Scientists have always looked to nature for inspiration, as life tends to have ingenious ways of dealing with problems. According to a recent study published by the American Chemical Society, researchers in Germany have developed a tire that can heal its wounds like an animal with a cut. In addition to patching holes on its own, the tire is also incredibly sturdy on the road.
Early studies in the field of elastomers showed that it was in fact possible to develop a material that would patch its own wounds. Researchers wrote about a supramolecular rubber based on light compounds like fatty diacids and triacids. These compounds bind together to form long cross-linked chains with strong hydrogen bonds. This allows them to spread out across a hole in the material, eventually filling in the gap. Despite early promising results, the researchers failed to demonstrate that this material could be strong enough for practical uses.
The call from tire and rubber industries for a durable self-healing material led researchers to begin studying bromobutyl rubber, or BIIR, which showed serious promise both in strength and self-healing abilities. BIIR was shown to react with chemicals called amines, which allowed ionic functional groups to heal gaps in the material. Researchers began to realize that noncovalent interactions played an important role in self-healing behavior.
The recent study examining a specific reaction with a new kind of bromobutyl rubber showed that the ionic nature of the network successfully rearranged in a way that could indicate improved durability to damaged material. Butyl rubber usually consists of isobutylene and a small percentage of isoprene, but its cross-linking efficiency isn’t very good. The study found a new mix of chemical components that improved upon the efficiency and durability of self-healing tires, and added to the growing collection of research supporting the development of self-healing materials.
They even tested the new material out in tire form. You can check out a video here: