Assessment of Self-healing Efficacy of Thermoplastic Ionomer Films Interleaving Carbon-Fibre Reinforced Epoxy Matrix Laminates

Abstract

Abstract:In recent years there has been a strong interest in thermoplastic polymers with self-healing behaviour, which after suffering mechanically-induced damage self-repair via energy-activated macromolecular rearrangements. The use of film-shaped self-regenerating polymers in alternating layers with high-performance continuous fibre-reinforced thermosetting polymer matrix laminates is considered particularly attractive in the mitigation of impact damage in high-demanding components and structures, insofar as the self-healing films may at the same time toughen the base fibrous thermosetting matrix laminate composite while providing immediate or subsequent self-repairing according to the above mentioned mechanisms. In this work, mechanical flexural testing along with infrared thermography inspection is proposed for characterizing low temperature (typical of the altitudes in which modern civil and military aircrafts travel) transverse low-energy ballistic impact damage (commonly occurring under the above cited conditions) in thermoplastic ionomer films interleaving carbon-fibre reinforced epoxy matrix laminates, as well as to assess the degree of success of thermally-activated self-healing process of ionomeric phase by external heating sources. Preliminary mechanical results supported the self-healing hypothesis of impact damaged hybrid laminates, and exploratory thermography imaging of both the as-damaged and as-rejuvenated test coupons suggested that this nondestructive evaluation technique is sensitive enough to detect healing effects.