Preparation and Property Investigation of Epoxy/Amine Micro/Nanocapsule Based Self-healing Coatings

Abstract

Abstract Autonomous self-healing was achieved by synthesizing epoxy coatings which contain dual micro/nanocapsules; epoxy and amine. Epoxy micro/nanocapsules were prepared by an in situ polymerization process and amine microcapsules were fabricated by vacuum infiltration of diethylenetriamine into nanoporous hollow glass microspheres. Both types of capsules were embedded into epoxy matrix. When cracks were created and started to grow in the coating, the micro/nanocapsules near the crack were ruptured and released their contents. As a result of curing reaction between released curing agents (epoxy and amine), healing of the cracked sites was completed. In this work, some properties of epoxy/amine micro/nanocapsule based self-healing coatings such as morphology of micro/nanocapsule and coating, healing and corrosion properties were studied. Also thermal stability and adhesion properties of this kind of coating were evaluated comprehensively. It was found out that optimum mass ratio of epoxy/amine capsules ratio is 1 : 1 and the highest healing efficiency was achieved for a total micro/nanocapsule concentration of 15 wt.%. Regarding thermal and adhesion behavior of coatings, it was observed that adding micro/nanocapsules to epoxy matrix did not change these properties significantly which means self-healing characteristics were achievable without deteriorating other properties.