Ballistic self-healing capability of polymeric materials for aeronautical applications

Among all the smart functionalities, self-healing has gained a raising interest in literature over the last few decades. Designing materials with the capability to recover partially or totally their integrity, the lifetime of objects is longer, their use is safer and, simultaneously, the material waste and energy consumption are reduced. In this scenario, polymers in the form of ionomers and copolymers are a valid example of intrinsic self-healing thermoplastic material since, without adding any external healing agent, a thermal stimulus allows a spontaneous restoration of the material integrity after a ballistic impact. This smart functionality makes these polymers suitable for multilayer composites for spacecraft debris protection shields and self-sealing layers in tank reservoirs for low-velocity impact. The present study is aimed at exploring the healing mechanism of this new class of polymers and to understand their applicability according to the aeronautic needs and which are the current limits for their implementations in aeronautical structures.