Reversible hetero-Diels-Alder amine hardener as drop-in replacement for healable epoxy coatings

We describe a new amine-hardener that enables intrinsic thermally activated healing in epoxy-amine coatings. A hetero-Diels Alder (HDA) adduct bridges biosourced fatty acids and serves as the thermoreversible linker. We validated the thermal reversion of the adduct in solution and the HDA-containing diamine served as a drop-in replacement for commercial hardeners. Replacing commercial hardeners with bio-sourced fatty acids linked by hetero Diels-Alder (HDA) motifs enabled epoxy-amine coatings with intrinsic self-healing properties. The HDA-based coatings demonstrate scratch healing at 95 °C within 15 min.