Self-healing epoxy coatings with enhanced properties and facile processability

Self-healing coatings are endowed with the ability of self-repair upon damage, thus enhancing their lifetime. However, limited by the complex chemistry and composition design, the reported self-healing coatings have processing difficulties and undesired low mechanical properties. This work presents a self-healing epoxy coating system obtained by simply blending a commercial epoxy with a series of different molecular weight thermoplastic polyurethane (TPU) prepolymers. These systems display phase separated morphology induced through polymerization. They show extended shelf-life in comparison with the reported epoxy-polycaprolactone (PCL) self-healing system and comparable processing window with the commercial epoxy coatings. These coatings show remarkable transparency and mechanical properties by comparison with the epoxy-PCL system and fast healing performance with crack closure upon heating at 80 degrees C in 10 min. Moreover, the resultant closed crack undergoing the electrochemical corrosion test exhibits effective barrier behavior. (C) 2018 Elsevier Ltd. All rights reserved.