Enhanced Self‐Healing in Glass Fiber‐Reinforced Epoxy Composites via Vascular Channels: Utilizing Ethyl‐2‐Cyanoacrylate and Interface Optimization

ABSTRACT The latent matrix micro‐cracking remains a critical challenge for fiber‐reinforced composites in high‐performance applications. Bio‐inspired self‐healing materials address this by enabling autonomous repair and mechanical restoration. In this study, the vascular channels made from glass tubes filled with ethyl‐2‐cyanoacrylate (ECA) as a healing agent were integrated into glass fiber‐reinforced epoxy composites. To strengthen the weak glass‐resin interface, a stearic acid‐hexane solution was used to coat the glass tubes. Rhodamine B acted as a fluorescent tracer to visualize ECA penetration into the fractured regions of the composites. Neat composite specimens, alongside those containing empty and ECA‐filled vascular channels, were subjected to damage under various impact energies. The self‐healing capabilities of the relevant specimens at room temperature were thoroughly investigated using three‐point bending tests, FTIR, and SEM analyses. These analyses confirmed the morphological and structural distribution of ECA in the specimens and its self‐healing efficiency. Furthermore, the highest healing efficiency (62.68%) was achieved for the specimens with 1.2 vol% ECA subjected to an 18 J impact. Quantitative microscopic analysis of the SEM images revealed that this performance is governed by the formation of optimal crack apertures and controlled vascular fragmentation, which facilitate the effective capillary delivery of the healing agent.