Anticorrosion performance of hydrophobic acid-modified-MOFs/epoxy coatings

• Published in: Colloid and interface science communications Vol. 46; p. 100580
• Main Authors: Wei, Runzhi, Liu, Zheng, Wei, Wenchang, Wang, Sheng, Lv, Yi-ju, Han, Guo-Cheng
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.2022
• Subjects: anticorrosive performance; Epoxy coating; NMOFs/OPA; super-hydrophobic; NMOFs/OPA; super-hydrophobic; anticorrosive performance; Epoxy coating
• ISSN: 2215-0382; 2215-0382
• DOI: 10.1016/j.colcom.2021.100580

Two nano metal-organic frameworks (NMOFs), [Cu(2,6-dmy-3,5-pyda)4]n (namely Cu-MOFs) and {[Zn(2,6-dmy-3,5-pyda)2(4,4′-bipy) (H2O)]•H2O}n (namely Zn-MOFs) with the unsaturated metal sites were hydrophobically modified by octadecylphosphonic acid (OPA) to prepare MOFs/OPA hydrophobic composites, which were added as hydrophobic additives to the epoxy (EP) coating to prepare Cu-MOFs/OPA/EP and Zn-MOFs/OPA/EP anticorrosion coating. The corrosion protection behavior of these coatings was examined in 3.5 wt% NaCl solution by using EIS, the capacitive arc of the coating modified with Cu-MOFs/OPA and Zn-MOFs/OPA was larger than EP, and Rp increases from 1.283 × 107 to 6.111 × 108 and 7.415 × 108, respectively. The two anticorrosion coatings showed higher impedance modulus values in low frequency region. All the study results proved that both Cu-MOFs/OPA and Zn-MOFs/OPA composite materials with the EP coating provided a very strong barrier and shielding effect, and have the ability to enhance the anticorrosive performance of the epoxy coating Epoxy resin, polyamide and MOFs with a mass ratio of 10:1:0.045 were added to an electric mixer to mix and continuously stir. During the stirring process, acetone was added in three portions, once every 30 min, and the addition amount was 5 mL. After stirring evenly, the polished carbon steel sheet was evenly coated with super-hydrophobic Cu-MOFs/OPA/EP and Zn-MOFs/OPA/EP anticorrosion coatings. [Display omitted] •Cu and Zn NMOFs were synthesized, OPA was used to modify the unsaturated metal sites.•The contact angles of the carbon steel surfaces coated with Cu-MOFs/OPA/EP and Zn-MOFs/OPA/EP coating were 156.6° and 159.7°.•The super-hydrophobic Cu-MOFs/OPA/EP and Zn-MOFs/OPA/EP coatings exhibited excellent anti-corrosion performance.