Enhancement of anticorrosion resistance of a fluorinated polyimide matrix by incorporating self-fixing POSS-GO.

In this study, we aimed to enhance the anticorrosion performance of composite coatings by introducing polyhedral oligomeric silsesquioxane (POSS)-grafted graphene oxide surfaces. These surfaces were modified to achieve super-hydrophobicity and a self-fixing effect. The modified material was employed to enhance the corrosion resistance of fluorinated polyimide (FPI) composite coatings composed of graphene oxide (GO) grafted by POSS (POSS-GO). The resulting composite coating exhibited substantially improved corrosion resistance compared to a pure FPI coating. The impedance modulus (|Z| 0.01 Hz) of the 0.3 wt% FPI/POSS-GO coating was approximately 2.57 × 1011 Ω·cm2, which was greater than that of the pure FPI coating by approximately five orders of magnitude. The enhanced performance can be attributed to the synergistic interaction between the intrinsically hydrophobic polyimide matrix polymer, which acts as a barrier, and the POSS-GO fillers with their superhydrophobic and self-fixing characteristics. Notably, these properties remained effective even after subjecting the coatings to a 3.5 wt% NaCl solution during a 45-day salt spray test. These findings have significant implications for the development of cost-effective anticorrosion coatings for metal substrates. In this study, we successfully developed a 0.3wt%FPI/POSS-GO composite coating by spraying method, and cured upon high-temperature thermal imidization. Furthermore, the |Z| 0.01 Hz value of 0.3wt%FPI/POSS-GO coating was 1.14 × 1011 Ω·cm2, after a 45-day neutral salt corrosion test. The excellent corrosion resistance of the composite coatings was attributed to the improved barrier property provided by the well-dispersed POSS-GO with self-fixing and hydrophobicity. Last but not least, we could boldly predict that this is a long-term corrosion resistant coating that can be applied in complex service environments, such as marine, alternating wet and dry. [Display omitted] • A fluorinated polyimide-based super anti-corrosion coating was prepared. • An appropriate amount of POSS-GO effectively improved the compactness and heat resistance of the coating. • The self-fixing effect of POSS-GO promotes its dispersion stability in FPI resins, providing better barrier performance. • The FPI/POSS-GO composite coating holds great potential for long-term corrosion protection. • Anti-corrosion mechanisms of the coatings were revealed. [ABSTRACT FROM AUTHOR]