Self-repairing elastomers

Scientists loaded microcapsules with an adhesive and put it in elastomers made of synthetic caoutchouc to stimulate a self-healing process in plastics.

OBERHAUSEN, GERMANY—Researchers in Germany have developed elastomers that can repair themselves.

Some plants, such as the caoutchouc tree hevea brasiliensis, conduct latex that contains capsules with the protein, hevein.

If the caoutchouc tree is damaged, the latex escapes and the capsules break open to release hevein, which links the latex particles to form a wound closure.

Scientists at Germany’s Fraunhofer Institute for Environmental, Safety and Energy Technology have applied that principal to elastomers.

They loaded microcapsules with an adhesive and put it in elastomers made of synthetic caoutchouc to stimulate a self-healing process in plastics.

“If pressure is put on the capsules, they break open and separate this viscous material. Then this mixes with the polymer chains of the elastomers and closes the cracks,” explains Anke Nellesen, a scientist at the Fraunhofer Institute.

They also put the self-healing component into the elastomer uncapsulised, which resulted in self-healing properties again.

The researchers achieved even better results by supplying elastomers with ions. The hevein proteins that are released when there is damage link up to each other through ions and stick so that the crack closes.