Self-Healing Structural Materials for Damage Tolerant Aerospace Vehicles

The proposed  effort describes how to develop novel lightweight, self-healing systems where self-repair is induced by the forces imparted by the damage event itself.  This is possible because damage is induced by an energetic source – high velocity projectile impact. By designing the molecular composition of a polymer to contain mechanoresponsive functional groups, it is possible to induce self-healing through the transformation of such chemical groups to a state where mechanical properties of the structure are almost completely restored, within fractions of seconds after the damage event occurs. The forces imparted by the damage event can therefore be used to enable healing or repair of the structure. The ability of a material to autonomically react to changes in its environment lends itself to potential applications that mitigate some of the risks that have been identified for long duration human exploration beyond LEO.

Designing and synthesizing a structural polymer matrix that has the inherent ability to self-heal within fractions of seconds after impact damage is incurred, greatly improves vehicle safety by increasing the design allowable for strength, resulting in more efficient CFRP structure.  A new structural polymer is envisioned such that recovery can occur autonomously or be activated after an application of a specific stimulus (e.g. heat, radiation). Effective self-healing requires that these materials heal quickly following low - mid velocity impacts, while retaining structural integrity.

The objective of this work is to use an unconventional polymer synthetic route to develop lightweight, self-healing structural materials to enable more damage tolerant systems.  The proposed work will involve the molecular design of polymers with compositions that contain mechanoresponsive chemical functional groups and the determination of synthetic conditions.