Healing Process Affected by Morphology of PCL/Epoxy Blends

In this study, a blend of epoxy and polycaprolactone (PCL) was prepared to investigate its ‎properties. Different weight percentages of thermoplastic PCL (0.25, 0.5, 1, 2 wt%) were ‎combined with epoxy coatings. The final morphology revealed PCL scattered as spherical ‎particles within the epoxy phase, which was functioning as a continuous matrix. The coating ‎showed toughness and rigidity when it had fully cured. The PCL phase had a special behavior ‎when heated, called "bleeding," in which it filled any open surfaces of its own volition. By ‎using molten PCL to fill in cracks, this property can be used for self-healing applications. The ‎self-healing efficacy of blends with different PCL contents was assessed. The self-healing ‎efficacy of the various mixes was determined by dividing the width of the self-healed crack by ‎the width of the original crack. The results showed that the highest thermal-mending efficiencies, ‎reaching 100%, were achieved with a PCL/epoxy blend containing co-continuous phases, ‎specifically at a 1 wt.% PCL content. Fourier-transform infrared (FTIR) analysis indicated that ‎there was physical interaction between the epoxy and PCL phases, but no chemical bonding ‎occurred between them.‎