Effect of time on healing behavior of microvascular channels based self-healing E-glass fibers/epoxy composite under flexural and tensile loadings condition

The occurrence of damage is an unavoidable fact in polymer composites. Damage modes in polymer composites are delamination, surface cracking, polymer cracking, etc. The presence of self-healing could extend the service life time of structure via preventing of damage growth. In this study, a self-healing E-glass fibers/epoxy composite based on micro-vascular channels has been fabricated and focused on the repair of the structure through the delivery of self-healing agents. The specimens were fabricated by hand lay-up route, while the fabrication of microvascular channels was conducted through creating solid preforms and then removing them. Since an important factor for effective healing of this structures after damage creation is high fluidity and suitable miscibility in the damage area, so anhydride resin-hardener system was used because of the higher fluidity in comparison to the amine resin-hardener. The aim of this study is to investigate the role of healing time for achieve of system optimum healing efficiency. To do so, microvascular channels with a constant volume fraction (4%) were incorporated in the composites. The flexural and tensile behavior of the specimens were assessed during the different times (0, 4, 7 and 11 days) from the primary damage creation. After damage creation and break, healing agents present in the microvascular channels flowed in the damage area and over a time span local polymerization and restoring of structure were completed. The results showed that, the highest flexural and tensile strength recovery was obtained 59.07% and 68.05% for the specimen after 7 days from initial damage creation.