A comparative approach for self‐healing of carbon nanotube epoxy/polycaprolactone composites: Joule, Infrared, and oven heating.

The self‐healing process in PCL (polycaprolactone)/epoxy blends is studied in order to optimize the healing process and understand its underlying mechanism. For this purpose, PCL/epoxy blends are prepared with and without multiwall carbon nanotubes (MWCNTs) addition. Three different self‐healing heat‐inducement techniques are used (an oven, Joule effect, and infrared (IR) lamp) as a function of healing time (2, 5, 10, and 15 min) and PCL concentration (5, 10, and 15 wt%). The results obtained demonstrate that the addition of MWCNTs to the polymer matrix in PCL/epoxy blends accelerates the self‐healing process, attributed to an improved heat diffusion in MWCNTs/PCL/epoxy blends. The best self‐healing results were obtained with the highest self‐healing time and concentration of PCL, caused by the higher probability of the crack formation over a PCL reservoir. The most efficient techniques to induce the self‐healing process in PCL/epoxy blends with and without MWCNTs are the conventional oven and the Joule Effect, respectively, being faster the latter method, as it induces a homogeneous internal heating of the material. Moreover, Joule effect can be controlled remotely, while IR radiation is a noncontact technique, which can be applied in situ. The three heating methods are evaluated considering these factors alongside their energy efficiency, establishing a method to choose a specific heating source for similar systems. Highlights: PCL/epoxy blends reinforced with MWCNTs have been manufactured.Variable heating sources have been analyzed.The influence of the heating source on the self‐healing is studied.Joule constitutes the faster heating for MWCNTs/PCL/epoxy system. [ABSTRACT FROM AUTHOR]