First reported self-healing polymer that spontaneously and independently repairs itself

A cylindrical sample of the elastomer mends itself after being cut in two by a razor blade and can be manually stretched without rupture

The researchers have dubbed the material a 'Terminator' polymer in tribute to the shape-shifting, molten T-100 terminator robot from the Terminator 2 film.

The research is published in the Royal Society of Chemistry journal Materials Horizons.

Self-healing polymers that can spontaneously achieve quantitative healing in the absence of a catalyst have never been reported, until now. The scientists prepared the self-healing thermoset elastomers from common polymeric starting materials using a simple and inexpensive approach.

A video shows that the permanently cross-linked poly(urea-urethane) elastomeric network completely mends itself after being cut in two with a razor blade. A metathesis reaction of aromatic disulphides, which naturally exchange at room temperature, causes the regeneration.

The polymer behaves as a Velcro-like sealant or adhesive, displaying an impressive 97 per cent healing efficiency in just two hours. The researchers show that after cutting the material into two separate pieces with a razor blade and allowing it to self-heal, the material is unbreakable when stretched manually.

The authors said: "The fact that poly(urea-urethane)s with similar chemical composition and mechanical properties are already used in a wide range of commercial products makes this system very attractive for a fast and easy implementation in real industrial applications."