A novel dual-functional epoxy-based composite coating with exceptional anti-corrosion and enhanced hydrogen gas barrier properties

Traditional hydrogen gas (H2) barrier polymer composite coatings or films suffered from poor corrosion resistance performance and low adhesion level, both of which could cause high risk of equipment failure and barrier property deficiency. Herein, a unique composite filler fabricated by hydrothermally in-situ grown hydrophobic CeO2 on glass flakes (GFs) was incorporated into epoxy resin (EP), followed by blade coating on different substrate, which facilitated orientation of GFs generated by shear force. The permeation of H2 and corrosive media could be dramatically decreased because of orientation-strengthened barrier and oxygen vacancies absorption effects. Additionally, interfacial interactions were also improved by means of covalent and hydrogen bonds between filler and polymer, reducing the free volume in EP and thereby further lowering gas diffusion. The CeO2 inhibition film and hydrophobicity property of composite filler prevent further penetration of corrosive media. Under the explicit and elaborate division of strengthening and inhibitive effects, the optimum sample demonstrated high impedance value 2 × 1010 ohm cm2 for 60d saltwater immersion and can tolerate 14d incessant harsh salt-spray test. It also exhibited 65.6% in H2 permeability coefficient reduction compared to pure EP coating and high adhesion strength of 6.35 MPa, which exhibits widespread industrial application prospect.