Low infrared emissivity epoxy resin/Ag composite coating with outstanding mechanical properties and saltwater resistance

In this study, a low infrared emissivity coating with good mechanical properties and salt water resistance was prepared by the glass rod coating method, using epoxy resin, flake Ag powder, and graphene as a functional pigment, binder, and interface modifier, respectively. The study systematically investigated the impact of Ag powder particle size, as well as the addition of silver powder and graphene, on the coating properties. The larger particle size of the Ag powder led to a significant decrease in emissivity and enhancement of the mechanical properties of the coating. The coating had optimal emissivity and mechanical properties at an Ag particle size of 10 μ m. The emissivity and glossiness of the coating can be significantly reduced with the increase in added Ag powder, and the mechanical properties will be significantly improved. The increase in added graphene significantly reduced the glossiness and improved the flexibility of the coating. With a graphene content of 8 wt%, the coating has the best emissivity, glossiness, and mechanical properties at the same time. The epoxy resin/Ag composite coating, modified by graphene, showed good salt water resistance. After being corroded by salt water for 21 days, the emissivity, glossiness, adhesion strength, flexibility, and impact strength of the coating reached 0.535, 14.7, grade 1, 2 mm, and 50 kg · cm, respectively.