Epoxy/poly(ethylene-co-methacrylic acid) blends as thermally activated healing agents in an epoxy/amine network

Thermally activated healing of a cured epoxy/amine network using di-glycidyl ether of bis-phenol A (DGEBA) and triethylene-tetramine (TETA) was explored using a modified thermoplastic poly(ethylene-co-methacrylic acid) (EMAA) healing agent. Epoxy resins of differing molecular weight were blended and pre-reacted with EMAA to heal via covalent and non-covalent bonding. Healing depended strongly on compatibility and reactivity between the epoxy additive and EMAA. Reduced compatibility and preferential miscibility produced the greatest healing, while increased compatibility and epoxide chemical reaction reduced healing. More healing was achieved when the availability of reactive epoxide groups from the healing agent and amino groups from the amine rich DGEBA/TETA polymer networks both increased.