The project, funded under the EU Framework Program 7 (contract no.605412), is titled “Self-HealIng polymers for concepts on self-repaired aeronautical composites”, short-named HIPOCRATES in honor of the father of healing. It is a 36-month activity, targeting the development of self-healing strategies and material developments; from chemistry to final composite processing, for delivering aeronautical composite parts with self-repair.
A composite aero-structure with self-repair capabilities will offer durability, extend its service life and prolong maintenance protocols leading to lower aircraft operational costs. Despite the extensive research activities in the area of self-healing resins applied to composite materials, the research for aeronautical applications is currently very limited. To this end, the main objective of HIPOCRATES is the development of self-repair composite materials by transforming widely used resins within aeronautical industry to self-healing materials.
Taking into account the current technological maturity of self-repair, secondary structural composites shall be targeted. The transformation will be done through the epoxy enrichment with appropriate chemical agents, following three main strategies:
- The nano-encapsulation strategy that involves incorporation of nano-encapsulated healing agents and a dispersed catalyst within a polymer matrix
- The reversible polymers strategy where remediable polymer matrices follow the Diels-Alder chemical reaction rendering damage repairable through triggered reversible cross-linking.
Combinations of these technologies will be tried for the first time. For all strategies the current progress of nano-technology will be utilized towards either better facilitation of self-healing process (e.g. nano-carriers) or enhancement of the self-healing performance or integration of other functionalities (e.g. monitoring of the self-healing performance, activation of DA reaction). Manufacturing challenges that arise from incorporating such self-healing thermosetting systems into fibrous composites (prepreg, infusion/RTM) shall be closely investigated to ensure the effective transfer of the desired properties to the large scale as required by industrial processes.
It is expected that the developments shall have a high potential for spill-out effects to other application industries where composites find use.