Now, materials that repair themselves

Washington, April 18 : Researchers have used two methods for the development of self-repairing polymer materials with the capacity of recovering a good part of the properties lost and with no or with minimal external help.

The two notable self-repairing technologies in polymer materials are adhesives and thermal encapsulation.

As the name suggests, the first of these involves a series of "stores" of adhesive found distributed in the most homogenous manner possible throughout the material, so that when the crack reaches one of these nodes the adhesive is secreted, together with a catalyst, and the crack is closed and the material polymerised.

There are two variants within this line of technology, depending on whether adhesive-containing microcapsules or tubes filled with adhesive are employed.

INASMET-Tecnalia has worked on this line in a project undertaken for the AIRBUS, having managed to produce a series of microcapsules and distribute them in a polymeric resin.

The second method, developed by Bristol University, is a project for the ESA (European Sapce Agency), is very similar. The difference lies in the use of tubes rather than microcapsules filled with adhesive.

The thermal method uses a different repair methodology.

The material, developed by the University of Sheffield, is a polymeric matrix compound, reinforced with carbon fibres. The polymer matriz, in turn, is made of a solid solution of a thermoplastic polymer and another thermostable polymer.

It should be underlined that the development of self-repairing materials is still at initial stages and there is a long way to go yet before reaching the desired goal. part from participation in this project, INASMET-Tecnalia is working on a number of research lines related to the growing demand that is anticipated for self-repairing materials.

ANI