Self-Healing Polymeric Materials Using Epoxy/Mercaptan as the Healant

TLDR

A self‑healing system based on conventional epoxy resin was successfully developed. Epoxy and its hardener mercaptan were microencapsulated as a two‑component healing agent and embedded in the epoxy matrix. The system achieved high healing efficiencies (43.5 % with 1 wt % capsules, 104.5 % with 5 wt % capsules at 20 °C for 24 h), and the low capsule content allows a better balance between strength and toughness restoration; rapid self‑healing was enabled by the flowability, fast consolidation, and miscibility of the released epoxy‑mercaptan agent, yielding satisfactory repair effectiveness.

Abstract

A self-healing system based on conventional epoxy resin was successfully developed in this work. Epoxy and its hardener mercaptan were microencapsulated as two-component healing agent, and then the microcapsules were embedded in epoxy matrix. Attractive healing effect can be acquired at low capsule content (e.g., 43.5% healing efficiency with 1 wt % capsules and 104.5% healing efficiency with 5 wt % capsules at 20 °C for 24 h). Since only a few healant proves to be sufficient for crack repairing, a better balance between strength and toughness restoration can thus be achieved. As a result of high flowability, fast consolidation, and molecular miscibility of the released healing agent consisting of epoxy and mercaptan, self-healing was allowed to proceed rapidly offering satisfactory repair effectiveness.