto the GO surface to obtain MGO. And the chemical grafting method was used to cooperate the NH 2 groups with the modified ferric tetroxide (named Fe 3 O 4 -KH550) particles by reacting with the NCO groups on the surface of MGO.…”

Improvement of Mechanical Properties and Solvent Resistance of Polyurethane Coating by Chemical Grafting of Graphene Oxide

“…However, physical blending will result in poor compatibility and dispersion of GO and WPU, and the modification ability of GO cannot be effectively exerted, which will easily cause stress concentration and get the opposite effect. The grafting method can organically combine GO with WPU through covalent and non-covalent bonds, and improve the compatibility and dispersion of GO in WPU [ 37 , 38 ]. Combining diisocyanate [ 39 ] or silane-functionalized [ 40 ] modified graphene oxide with WPU can improve the thermal, mechanical, and barrier properties of the coating [ 41 , 42 ].…”