Mechanically strong and flame-retardant epoxy resins with anti-corrosion performance

Flame retardancy and corrosion resistance required by high-performance epoxy resins (EP), especially in the field of composites and coating, are difficult to achieve simultaneously. In this study, a facile method was put forward to impart both flame-retardant and anti-corrosive properties to epoxy resins, via chemically introducing bifunctional phosphorus-containing triazole derivatives (D-ATA). In the resultant epoxy thermosets, the phosphorylated triazole structure directly contributed to flame retardancy, while the triazole structure can effectively suppress the electrochemical corrosion. With only 5 wt% loading of D–ATA, the epoxy thermoset showed excellent flame retardancy with a high limiting oxygen index of 33.2%, V-0 rating in UL-94 tests and significant suppression of heat and smoke release in cone calorimetry tests. Meanwhile, the electrochemical corrosion tests confirmed that the corrosion protection efficiency of EP/5 wt% D-ATA increased by 95.3% in comparison to neat EP. Due to hydrogen bonding and π-π interactions caused by the introduction of D-ATA, the versatile epoxy thermoset also had enhanced mechanical properties with the improved tensile and flexural strength. Moreover, the anti-corrosion and flame-retardant mechanisms were also discussed in detail. This work provides a facial strategy for preparing versatile high-performance epoxy thermoset with fire safety and corrosion resistance for various applications.