Self-healing and stimuli-responsive shape memory in PCL/Epoxy/Tannic acid systems: Synergism of Bioepoxy and biocuring agents

In the pursuit of advanced materials with superior mechanical properties and functional versatility, bioepoxy composites have emerged as promising candidates for a wide range of applications. These composites, when reinforced with polycaprolactone (PCL), demonstrate a unique combination of strength, durability, and responsiveness to external stimuli. Bioepoxy composites were fabricated by incorporating 3, 5, 7, 10, 15 and 20 wt% of PCL with respect to the weight of bioepoxy matrix and curing using a biobased curing agent tannic acid, leading to the development of materials with remarkable mechanical properties and shape memory efficiency. Notably, composites with 5 wt% PCL exhibited an impressive 520.47 % enhancement in flexural strength. Additionally, these composites displayed chemo-responsive shape memory behaviour towards methanol and acetone, highlighting their potential for smart material applications. The composites also demonstrated outstanding self-healing capabilities, with the 5 wt% PCL sample attaining an impressive self-healability rate of 94.90 %. Rheological modelling provides deeper insights into the flow dynamics, further elucidating the influence of PCL concentration on the material's performance. These findings underscore the potential of PCLreinforced bioepoxy composites in applications requiring enhanced mechanical strength, responsive shape memory, and tailored rheological properties, paving the way for innovative use of the material in various industrial and technological sectors.