Effect of surface modified nano-SiO2 particles on properties of TO@CA/SR self-healing anti-corrosion composite coating

At present, microcapsule technology can carry out intelligent self-healing for micro-cracks, so as to prolong the service life of the marine protective coating. However, after adding microcapsules, the properties of the coating itself, such as coating adhesion, distinctness of image, and mechanical properties, will be affected to a certain extent. In this paper, calcium alginate containing tung oil self-healing microcapsules (TO@CA) is dispersed in silicone rubber (SR) coating (TO@CA/SR) and the related properties of TO@CA/SR are tested. TO@CA/SR coating prepared with TO@CA average size of 63.84 mu m and the content of 10% (T-63-10%) has the optimal performance. At the same time, TO@CA/SR composite coating is enhanced and modified by filling inorganic nano-SiO2 to realize self-healing microcracks without affecting the mechanical properties. TO@CA with modified nano-SiO2 of 2% (T/SiO2-2%) has the best self-healing, corrosion resistance, and mechanical properties. It shows that Nano-SiO2 forms a 3D connected network with SR and a double network structure coupled with the silicon chain network. The reversible bonding between nano-SiO2 and SR or nano-SiO2 dissipates the mechanical energy effectively under external force, thus improving the mechanical properties of coating. This study is of great significance for offset the impact of the microcapsules on the mechanical properties of the coating as much as possible, so as to ensure good stability of the self-healing coating.

Automated summary

This paper investigates the silicone rubber coating containing self-healing microcapsules with tung oil and tests its properties. By adjusting the size and content of the microcapsules, as well as adding nano-SiO2, the self-healing and mechanical properties of the coating are improved. The study shows that the nano-SiO2 forms a double network structure with the silicone rubber, effectively enhancing the mechanical properties of the coating.