High-performance insulating epoxy Vitrimers: Facile modification enables ultra-high healing efficiency and closed-loop recycling

To develop an insulating epoxy Vitrimer exhibiting synergistic enhancement of intrinsic performance alongside recyclability under mild conditions, this study fabricates a system via a facile approach involving dipropylamine modification and a blend hardener system composed of methyl hexahydrophthalic anhydride (MHHPA) and glutaric anhydride. The optimized D-EP30/M75 epoxy Vitrimer, containing 30 mol% dipropylamine modifier and 75 mol% MHHPA hardener, exhibits outstanding properties: an electrical breakdown strength of 38.01 kV/mm, tensile strength of 68.4 MPa, glass transition temperature (T_g) of 104℃, and 93 % tensile strength healing recovery. Using ethylene glycol as a solvent at 130°C, all designed epoxy Vitrimers (2-mm-thick plates), including D-EP20/M100 with a T_g up to 117℃, are fully degraded within 9 h. The polyalcohols obtained via degradation (PAls) are suitable as feedstocks for epoxy resin and polyurethane preparation. This study establishes a simple and sustainable paradigm for high-performance insulating epoxy Vitrimers, integrating high healing efficiency and closed-loop recycling to address sustainability challenges, with significant promise for circular economy adoption.