Excellent tribological and anti-corrosion performance of polyurethane composite coatings reinforced with functionalized graphene and graphene oxide nanosheets

Abstract

ABSTRACT： ： ： ：In order to improve mechanical durability, polyurethane (PU) needs to be modified to enhance tribological and anti-corrosion properties. In this work, we fabricated a series of PU composite coatings reinforced with functionalized graphene (FG) and functionalized graphene oxide (FGO). The structural and morphological features of the composite coatings were characterized by Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray diffraction, transmission electron microscopy and scanning electron microscopy. Results showed that the dispersion and compatibility of graphene and graphene oxide were improved via chemical modification. Moreover, they effectively enhanced the tribological and anti-corrosion properties of PU composite coatings, whose optimized additive range were between 0.25wt% and 0.5wt%. The effect depends on the balance of lubrication and barrier of fillers and cracks generated by them. Finally, in comparison with FG/PU coatings, FGO/PU coatings exhibited better tribological property but worse anti-corrosion property owing to abundant oxygenated groups of GO. They lead to stronger interfacial interaction between FGO and PU matrix, but destroyed the graphene lattice structure to some extent.

Development and Characterization of Anticorrosion and Antifriction Properties for High Performance Polyurethane/Graphene Composite Coatings

“…Therefore, Gr can play an essential role in improving the anticorrosion and antifriction properties of polymer coatings. Although a few studies have reported that the anticorrosion and antifriction properties of polymer coatings can be simultaneously altered using Gr additives [38][39][40], the Gr contents employed in those works were relatively low. Moreover, the COF of composite coatings used in those studies increased rapidly to a higher value (over 0.5) after a short sliding distance and the impedance modulus of the composite coatings at the lowest frequency in the Bode plot decreased with the passage of measurement time under immersion in 3.5 wt.% NaCl solution.…”

“…To study the effect of Gr addition on the corrosion resistance of PU coatings, equivalent electric circuits were used to interpret the measured impedance data. In this study, equivalent electric circuits ( Figure 3) were employed to fit the measured Bode plots by using the ZSimpWin software [38,39,48]. R s denotes the solution resistance.…”

“…The addition of high-performance nanofillers, such as ceramic particles into polymer coatings, is effective in enhancing their antifriction properties. Notably, recent investigations have revealed the significant potential of Gr and its derivatives for producing polymer composite coatings with high antifriction properties [38][39][40][41][42]. For instance, Mo et al [38] investigated the tribological performance of PU composite coatings reinforced with functionalized Gr (FG) and Gr oxide (FGO) and found that FG and FGO enhanced the antifriction property of PU composite coatings owing to their lubricating effects.…”

“…Many mechanical properties of polymer materials, such as mechanical strength [35,36], tribological performance [37][38][39][40][41][42], thermal stability [19] and electrical conductivity [43,44], can be improved remarkably by incorporating carbon derivatives into polymers. In particular, the antifriction performance of polymer coatings is of practical importance because these coatings are susceptible to damage through scratching and abrasive wear under outdoor service conditions, leading to the loss of mechanical strength.…”

Development and Characterization of New Coating Material of Blended Epoxy-Lacquer with Aluminum

“…The porosity value first decreased to the minimum of 2.7 × 10 −7 and then began to increase with the further decrease of Al mass fraction. With the decrease of the Al mass fraction from 40% to 30%, the state of Al particles changed from aggregation to uniform distribution, which may lead to a denser coating structure and decrease the porosity, thereby decreasing the NaCl solution penetration and increasing the corrosion resistance [24]. When the Al mass fraction was decreased from 30% to 10%, the morphology of the coating changed from the continuous particle contact state to the independent particle state, and thus the mixture was more loose (Figure 1).…”