Rapid Self-Repairing Material

Several materials have been reported on in recent years that are capable of repairing themselves when damaged. Most consist of microcapsules filled with a glue-like material that mixes with a catalyst to solidify when the capsules are ruptured. But the fact that the curing process sometimes requires several hours limits their potential applications. For example, an aircraft or spacecraft that is punctured by debris will lose cabin pressure far too quickly for these materials to be of use.

This was particularly important to one team of chemical engineers interested in addressing the specific challenge of creating a self-repairing material suitable for use on a pressurized fuselage. They began by looking for compounds that solidify quickly when exposed to air. The key was to find a chemical which would react readily with oxygen to form free radicals, which are instrumental in joining small molecules into larger ones to create plastics – a process known as polymerization. What they came up with was a resin made of organosulphuric compounds (called thiols) and hydrocarbons (called alkenes).

To test the new resin, they sandwiched a 1-millimeter thick layer between two pieces of plastic (also 1-millimeter thick) and shot it with a rifle at point blank range. High-speed video revealed that the material rapidly transformed into a solid polymer plug to seal up the hole in less than one second.