Novel core-shell double microcapsules synthesize via inverse Pickering emulsion polymerization for self-healing of epoxy resin compounds

Microcapsules loading with healing agents are constantly used in engineered self-healing materials. But the synthesis of epoxy resin composites with excellent self-healing effect remains a major challenge. In this paper, 3-(Trimethoxysilyl)propyl methacrylate (KH570) was used to modify the nano silica (KHSI) for increasing lip-ophilicity. Then by using water-in-oil method, the inverse Pickering emulsion was stabilized by KHSI, and the core-shell double microcapsules (CS-DMics) loaded with different healing agents were formed via 1,1-Bis(acryl-oyloxymethyl)ethyl isocyanate (BEI). SEM and particle size statistical show that the size range of CS-DMics is 10-149.25 mu m. Ultimately, the self-healing epoxy resin compound (Sh-ERC) was acquired by combining CS-DMics with epoxy resin substrate materials. The thermal properties, mechanical properties, self-healing prop-erties and electrical conductivity were tested. It is found that Sh-ERC has perfect self-healing performance when the cracks occur and the microcapsules release healing agent for repairing. The self-healing effect of Sh-ERC is better with more CS-DMics content, and the self-healing efficiency is up to 86.5% when the content of CS-DMics is 40%. It has an excellent self-healing performance for engineering materials.